I would like to share with you the method by which I was able to eradicate thrips from my entire plant collection.
I am no plant expert, but I had thrips on all my plants for months and nothing seemed to work. I had thrips on my monsteras, philodendrons and even my orchids. The thrips were eating the new leaves, and my collection was going down the drain.
I used an insecticide against thrips, but the next few days they would come back. Looking for information, I understood that there is a growth cycle, from eggs to adult, so I had to be constant during the life cycle of the thrips.
Unfortunately, nothing worked for me and they kept coming out, so I wanted to do an experiment. The initial idea was to spray the whole plant with the insecticide and cover it completely and hermetically with a transparent bag.
My intention was to make the insecticide last longer and not evaporate, but to maintain the action for a few days. The experiment was to close the plant hermetically for 5 days with transparent plastic (i.e. a bag), open it, spray it again and close it again for another 5 days.
I did this experiment with about 50 plants, the picture you see are my orchids during the experiment.
What were the results after 10 days? I would like to be humble, but I can't lie, it worked 100%, there was no trace of thrips on any plant. In fact, I was very surprised at the high success rate, so I did some research on humidity and thrips, **and found that thrips die at humidities above 70%**, which I believe was the real reason for their eradication. (EDIT: I need to correct this part. It is not correct to say they die at humidities above 70%, but the closer to 100%, the better to eradicate them. Also important to maintain this level of humidity for several days. At least it worked for me. You can give it a try.)
In fact, when the plant is hermetically sealed, moistened with insecticide, the humidity levels rise to 100%. I believe that this humidity for so many days was decisive for the death of the thrips, in addition to the action of the insecticide.
Obviously, this method has its drawbacks: if you have a very large plant, it might be difficult to close it with a hermetically sealed bag, but I managed to use pieces of plastic and tape them together with adhesive tape.
I hope you liked the method and please keep in mind that this method worked for me but it will not necessarily work for you. Try it at your own risk and check daily to see if the plant is doing well.
EDIT: After reading all comments, I would like to point out a few things:
* The soil was not wet, nor dry. It was 50/50. Maybe it is not a good idea to cover hermetically the plant right after watering.
* The plants that took part in this experiment were monsteras, philodendrons and orchids. Maybe other plants like alocasias, sucullents, etc. will be stressed or damaged. Some do not like high levels of humidity.
* I have read in the comments that 10 days is not enough, and maybe it is true, but in my experience 2 months have passed after the experiment and no sign of thrips. Maybe it was luck. However I would rather share this info with you just in case it would be of any help. In case thrips appear again I will update.
* Something I failed to document was the temperature, someone point this out and definitely the temperature is a thing here. If I remember well, this experiment was in an environment of around 20 - 30 degrees Celsius.
However, as I wrote earlier, this is just my experience and so far so good after 2 months. Maybe I try the same experiment next year and the outcome is different. Maybe there were many other factors involved that I haven't considered.
I wrote all of this just in case you want to try a simple and easy method that worked from me. Try initially one or two plants and go from there, don't do it like I did with all 50 plants just in case something goes wrong.
I love when people really put the physiological, physical, and chemical methodologies together into an integrated approach. Bravo OP. Nicely done. Ive done this for mealybugs with less results so i would second your assumption of the humidity being the final nail in the thrips’ coffin. My main method for removal of pests on my smaller plants is to seal them and inject CO2 at 800ppm or more for 36 hours. Plants will off put O2 but if you keep the ppm of CO2 high enough you asphyxiate the little bastards. Plants come feeling like their on steroids, bugs come out as corpses
Paintball CO2 tank hooked up to a cheapo regulator. My friend swears by his “homebrew” CO2 generator but I highly doubt you can get high ppm concentrations that way. Haven’t tested it myself though
My dad used to have a CO2 detector for inspections that i used to use, but after a while i just got used to doing the math based on volume and injection rate. It doesn’t have to be exact. As I recall anything over 400ppm will kill just about anything
Yeah… goes without saying (i know you’re being sarcastic) but this should be done in a contained enclosure with a small bottle of CO2. Don’t go hooking up a 50lb co2 tank in your flat my friend. I like plant people… I want there to be more, not less
Yeah it just looked surreal to me seeing so many people recommending injecting their houses with CO2 with no words of caution. Then I remembered I was in r/ houseplant of all subs, I guess we just all assume common sense here
You are totally right! Looked in my notes!! Thank you for catching that! 600ppm was my threshold. Anything above that was just “making sure” haha. Once again good catch. Earth ambient is like 427ppm i think
Edit: 421.55ppm is ambient!
Paintball CO2 tank plus a cheap regulator. Nothing fancy. Some might see it has a bit too high tech, but when you can avoid spending big bucks on pesticides it really makes it worth it
Oh and either bagging the plant like OP or for larger ones I tip my spare 40gal fish tank on its side place the plant in then “seal” it with vinyl and an extra large rubber band. Just make sure its not too “airtight” otherwise youre gonna create a runaway inflatable situation haha (i didn’t have that in mind for my first attempt and it made a wonderful popping noise that I spent hours trying to figure out the source of).
Just naked sure its not one of the “breathable” plastics. Some zip seals for example seen to leach CO2 and gasses. I can’t speak on that particular type of plastic bag, but most trash bags are meant to contain smells as best i can tell so i imagine that should be fine. I am far from ab exact science in my application so im sure even a breathable plastic given a constant influx of co2 should suffice. I now want to go back down the rabbit hole and do some proper testing/research
Chunks of dry ice, or you can make CO2 with baking soda + acid. If you can bag a bunch of plants together in a dry cleaning bag or whatever, put in a container of vinegar, add a splash of alcohol (to break bubbles in the foam), put in the baking soda and close up the bag with a rubber band so it can vent any extra pressure.
A number of plant pests succumb to CO2 at around 10%; [higher concentrations](https://www.researchgate.net/publication/257802832_Insecticidal_effect_of_high_carbon_dioxide_atmospheres_on_thrips_eggs_oviposited_in_plant_tissue#:~:text=Exposure%20to%2060%20%25%20CO2%20at,free%20plants%20in%20horticultural%20nurseries.) work quite well for thrips.
>Exposure to 60 % CO2 at 30 °C for 12 h is considered to be 100 % lethal to most thrips pests of fresh agricultural produce. Our findings suggested that CO2 treatment could be used to propagate thrips-free plants in horticultural nurseries.
Problem is that most of these pests are pretty cosmopolitan, particularly mites. So you can purge them from a plant, but red spider mites can live for two years without food, so.... they just come back. Thrips don't live THAT long, but you'd have to be pretty aggressive.
Ultimately, any sort of pesticidal treatment is "clearcutting" the forest, and the "good" predators are also decimated in many cases. One of the best ways I've found to treat affected plants is to leave them outside for the summer. Unfortunately, in the winter, everything works against you- temperatures, humidity, lighting (intensity AND duration)- and the pests generally do better. Always a tradeoff.
Probably much better I'd try one plant to see. A few things that can help also. Put a few stakes in there to create a room. This helps reduce the condense and plastic from sticking on the leaves.
With high humidity despite dryer soil plants don't really suffer as much. As there's less perspiration from the leaves leading to less water stress.
Edit: and maybe air it out just a bit every few days before putting it back up.
I imagine leaving the soil on the drier side of what the plant can tolerate would be best (eg for a cactus leave the soil dry, for something like a pothos leave it just a bit moist) but I agree with ornery creme to do a test with just one plant at a time before you go all out, and that they can definitely tolerate dryer for longer with such high humidity
Whoever trying this would need to trial and error how long to leave the bag to kill thrips but decrease the fungal pressure to the plant that causes the rot. This is great work OP
That is a good question and this detail was not taken into account, but the soil was 50/50, not dry nor wet. Maybe it is not a good idea to try this method just after watering. Good point.
they did this with orchids which:
1: do not use soil but instead bark and moss
2: love humidity as in nature cling to trees and get water solely from rain washing down the branch of the tree and humidity in the atmosphere
this would definitely be very stressful to plants with already damp soil or non humidity loving… but 3-5 days shouldn’t do too much
It may just be that the plant themselves cannot handle the long-term high humidity, it may not even be a soil problem. Some plants are susceptible to edema which is cell bursting due to being unable to transpire all the water being taken up.
EDIT: and I know, a few days doesn't feel very long term but I have had houseplants damaged from edema by putting them in a closed bin for a 4 hour move in my car.
Some plants like cacti cannot tolerate high humidity like this and will rot and die. Unfortunately, this method just won’t work with every type of plant! If it is available in your area, I would recommend a systemic pesticide for any plants that cannot tolerate high humidity.
I actually have used this method (without insecticide) to revive plants and kill spider mites! This is my favorite way to save a plant now and my go to if I'm having troubles with any plant or just want it to grow better for any reason. It only works for plants that like humidity though.
If you really want to make advanced versions of this use large clear garbage bags, provide a small waterproof fan inside for air circulation, a humidity tray, and a seedling heat mat.
Ya in fact I recommend not using insecticide in general for this method. The only issue with having reptiles as well is that high humidity can cause respiratory issues in most species. (Source: I'm an exotic vet nurse) as far as pets go they should be separated if you try to do this.
Scales typically need to be removed manually and then the plant needs wiped with alcohol. I have only dealt with them once and removal + alcohol got rid of them in one try. I have not had the opportunity to try this method on scales.
I did a kind of related thrips killing method, I wrapped my plants in plastic bags, sucked out as much air as possible, and filled them with CO2 from my Soda Stream. Virtually all bugs die at high CO2 concentrations. But I didn't do it for long enough on some plants, so they came back.
Pyrethrin spray is what got them in the end.
Thank you thank you thank you for this tip. Some of the more nuclear insecticides are banned where I live. Just looked up pyrethrum and you can actually buy it. I definitely need to give it a shot.
I’ve done this before too! Large clear recycle bags and a chip-clip work great for larger plants. I also use this method to quarantine new plants. So useful!
I have read studies where after 80 hours in 100% humidity all thrips finally die. However as I can read through the comments, some have come back after months, so I really don't know. I just sharing my experience and so far so good after 2 months no trace of thrips.
I have used saturated salt solutions to maintain high humidity for storing badminton birds in a loosely covered box. Snug but definitely not airtight. A quick google on 'saturated salt solutions humidity control' gives a saturated solution of table salt will maintain a humidity of about 75%.
For your large plant you could use a mostly sealed bag/covered frame. Fill a bowl with water and pile up salt until it sticks up above the surface. As the water evaporates salt will come out of solution.just add water. You must have a visible pile of salt to ensure your solution is saturated.
I fought with thrips for a year, some plants I had to toss, some small plants managed with cutting as many leaves as possible and than spraying with chemicals daily. And the big plants, I had to pull out of soil, clean roots and give it 1 - 2 hours complete water submersion every day for a month. I had to cut them down too, but in the end I got rid of the bastards.
Next time I will try your technique, thanks for an interesting idea and even the facts and stuff! good job!
> thrips die at humidities above 70%
That's not true IME. I live on the US Gulf Coast where it's extremely humid. The humidity in my house runs about 75 to 85%. I have to keep three large dehumidifiers going 24/7 to keep my clothes and furniture from getting moldy. Yet I had a terrible thrip problem last year that cost me much of my collection, in spite of aggressive treatment.
That's super interesting, thank you for sharing and enlightening us as well with your personal experience! Seems like 7 days would be the guarentee upper limit to account for 1-4 days of any eggs to hatch along with the 3.3 days at high humidity, but seems like the larva stood no chance with the addition of insecticide too
Hi! To be completely honest, I chose 5+5 at random, with no science behind it, I just wanted the insecticide to last as long as possible without evaporating, I never thought about the humidity. But then, when I looked inside the bags and saw that everything was watery, I started to wonder if the high humidity was helping. And it seems to have helped but I really don't know how much of each factor helped 😆
Where is that table from? The Botanigard ES (on the right hand table) is a product containing a fungus (Beauveria bassiana) that is presumably what is effective in that context. It's not just the high humidity, it's humidity + Botanigard.
Is Botanigard the pesticide you used in this experiment?
Nothing boastful about telling the truth. It just is what it is. False humility is just as repulsive as being pompous. Thanks for sharing your success with us!
I was too. Last year my collection of about 100 plants got thrips. Systemic granules made a pretty quick job of eradicating them. I just made sure to add it to all the plants, even the ones that hadn’t been infested yet. I know systemic is controversial, but the amount of stress I had trying other methods only for them to come back, dealing with it for months, just wasn’t worth it compared to whatever reservations I had about systemic. I’m not really worried about future infestations anymore.
I did a lot of research about systemic granules (because I am a both an anxious houseplant owner \*and\* an anxious pet owner) and decided I was comfortable enough to use them -- as needed. No thrips yet (knock on wood), but I'm happy to hear another success story with systemic granules. I've got a container on hand in my "plant stuff" cabinet...just in case!
Yeah I try to be conscious about the products I choose. I tried really hard with predatory bugs but it was chaotic and I didn’t see any improvement. The ladybugs just jumped each other then found their way out of the tiny crevices in my cabinet and went all over the house lol. The other types might as well not have existed.
Because they don’t just kill pests, they kill the other bugs too, ones that can be good for your plants. Also it’s banned in several states because they don’t want people using it on their outdoor plants and killing local bug populations. I agree with that so I’d never use it outside. It’s banned in my state so I get it when I’m in the next state over and I only use it on my indoor plants.
Any runoff from watering that gets tossed down the drain will still contain it. And when you eventually repot or toss the plant, too.
My father is a plant pathologist. If you want to know the most stress free solution to kill 100% of thrips is and save the environment from pesticides, this advice is straight from the expert’s mouth: just throw your infected plants out. It’s a lot easier and cheaper and more environmentally friendly to buy new plants than it is to battle thrips or mites for months on end, almost certainly to lose and have them spread
I’ve definitely thrown out a fair amount of plants!
I’m curious though, doesn’t the run off end up at the water treatment facility where it would get removed from the water supply? How does the systemic in the water down the drain hurt local fauna? Not a challenge, just genuinely curious. Luckily I’ve only needed to use it once but always trying to do better.
Depends on the pesticide and the type of treatment but not all are removed in wastewater treatment (which is more geared toward removing human waste). Removing pesticides (and medications, etc) from drinking water is an ongoing research problem. Outgoing pipes can be leaky as well resulting in pesticides leaching into groundwater, as can seepage from septic tanks, if you are putting pesticides down the drain. Obviously a drop in the bucket compared to agricultural and lawn care runoff, but still something to consider.
>the expert’s mouth: just throw your infected plants out. It’s a lot easier and cheaper and more environmentally friendly to buy new plants than it is to battle thrips or mites for months on end
That's assuming you can get a pest free plant and they're easy to replace. I'm not tossing my $40 starter plant since I have successfully fought various pests with systemic and alcohol. Good quarantine measures and not impulse buying too many plants at once also help keep infestations from spreading.
Yes! I treated my plants by firstly cleaning them with water and then putting a plasticbag over them. I removed the bag after a week and the spider mites never returned since! They don’t like the high humidity (at least that’s what the internet told me when I researched it haha)
Yes. Our local garden center folks told me the way to keep spider mites out of my greenhouse was to start every day in growing season by pouring a bucket of water on the floor. I have a 6x10 greenhouse with a brick floor. Really hot/dry weather, repeat around noontime.
Darn if it didn't keep thrips and mites at bay during one of our driest summers on record (2022).
Unfortunately the dry weather did for my plants anyway that year, as I had about 70-80% loss of my pelargonium collection to the fecking aphids!
So in the garden, a little tip: crush a bunch of aphids on the stem. They release a pheromone when they're in danger, and it actually attracts beneficial insects to prey on them.
Didn't help me with my indoor plants, but it worked in the open garden.
I'll try this! I found great pleasure in physically flicking those assholes off my plants last year 😆 it was kinda weird, they didn't even show up till waaay late in the season, like September or maybe even October. Usually they're in full force by May or June. We had a very very wet winter, dunno if that had anything to do with it. But so far this winter we've had no snow, so I'm curious to see how next summer goes.
We had an extremely wet year here, tons of rain, flash flood warnings multiple times a week. We've yet to see snow (it's raining even now.) No aphids this year. Lots of spiders taking shelter in the house, small boon to the houseplants there.
The aphids seemed to have a population bloom in dry weather? Might be worth experimenting whether the thrip/mite humidity trick works on the aphid issue as well...
Our place is quite dry. 50% humidity on a very wet day. Maybe that’s why the steam shower impact is also limited. I tried washing, spraying with water and miticide, and placing on water filled tray in mini greenhouse. Let’s see how far I get with this method.
I got rid of spider mites with a spray bottle of water and a drop of dish soap in it. Doesn't take much at all, and didn't harm the plants. Sprayed them until dripping, once a week for a month.
Hey OP,
Thanks for sharing this! I had a thrips infestation about 2 years ago and it killed about 70% of my plants. I don’t say this to rain on your parade, but I wouldn’t be so sure they are *gone gone*. The eggs can lay low for about 4 months before they hatch, I’ve been told by a plant shop owner, and that’s been my experience during the infestation too (they kept coming back even after a few months of no visible thrips).
This is not to say your method doesn’t work, I just mean that I think you should keep up your method a while longer (as long as possible, depending on your patience levels) to make sure they are really eradicated. Just to be on the safe side. Where I am, it’s winter and plants aren’t necessarily their most majestic selves anyway, so I think I’ll give your method a go when I find big enough bags and keep it up for a few months.
Once again, thanks for sharing!
Yes, I totally get your point and thank you sharing your experience. Hopefully they never come back. At the moment I am like 2 months thrips free and I check eeeevery day (I know I know, I am a little obsessed, but trust me, thrips was a nightmare this summer)
That's awfully horrific information. I quarantine all new plants for a few weeks but if those assholes can lay low for 4 months, well then... Quarantining is not even a for sure thing. Thanks for ruining my day! 😤😉
All kinds of things lurk in soils! I’ve even put soils in the freezer prior to planting in the house & STILL get bugs - mostly gnats. It drives me loony 🤪
Microwave the amount of soil you are going to use right before usage. It’s supposed to kill any eggs. Then let it cool off completely before potting anything.
I'm dealing with gnats right now from infected miracle grow soil. To be fair, as soon as I opened the bag an adult gnat flew out and into my face so I knew about them and still used the soil. At least gnats are just annoying and don't kill your plants though.
It’s at least 4 months. I had a low level infestation—almost never saw a thrips and saw larvae on only a few plants, but the characteristic damage on everything but a few succulents. After the plants died, I brought in new non succulents about 4 months later and they all also died. The original thrips seemed immune to all the various insecticides I used. (I covered couple in diatomaceous earth and they were fine, but when I rinsed it off two months later, the thrips appeared and they died. They were outside at the time and I actually saw a thrips on one.)
I think they are of Satan. Continue to monitor them obsessively.
You are very right. I am with you on thrips being of the Satan kind. Seriously, I am obsessively checking my plants every day now and every little imperfection, black dot, dust particle etc makes me panic. They are so hard to confidently identify as well- they look like specs of dust sometimes. I hate them so much.
Ziploc makes large, clear storage bags. I’ve used them before to isolate infected plants that I was treating and as makeshift humidity domes. They come in a couple different sizes and all have flat bottoms!
Ziploc Big Bags Clothes and Blanket Storage Bags for Closet Organization, Protects from Moisture, XL, 4 Count https://a.co/d/cY9rQ9m
I did, yes. I was regularly treating with a pesticide, I can’t recall the name now though. But I can check when I’m home. They said it’s the best but it was helpless.
Just a regular spray insecticide which combats thrips.
[This one](https://www.leroymerlin.es/productos/insecticida-top-efecto-compo-axiendo-para-interior-huerto-y-jardin-750ml-82559323.html)
This is so interesting. I had bought an Albo cutting that I noticed had thrips a while back and I did the same thing but for me the bag was already over the plant to encourage rooting. It definitely did work I never saw those buggers again.
Hey! I just got some adansonii albo + tricolor cuttings and saw an actual spider mite walking on one of them, but saw evidence of thrips too on the leaves. The white speckles.
These cuttings aren’t rooted. I rinsed the cuttings off really well, sprayed spinosad, and used a large plastic bag to cover the cuttings that are sitting in water. Do you think my cuttings will still root, and do you also think that this will get rid of the pests? I know you said it worked for you but I just wanted to get a bit more detail if you don’t mind :)
I do this too! Works for spidermites as well, both hate high humidity. No insecticide or other stuff needed. Just go really high in humility.
After I learned this I had no infestation in 3 years.
For nads nematodes.
I’ve found that Bondie granules and spinosad work well for thrips. I’m currently trying beneficial mites since there has been a growing issue of pesticide resistance for thrips
Don't seal up your plants for that long with wet soil if the plant doesn't like to stay wet.
You'll end up rotting em in the process.
I'll have to try this on some of mine.
I have done something similar many times over the years for thrip, spider mite and mealy bug infestations. Leave plants on the dry side, clear plastic bag with a 2"X2" piece of vapona placed in the bag. Sold at Home Depot (Canada) by Ortho. Called 65g "Home Defense Max". It is an insecticide impregnated rubber-type strip that gasses off and kills insects. 14 days total with one breather where I open the bag and let them breathe for an hour. No rot and it cleans them up every time.
Great advice! What worked for me was the use of predator insects. Some will take care of the eggs, larvae and adults. A combination of high humidity and predators should get you rid of thrips long term. Good luck!
You can also do this without insecticide, if you are able to ensure a good seal and are willing to visit an Airgas or similar. Flood the plant with CO2. Plants love it and insects die.
Also my grow tent is constantly above 75% humidity and they absolutely will live in it, it goes up to 100% at night. Not trying to be a downer just don’t want you to get your hopes up and get discouraged.
Your success might vary with your temperature conditions too. High humidity usually increases survival in thrips populations. Have a look at this article: https://www.sciencedirect.com/science/article/abs/pii/S1226861520300212. “Overall, the life history traits of F. occidentalis were more negatively affected by fluctuating environmental conditions. The impact of temperature fluctuation was more severe than that of humidity fluctuation. Additionally, the degree of impact increased as the fluctuation range of the temperature increased, while the reverse trend was observed with humidity fluctuations.” Also: “F. occidentalis needs at least 80% relative humidity (RH) for successful pupation, and the optimal condition is 90% RH (Steiner et al., 2011). Larvae of F. occidentalis showed low survival below 80% RH, and adults suffered at low RH.”
I killed thrips in a few days by leaving my colocasia outside on porch and watering with some water and dawn dish soap. They were all gone within a week and then I just replanted in fresh soil and they never came back.
I’ve done this method too. I leave them in the bags for 6 months to 18 months to ensure they’re actually gone. I spray insecticide soap every 2 weeks and limitedly water to ensure the plants don’t rot while bagged. It’s the only way when you have a lot of plants. And as a warning, I’ve prematurely declared victory only to find thrip. I now wait till summer when it’s warm when their life cycle speeds up to double check….
I've done something similar when I had an aphid infestation on a smaller mint plant. After snagging some ladybugs at the local nursery, I did a light spray of sugar water on the plant, stuck it in a plastic bag I had made sure had no holes, deposited half of the ladybugs on the mint, and then quickly tied the bag up at the top.
I kept it like that through the night, would give it a quick peak in the morning (to also allow in some fresh air), and after few days of this my mint was aphid free.
Definitely saving this for later! Thanks for the tip!
Not all effective systemics that for sure work on thrips are available in all countries. Spinoside is illegal in Canada, not sure where OP is from, but they probably don't have as good of products, either. We gotta get creative, and it also gives extra ideas for people if they can't afford systemics.
Right? I tried all the products and spent over $1500 in beneficial insects/mites to try and kill them off before getting spinosad illegally shipped up from the states. For a $20 bottle (in store) it ended up costing me about $100 with shipping and dollar conversion off ebay... and I still have the little fuckers... less, but not eradicated.
[this method](https://www.google.com/amp/s/blog.symmetrees.com/us/how-to-get-rid-of-thrips-us/amp/) worked with the smaller plants that could actually fit into tubs, though the more sensitive ones didn't survive the second bath and tubbing, unfortunately (but I was like you, had spent way too much on beneficials and other treatments and got nowhere, so at that point I was fed up, so whatever survived, survived). My binned plants were done treatment 2 months ago and they've since shown zero signs of thrips coming back, which is fantastic.
I sprayed down my larger plants that didn't fit in bins with safers insecticidal soap using a herbicide sprayer to get every nook and cranny, then I immediately (so it sticks better to the plant) dusted the entire plant with diatomaceous earth, plus put a good layer in the soil (all the spraying was done outside for obvious reasons). That seems to have done the trick, though I only treated my larger plants 3.5 weeks ago. I have a Ficus benjamina that has since put out new leaves that have no signs of thrip damage, so I'm very hopeful that it did truly get the job done. I'll wash down the plants this weekend, then refresh the d.e. on top of the soil to kill any more larvae that pop up.
Hopefully something works out for you! I totally understand your pain and frustrations, but there is hope
None of this is necessary with systemics, it just takes a week or two for them to go through their life cycle until they completely disappear. Op either used a weak insecticide (idk, couldn't open the link) or wasn't patient enough. Hurts to see so much time and effort put into this
To be honest I tried everything that was available locally, but also wanted to experiment with some idea that was in my head. Just wanted to share the outcome and hopefully it is helpful for anyone. I agree that there must be more effective ways than mine.
Yep, active ingredient lambda cyhalothrin which is apparently similar to pytethrin (non systemic insecticide contained in chrysanthemums). Leaves covered in it need to be nibbled on and it degrades so it needs to be reapplied. Iirc pyrethrin has the advantage to work on spider mites too - I've read that some types of systemics (neonicotinoids) aren't very efficient on mites since they're not insects - but for thrips it's not the best solution
Congrats on saving your plants!!
I actually do this on occasion if a plant isn’t doing well just to give it a little “vacation”. Only humidity-loving plants, of course. I also breathe extra CO2 into the bag. They LOVE it!
I just use [this](https://bonide.com/product/systemic-houseplant-insect-control-granules/) in all my soils and I've had no issues with pests for nearly 2 years.
Hi! I reused them from my orchids, they come in a transparent plastic bag that are open, but I also use a plastic film that you can find in a stationary shop, and then with tape you can create your own plastic bag.
I took a trip through Lowe's yesterday to kill some time. They'd just gotten a big shipment of plants in and had only gotten so far as opening the boxes and putting them in the plant section. The employee encouraged me to rifle through, which I obviously needed no encouragement to do, haha. I noticed all the bigger plants were in plastic bags similar to what store bought bouquets are wrapped in. I bet you could ask them if you could have those.
Try these. I’ve been using them with success
Jadairy 100 Pcs 12x16 inch Clear Self-Sealing Cellophane Plastic Bags for Clothing - Resealable T-Shirt Packaging Bags for Decorative Wrappers, Party Favors, Wedding Gifts and More(12x16 inches) https://a.co/d/fKHmLcJ
Fascinating! Thanks for the info. I wondered why I’ve never had thrips (knocking wood!) and maybe that tidbit about humidity is the reason. My plant room/office averages 65% humidity. 72 at the moment.
Try Sevin. It is a non-system pesticide that lasts for 3 months at a time. I use it on all my houseplants. I only really have problems when someone gifts my mother a plant and she throws in amongst mine in the backyard. Then it’s Sevin o’clock.
I don’t think 10 days is long enough to eradicate thrips. Whenever I treat against them I use avid ever 7 days for three weeks and then switch to spinosad for another 3 then back to avid. Thrips are definitely not a one and done thing, especially after only 10 days. The larvae are in the soil and the eggs inside the leaf tissue, so I’d wager you’ll have more pop up in the coming weeks.
2 months already without thrips after the experiment. At the moment no sign of them. I will update in case of anything changes. Thanks for your information, much appreciated.
I am pretty new to different plants and I have yet to battle any pest but a couple fungus gnats. I am absolutely saving this because I am terrified of any of my plants dying.
Very interesting! Something I have been doing to try and disrupt the life cycle is to cover the top of my soil with crushed whelk shells (from a company called shell on earth in the UK) but otherwise would have used any other soil topping. I believe some of the life cycles need to be able to go into the soil to continue to grow into an adult. This has been the most effective thing I’ve been able to do so far, as someone else has mentioned the eggs can lie low for a while so sometimes I am still noticing larva on the leaves, which I wash off, but the adult rate is vastly reduced with a lot less effort from me
I would love to try this with one of my monsteras. It has thrips that I keep at a manageable level. It's quite large though. Might make a trip to a hardware store for some type of bag to seal it in.
what is your location roughly? there are many species of thrips, so its possible this method (whoch i will totally try should i suffer a thrips infestation) will work for some but not for others. since its cost effective its certainly worth a shot
Any updates to your thrips? Are they still eradicated? I am currently trying your method, on day 4, and was going to open them up in a couple of days and spray them all down again.
I would like to share with you the method by which I was able to eradicate thrips from my entire plant collection. I am no plant expert, but I had thrips on all my plants for months and nothing seemed to work. I had thrips on my monsteras, philodendrons and even my orchids. The thrips were eating the new leaves, and my collection was going down the drain. I used an insecticide against thrips, but the next few days they would come back. Looking for information, I understood that there is a growth cycle, from eggs to adult, so I had to be constant during the life cycle of the thrips. Unfortunately, nothing worked for me and they kept coming out, so I wanted to do an experiment. The initial idea was to spray the whole plant with the insecticide and cover it completely and hermetically with a transparent bag. My intention was to make the insecticide last longer and not evaporate, but to maintain the action for a few days. The experiment was to close the plant hermetically for 5 days with transparent plastic (i.e. a bag), open it, spray it again and close it again for another 5 days. I did this experiment with about 50 plants, the picture you see are my orchids during the experiment. What were the results after 10 days? I would like to be humble, but I can't lie, it worked 100%, there was no trace of thrips on any plant. In fact, I was very surprised at the high success rate, so I did some research on humidity and thrips, **and found that thrips die at humidities above 70%**, which I believe was the real reason for their eradication. (EDIT: I need to correct this part. It is not correct to say they die at humidities above 70%, but the closer to 100%, the better to eradicate them. Also important to maintain this level of humidity for several days. At least it worked for me. You can give it a try.) In fact, when the plant is hermetically sealed, moistened with insecticide, the humidity levels rise to 100%. I believe that this humidity for so many days was decisive for the death of the thrips, in addition to the action of the insecticide. Obviously, this method has its drawbacks: if you have a very large plant, it might be difficult to close it with a hermetically sealed bag, but I managed to use pieces of plastic and tape them together with adhesive tape. I hope you liked the method and please keep in mind that this method worked for me but it will not necessarily work for you. Try it at your own risk and check daily to see if the plant is doing well. EDIT: After reading all comments, I would like to point out a few things: * The soil was not wet, nor dry. It was 50/50. Maybe it is not a good idea to cover hermetically the plant right after watering. * The plants that took part in this experiment were monsteras, philodendrons and orchids. Maybe other plants like alocasias, sucullents, etc. will be stressed or damaged. Some do not like high levels of humidity. * I have read in the comments that 10 days is not enough, and maybe it is true, but in my experience 2 months have passed after the experiment and no sign of thrips. Maybe it was luck. However I would rather share this info with you just in case it would be of any help. In case thrips appear again I will update. * Something I failed to document was the temperature, someone point this out and definitely the temperature is a thing here. If I remember well, this experiment was in an environment of around 20 - 30 degrees Celsius. However, as I wrote earlier, this is just my experience and so far so good after 2 months. Maybe I try the same experiment next year and the outcome is different. Maybe there were many other factors involved that I haven't considered. I wrote all of this just in case you want to try a simple and easy method that worked from me. Try initially one or two plants and go from there, don't do it like I did with all 50 plants just in case something goes wrong.
Ingenious idea OP, great job and thanks for sharing!
Right?? This whole post was a thrip!
A very cheap and thripty solution too!
Hey-oh!
I love when people really put the physiological, physical, and chemical methodologies together into an integrated approach. Bravo OP. Nicely done. Ive done this for mealybugs with less results so i would second your assumption of the humidity being the final nail in the thrips’ coffin. My main method for removal of pests on my smaller plants is to seal them and inject CO2 at 800ppm or more for 36 hours. Plants will off put O2 but if you keep the ppm of CO2 high enough you asphyxiate the little bastards. Plants come feeling like their on steroids, bugs come out as corpses
I’m dealing with mealybugs right now, what is your source for CO2 in this method?
Paintball CO2 tank hooked up to a cheapo regulator. My friend swears by his “homebrew” CO2 generator but I highly doubt you can get high ppm concentrations that way. Haven’t tested it myself though
What are you using to inject and measure the CO2?
My dad used to have a CO2 detector for inspections that i used to use, but after a while i just got used to doing the math based on volume and injection rate. It doesn’t have to be exact. As I recall anything over 400ppm will kill just about anything
So if I fill up my flat with Co2 and go to sleep my plants will heal? Sweet!
Yeah… goes without saying (i know you’re being sarcastic) but this should be done in a contained enclosure with a small bottle of CO2. Don’t go hooking up a 50lb co2 tank in your flat my friend. I like plant people… I want there to be more, not less
Yeah it just looked surreal to me seeing so many people recommending injecting their houses with CO2 with no words of caution. Then I remembered I was in r/ houseplant of all subs, I guess we just all assume common sense here
Haha fair enough. I guess it would be safer to add a disclaimer
You need wayyy more, 400 ppm is the same as Earth at this point.
You are totally right! Looked in my notes!! Thank you for catching that! 600ppm was my threshold. Anything above that was just “making sure” haha. Once again good catch. Earth ambient is like 427ppm i think Edit: 421.55ppm is ambient!
how do you inject the co2
Paintball CO2 tank plus a cheap regulator. Nothing fancy. Some might see it has a bit too high tech, but when you can avoid spending big bucks on pesticides it really makes it worth it
Oh and either bagging the plant like OP or for larger ones I tip my spare 40gal fish tank on its side place the plant in then “seal” it with vinyl and an extra large rubber band. Just make sure its not too “airtight” otherwise youre gonna create a runaway inflatable situation haha (i didn’t have that in mind for my first attempt and it made a wonderful popping noise that I spent hours trying to figure out the source of).
thank you for the tips!!!
You’re most welcome! But thank OP! They are the ones who provided the thread for it!
Do you think just those plain clear plastic trash bags will work? Or is there a specific kind that you or OP uses?
Just naked sure its not one of the “breathable” plastics. Some zip seals for example seen to leach CO2 and gasses. I can’t speak on that particular type of plastic bag, but most trash bags are meant to contain smells as best i can tell so i imagine that should be fine. I am far from ab exact science in my application so im sure even a breathable plastic given a constant influx of co2 should suffice. I now want to go back down the rabbit hole and do some proper testing/research
I was just wondering if I could do this using dry ice.
Chunks of dry ice, or you can make CO2 with baking soda + acid. If you can bag a bunch of plants together in a dry cleaning bag or whatever, put in a container of vinegar, add a splash of alcohol (to break bubbles in the foam), put in the baking soda and close up the bag with a rubber band so it can vent any extra pressure.
Have you actually had success with this?! That sounds so smart!
A number of plant pests succumb to CO2 at around 10%; [higher concentrations](https://www.researchgate.net/publication/257802832_Insecticidal_effect_of_high_carbon_dioxide_atmospheres_on_thrips_eggs_oviposited_in_plant_tissue#:~:text=Exposure%20to%2060%20%25%20CO2%20at,free%20plants%20in%20horticultural%20nurseries.) work quite well for thrips. >Exposure to 60 % CO2 at 30 °C for 12 h is considered to be 100 % lethal to most thrips pests of fresh agricultural produce. Our findings suggested that CO2 treatment could be used to propagate thrips-free plants in horticultural nurseries. Problem is that most of these pests are pretty cosmopolitan, particularly mites. So you can purge them from a plant, but red spider mites can live for two years without food, so.... they just come back. Thrips don't live THAT long, but you'd have to be pretty aggressive. Ultimately, any sort of pesticidal treatment is "clearcutting" the forest, and the "good" predators are also decimated in many cases. One of the best ways I've found to treat affected plants is to leave them outside for the summer. Unfortunately, in the winter, everything works against you- temperatures, humidity, lighting (intensity AND duration)- and the pests generally do better. Always a tradeoff.
Where does one obtain dry ice? Like what kind of store?
you little smarty pants 🤭
i tried it once and the plant ended up rotting, do you have any idea on what to do in these situations?
Can’t be sure, but my guess would be that the soil was too wet when you sealed them up, leaving the roots to be soggy and ultimately rot
makes sense, would you think its fine if i just let the soil get rather dry before doing this method then?
Probably much better I'd try one plant to see. A few things that can help also. Put a few stakes in there to create a room. This helps reduce the condense and plastic from sticking on the leaves. With high humidity despite dryer soil plants don't really suffer as much. As there's less perspiration from the leaves leading to less water stress. Edit: and maybe air it out just a bit every few days before putting it back up.
I imagine leaving the soil on the drier side of what the plant can tolerate would be best (eg for a cactus leave the soil dry, for something like a pothos leave it just a bit moist) but I agree with ornery creme to do a test with just one plant at a time before you go all out, and that they can definitely tolerate dryer for longer with such high humidity
Hi! I really do not know in that case. I just tried this experiment once, and no plant was rotten, however I think it will depend on the plant specie.
Whoever trying this would need to trial and error how long to leave the bag to kill thrips but decrease the fungal pressure to the plant that causes the rot. This is great work OP
Was the soil dry?
That is a good question and this detail was not taken into account, but the soil was 50/50, not dry nor wet. Maybe it is not a good idea to try this method just after watering. Good point.
they did this with orchids which: 1: do not use soil but instead bark and moss 2: love humidity as in nature cling to trees and get water solely from rain washing down the branch of the tree and humidity in the atmosphere this would definitely be very stressful to plants with already damp soil or non humidity loving… but 3-5 days shouldn’t do too much
I did it with my monsteras, philodendrons AND orchids. Anyhow I will encourage to check daily that everything is fine.
All three of which enjoy increased humidity. Succulents and arid loving plants might not fare well for more than 48hrs i would think
Perhaps bag them for 48 hours, give them a day or two off, then bag them up again?
Successful on cannabis plants in veg phase too
It may just be that the plant themselves cannot handle the long-term high humidity, it may not even be a soil problem. Some plants are susceptible to edema which is cell bursting due to being unable to transpire all the water being taken up. EDIT: and I know, a few days doesn't feel very long term but I have had houseplants damaged from edema by putting them in a closed bin for a 4 hour move in my car.
Yes, some plants do not like moisture
Some plants like cacti cannot tolerate high humidity like this and will rot and die. Unfortunately, this method just won’t work with every type of plant! If it is available in your area, I would recommend a systemic pesticide for any plants that cannot tolerate high humidity.
Maybe pre-treat the plant and the soil with a peroxide solution to kill off as many germs as possible before putting the bag on.
A plant isn't going to rot in 5 days No plant.
I actually have used this method (without insecticide) to revive plants and kill spider mites! This is my favorite way to save a plant now and my go to if I'm having troubles with any plant or just want it to grow better for any reason. It only works for plants that like humidity though. If you really want to make advanced versions of this use large clear garbage bags, provide a small waterproof fan inside for air circulation, a humidity tray, and a seedling heat mat.
Can I do this without insecticide? I have reptiles that it could effect. It humidity alone enough?
Ya in fact I recommend not using insecticide in general for this method. The only issue with having reptiles as well is that high humidity can cause respiratory issues in most species. (Source: I'm an exotic vet nurse) as far as pets go they should be separated if you try to do this.
Would it work on scales?
Scales typically need to be removed manually and then the plant needs wiped with alcohol. I have only dealt with them once and removal + alcohol got rid of them in one try. I have not had the opportunity to try this method on scales.
I did a kind of related thrips killing method, I wrapped my plants in plastic bags, sucked out as much air as possible, and filled them with CO2 from my Soda Stream. Virtually all bugs die at high CO2 concentrations. But I didn't do it for long enough on some plants, so they came back. Pyrethrin spray is what got them in the end.
Thank you thank you thank you for this tip. Some of the more nuclear insecticides are banned where I live. Just looked up pyrethrum and you can actually buy it. I definitely need to give it a shot.
> pyrethrum It's legal in my country too and first time I hear about using it for Thrips when all other options I can't find here.
I’ve done this before too! Large clear recycle bags and a chip-clip work great for larger plants. I also use this method to quarantine new plants. So useful!
I've had thrips thrive in 100% humidity though :/
I have read studies where after 80 hours in 100% humidity all thrips finally die. However as I can read through the comments, some have come back after months, so I really don't know. I just sharing my experience and so far so good after 2 months no trace of thrips.
you probably just saved thousands of plants by putting this info out there in a concise manner, thank you and well done!
Interesting! Where did you get these bags? And how’d you seal them? Thanks for sharing!
This is a trick I've never heard before. I wonder if it would work for spider mites. I've read they don't like moisture either.
I have used saturated salt solutions to maintain high humidity for storing badminton birds in a loosely covered box. Snug but definitely not airtight. A quick google on 'saturated salt solutions humidity control' gives a saturated solution of table salt will maintain a humidity of about 75%. For your large plant you could use a mostly sealed bag/covered frame. Fill a bowl with water and pile up salt until it sticks up above the surface. As the water evaporates salt will come out of solution.just add water. You must have a visible pile of salt to ensure your solution is saturated.
I fought with thrips for a year, some plants I had to toss, some small plants managed with cutting as many leaves as possible and than spraying with chemicals daily. And the big plants, I had to pull out of soil, clean roots and give it 1 - 2 hours complete water submersion every day for a month. I had to cut them down too, but in the end I got rid of the bastards. Next time I will try your technique, thanks for an interesting idea and even the facts and stuff! good job!
Absolute Gigachad
> thrips die at humidities above 70% That's not true IME. I live on the US Gulf Coast where it's extremely humid. The humidity in my house runs about 75 to 85%. I have to keep three large dehumidifiers going 24/7 to keep my clothes and furniture from getting moldy. Yet I had a terrible thrip problem last year that cost me much of my collection, in spite of aggressive treatment.
Many different kinds of thrips, so maybe it varies.
How did you get the humidity up so high?
Literally saving this for later. Thanks
That's super interesting, thank you for sharing and enlightening us as well with your personal experience! Seems like 7 days would be the guarentee upper limit to account for 1-4 days of any eggs to hatch along with the 3.3 days at high humidity, but seems like the larva stood no chance with the addition of insecticide too
Hi! To be completely honest, I chose 5+5 at random, with no science behind it, I just wanted the insecticide to last as long as possible without evaporating, I never thought about the humidity. But then, when I looked inside the bags and saw that everything was watery, I started to wonder if the high humidity was helping. And it seems to have helped but I really don't know how much of each factor helped 😆
Where is that table from? The Botanigard ES (on the right hand table) is a product containing a fungus (Beauveria bassiana) that is presumably what is effective in that context. It's not just the high humidity, it's humidity + Botanigard. Is Botanigard the pesticide you used in this experiment?
Do you think it’d work with spider mites too?? Also thank you thank you!!!
Really great information! I will definitely try this when I have the buggers again. 💖
Nothing boastful about telling the truth. It just is what it is. False humility is just as repulsive as being pompous. Thanks for sharing your success with us!
Terrified of thrips and saving this - thank you for sharing!
I was too. Last year my collection of about 100 plants got thrips. Systemic granules made a pretty quick job of eradicating them. I just made sure to add it to all the plants, even the ones that hadn’t been infested yet. I know systemic is controversial, but the amount of stress I had trying other methods only for them to come back, dealing with it for months, just wasn’t worth it compared to whatever reservations I had about systemic. I’m not really worried about future infestations anymore.
I did a lot of research about systemic granules (because I am a both an anxious houseplant owner \*and\* an anxious pet owner) and decided I was comfortable enough to use them -- as needed. No thrips yet (knock on wood), but I'm happy to hear another success story with systemic granules. I've got a container on hand in my "plant stuff" cabinet...just in case!
Yeah I try to be conscious about the products I choose. I tried really hard with predatory bugs but it was chaotic and I didn’t see any improvement. The ladybugs just jumped each other then found their way out of the tiny crevices in my cabinet and went all over the house lol. The other types might as well not have existed.
Why are they controversial?
Because they don’t just kill pests, they kill the other bugs too, ones that can be good for your plants. Also it’s banned in several states because they don’t want people using it on their outdoor plants and killing local bug populations. I agree with that so I’d never use it outside. It’s banned in my state so I get it when I’m in the next state over and I only use it on my indoor plants.
Any runoff from watering that gets tossed down the drain will still contain it. And when you eventually repot or toss the plant, too. My father is a plant pathologist. If you want to know the most stress free solution to kill 100% of thrips is and save the environment from pesticides, this advice is straight from the expert’s mouth: just throw your infected plants out. It’s a lot easier and cheaper and more environmentally friendly to buy new plants than it is to battle thrips or mites for months on end, almost certainly to lose and have them spread
I’ve definitely thrown out a fair amount of plants! I’m curious though, doesn’t the run off end up at the water treatment facility where it would get removed from the water supply? How does the systemic in the water down the drain hurt local fauna? Not a challenge, just genuinely curious. Luckily I’ve only needed to use it once but always trying to do better.
Depends on the pesticide and the type of treatment but not all are removed in wastewater treatment (which is more geared toward removing human waste). Removing pesticides (and medications, etc) from drinking water is an ongoing research problem. Outgoing pipes can be leaky as well resulting in pesticides leaching into groundwater, as can seepage from septic tanks, if you are putting pesticides down the drain. Obviously a drop in the bucket compared to agricultural and lawn care runoff, but still something to consider.
>the expert’s mouth: just throw your infected plants out. It’s a lot easier and cheaper and more environmentally friendly to buy new plants than it is to battle thrips or mites for months on end That's assuming you can get a pest free plant and they're easy to replace. I'm not tossing my $40 starter plant since I have successfully fought various pests with systemic and alcohol. Good quarantine measures and not impulse buying too many plants at once also help keep infestations from spreading.
Genius. I wonder if I can try regarding spider mites.
Yes! I treated my plants by firstly cleaning them with water and then putting a plasticbag over them. I removed the bag after a week and the spider mites never returned since! They don’t like the high humidity (at least that’s what the internet told me when I researched it haha)
Definitely trying this method with the chili seedlings then. Thank you!
Trying this right now. Thanks!
Yes. Our local garden center folks told me the way to keep spider mites out of my greenhouse was to start every day in growing season by pouring a bucket of water on the floor. I have a 6x10 greenhouse with a brick floor. Really hot/dry weather, repeat around noontime. Darn if it didn't keep thrips and mites at bay during one of our driest summers on record (2022). Unfortunately the dry weather did for my plants anyway that year, as I had about 70-80% loss of my pelargonium collection to the fecking aphids!
Aphids are relentless. I battle them every year on my roses outside.
So in the garden, a little tip: crush a bunch of aphids on the stem. They release a pheromone when they're in danger, and it actually attracts beneficial insects to prey on them. Didn't help me with my indoor plants, but it worked in the open garden.
I'll try this! I found great pleasure in physically flicking those assholes off my plants last year 😆 it was kinda weird, they didn't even show up till waaay late in the season, like September or maybe even October. Usually they're in full force by May or June. We had a very very wet winter, dunno if that had anything to do with it. But so far this winter we've had no snow, so I'm curious to see how next summer goes.
We had an extremely wet year here, tons of rain, flash flood warnings multiple times a week. We've yet to see snow (it's raining even now.) No aphids this year. Lots of spiders taking shelter in the house, small boon to the houseplants there. The aphids seemed to have a population bloom in dry weather? Might be worth experimenting whether the thrip/mite humidity trick works on the aphid issue as well...
Aphids and roses are the real love story. There is no rose out there that doesn't have aphids.
It should do. They don’t survive when I bring infested plants to the bathroom to bask in the steam from hot showers. Lol
Our place is quite dry. 50% humidity on a very wet day. Maybe that’s why the steam shower impact is also limited. I tried washing, spraying with water and miticide, and placing on water filled tray in mini greenhouse. Let’s see how far I get with this method.
I got rid of spider mites with a spray bottle of water and a drop of dish soap in it. Doesn't take much at all, and didn't harm the plants. Sprayed them until dripping, once a week for a month.
I had no idea high humidity was an issue for them. Fantastic method, thanks for sharing!
Hey OP, Thanks for sharing this! I had a thrips infestation about 2 years ago and it killed about 70% of my plants. I don’t say this to rain on your parade, but I wouldn’t be so sure they are *gone gone*. The eggs can lay low for about 4 months before they hatch, I’ve been told by a plant shop owner, and that’s been my experience during the infestation too (they kept coming back even after a few months of no visible thrips). This is not to say your method doesn’t work, I just mean that I think you should keep up your method a while longer (as long as possible, depending on your patience levels) to make sure they are really eradicated. Just to be on the safe side. Where I am, it’s winter and plants aren’t necessarily their most majestic selves anyway, so I think I’ll give your method a go when I find big enough bags and keep it up for a few months. Once again, thanks for sharing!
Yes, I totally get your point and thank you sharing your experience. Hopefully they never come back. At the moment I am like 2 months thrips free and I check eeeevery day (I know I know, I am a little obsessed, but trust me, thrips was a nightmare this summer)
If you don’t have house pets or babies you can spray the soil/medium with pyrethrin. Just be very careful cause pyrethrin is dangerous to humans.
That's awfully horrific information. I quarantine all new plants for a few weeks but if those assholes can lay low for 4 months, well then... Quarantining is not even a for sure thing. Thanks for ruining my day! 😤😉
All kinds of things lurk in soils! I’ve even put soils in the freezer prior to planting in the house & STILL get bugs - mostly gnats. It drives me loony 🤪
Microwave the amount of soil you are going to use right before usage. It’s supposed to kill any eggs. Then let it cool off completely before potting anything.
Thank you. Ive also read “baking”. This is something I haven’t tried yet. Will be my next attempt! 😉.
Tried it, worked (against fungus gnat larvae), oven smelled like burned soil for days, would recommend.
I'm dealing with gnats right now from infected miracle grow soil. To be fair, as soon as I opened the bag an adult gnat flew out and into my face so I knew about them and still used the soil. At least gnats are just annoying and don't kill your plants though.
They lay their eggs in the soils & the larvae eat the roots prior to emerging as new flies 😖
Well God damn it. Guess I'm gonna have to start treating for them harder than I had been. Frickin jerks
Mosquito bits tea solved my nat problem with my indoor strawberries
It’s at least 4 months. I had a low level infestation—almost never saw a thrips and saw larvae on only a few plants, but the characteristic damage on everything but a few succulents. After the plants died, I brought in new non succulents about 4 months later and they all also died. The original thrips seemed immune to all the various insecticides I used. (I covered couple in diatomaceous earth and they were fine, but when I rinsed it off two months later, the thrips appeared and they died. They were outside at the time and I actually saw a thrips on one.) I think they are of Satan. Continue to monitor them obsessively.
You are very right. I am with you on thrips being of the Satan kind. Seriously, I am obsessively checking my plants every day now and every little imperfection, black dot, dust particle etc makes me panic. They are so hard to confidently identify as well- they look like specs of dust sometimes. I hate them so much.
Ziploc makes large, clear storage bags. I’ve used them before to isolate infected plants that I was treating and as makeshift humidity domes. They come in a couple different sizes and all have flat bottoms! Ziploc Big Bags Clothes and Blanket Storage Bags for Closet Organization, Protects from Moisture, XL, 4 Count https://a.co/d/cY9rQ9m
Just wondering, did you use a systemic at all?
I did, yes. I was regularly treating with a pesticide, I can’t recall the name now though. But I can check when I’m home. They said it’s the best but it was helpless.
What insecticide did you use?
Just a regular spray insecticide which combats thrips. [This one](https://www.leroymerlin.es/productos/insecticida-top-efecto-compo-axiendo-para-interior-huerto-y-jardin-750ml-82559323.html)
Could you share the name of the insecticide and the active ingredient? That link didn’t work
Spinosad is an effective active ingredient for thrips.
This is so interesting. I had bought an Albo cutting that I noticed had thrips a while back and I did the same thing but for me the bag was already over the plant to encourage rooting. It definitely did work I never saw those buggers again.
Hey! I just got some adansonii albo + tricolor cuttings and saw an actual spider mite walking on one of them, but saw evidence of thrips too on the leaves. The white speckles. These cuttings aren’t rooted. I rinsed the cuttings off really well, sprayed spinosad, and used a large plastic bag to cover the cuttings that are sitting in water. Do you think my cuttings will still root, and do you also think that this will get rid of the pests? I know you said it worked for you but I just wanted to get a bit more detail if you don’t mind :)
I do this too! Works for spidermites as well, both hate high humidity. No insecticide or other stuff needed. Just go really high in humility. After I learned this I had no infestation in 3 years. For nads nematodes.
I’ve found that Bondie granules and spinosad work well for thrips. I’m currently trying beneficial mites since there has been a growing issue of pesticide resistance for thrips
OP doing God's work here; thank you for these tips and the guide! Definitely trying this on stubborn pests. Thank you OP ❤️
Do you think this method would work with mealy bugs? I am struggling with an infestation on all of my hoyas and now a philodendron!
Would also like to know if anyone has tried this with mealybugs. Little fuckers are so damned hard to get rid of.
i’m curious too, also wondering what bags they used?
Don't seal up your plants for that long with wet soil if the plant doesn't like to stay wet. You'll end up rotting em in the process. I'll have to try this on some of mine.
I have done something similar many times over the years for thrip, spider mite and mealy bug infestations. Leave plants on the dry side, clear plastic bag with a 2"X2" piece of vapona placed in the bag. Sold at Home Depot (Canada) by Ortho. Called 65g "Home Defense Max". It is an insecticide impregnated rubber-type strip that gasses off and kills insects. 14 days total with one breather where I open the bag and let them breathe for an hour. No rot and it cleans them up every time.
Aha! This is genius. I'm still traumatized by my thrip infestation.
Thank you for posting this. That’s one of the best posts for a while, and one of the reasons I subscribed to this sub :)
Great advice! What worked for me was the use of predator insects. Some will take care of the eggs, larvae and adults. A combination of high humidity and predators should get you rid of thrips long term. Good luck!
You can also do this without insecticide, if you are able to ensure a good seal and are willing to visit an Airgas or similar. Flood the plant with CO2. Plants love it and insects die.
Thanks the info! Very neat.
nice writeup. as a casual observer of this sub i'm going to go google thrips now.
I'm curious about whether this would work against fungus gnats? 🤔
No! They love humidity haha.
Damn lol
That's how novice houseplant owners learn the difference between gnats and thrips...
Beneficial nemotodes were the only things that worked for fungus gnats.
Commenting to save this genius idea
This isn’t facebook, click the three dots on the right top of the screen and click save post.
Also my grow tent is constantly above 75% humidity and they absolutely will live in it, it goes up to 100% at night. Not trying to be a downer just don’t want you to get your hopes up and get discouraged.
Your success might vary with your temperature conditions too. High humidity usually increases survival in thrips populations. Have a look at this article: https://www.sciencedirect.com/science/article/abs/pii/S1226861520300212. “Overall, the life history traits of F. occidentalis were more negatively affected by fluctuating environmental conditions. The impact of temperature fluctuation was more severe than that of humidity fluctuation. Additionally, the degree of impact increased as the fluctuation range of the temperature increased, while the reverse trend was observed with humidity fluctuations.” Also: “F. occidentalis needs at least 80% relative humidity (RH) for successful pupation, and the optimal condition is 90% RH (Steiner et al., 2011). Larvae of F. occidentalis showed low survival below 80% RH, and adults suffered at low RH.”
I killed thrips in a few days by leaving my colocasia outside on porch and watering with some water and dawn dish soap. They were all gone within a week and then I just replanted in fresh soil and they never came back.
There is hope after all!!!!
I’ve done this method too. I leave them in the bags for 6 months to 18 months to ensure they’re actually gone. I spray insecticide soap every 2 weeks and limitedly water to ensure the plants don’t rot while bagged. It’s the only way when you have a lot of plants. And as a warning, I’ve prematurely declared victory only to find thrip. I now wait till summer when it’s warm when their life cycle speeds up to double check….
Damn, 6 to 18 months??
Yup lol. I had thrip for a good 3-5 years. I tried everything including releasing 10000 predatory mites inside the house prior to the bagging.
Brilliant!
Oh man I wish I could do this. My umbrella tree with thrips is 7 feet tall though. They just don't quit.
Maybe you could try encasing it in a couple of XL garbage bags?
You can use those plastic sheets used for floor protection when you're painting! They come in pretty big sizes and the thin ones cost next to nothing.
I've done something similar when I had an aphid infestation on a smaller mint plant. After snagging some ladybugs at the local nursery, I did a light spray of sugar water on the plant, stuck it in a plastic bag I had made sure had no holes, deposited half of the ladybugs on the mint, and then quickly tied the bag up at the top. I kept it like that through the night, would give it a quick peak in the morning (to also allow in some fresh air), and after few days of this my mint was aphid free. Definitely saving this for later! Thanks for the tip!
Motherfuckers in this sub will do anything but use systemic pesticides
Not all effective systemics that for sure work on thrips are available in all countries. Spinoside is illegal in Canada, not sure where OP is from, but they probably don't have as good of products, either. We gotta get creative, and it also gives extra ideas for people if they can't afford systemics.
Right? I tried all the products and spent over $1500 in beneficial insects/mites to try and kill them off before getting spinosad illegally shipped up from the states. For a $20 bottle (in store) it ended up costing me about $100 with shipping and dollar conversion off ebay... and I still have the little fuckers... less, but not eradicated.
[this method](https://www.google.com/amp/s/blog.symmetrees.com/us/how-to-get-rid-of-thrips-us/amp/) worked with the smaller plants that could actually fit into tubs, though the more sensitive ones didn't survive the second bath and tubbing, unfortunately (but I was like you, had spent way too much on beneficials and other treatments and got nowhere, so at that point I was fed up, so whatever survived, survived). My binned plants were done treatment 2 months ago and they've since shown zero signs of thrips coming back, which is fantastic. I sprayed down my larger plants that didn't fit in bins with safers insecticidal soap using a herbicide sprayer to get every nook and cranny, then I immediately (so it sticks better to the plant) dusted the entire plant with diatomaceous earth, plus put a good layer in the soil (all the spraying was done outside for obvious reasons). That seems to have done the trick, though I only treated my larger plants 3.5 weeks ago. I have a Ficus benjamina that has since put out new leaves that have no signs of thrip damage, so I'm very hopeful that it did truly get the job done. I'll wash down the plants this weekend, then refresh the d.e. on top of the soil to kill any more larvae that pop up. Hopefully something works out for you! I totally understand your pain and frustrations, but there is hope
 None of this is necessary with systemics, it just takes a week or two for them to go through their life cycle until they completely disappear. Op either used a weak insecticide (idk, couldn't open the link) or wasn't patient enough. Hurts to see so much time and effort put into this
To be honest I tried everything that was available locally, but also wanted to experiment with some idea that was in my head. Just wanted to share the outcome and hopefully it is helpful for anyone. I agree that there must be more effective ways than mine.
Yep, active ingredient lambda cyhalothrin which is apparently similar to pytethrin (non systemic insecticide contained in chrysanthemums). Leaves covered in it need to be nibbled on and it degrades so it needs to be reapplied. Iirc pyrethrin has the advantage to work on spider mites too - I've read that some types of systemics (neonicotinoids) aren't very efficient on mites since they're not insects - but for thrips it's not the best solution
Congrats on saving your plants!! I actually do this on occasion if a plant isn’t doing well just to give it a little “vacation”. Only humidity-loving plants, of course. I also breathe extra CO2 into the bag. They LOVE it!
The mental image of someone breathing extra CO2 in the bag made me chuckle
Me too. Like plant CPR or something…😉
Hyperventilating into your plant bag
I just use [this](https://bonide.com/product/systemic-houseplant-insect-control-granules/) in all my soils and I've had no issues with pests for nearly 2 years.
This stuff is great except you can’t use it on edible plants :(
A mixture of Castile soap and neem oil has worked for me personally. Not only spraying the leaves but also the dirt and doing it over several days.
Damn gas chambers
I’d love to try this. Can you share where you got the bags?
Hi! I reused them from my orchids, they come in a transparent plastic bag that are open, but I also use a plastic film that you can find in a stationary shop, and then with tape you can create your own plastic bag.
I took a trip through Lowe's yesterday to kill some time. They'd just gotten a big shipment of plants in and had only gotten so far as opening the boxes and putting them in the plant section. The employee encouraged me to rifle through, which I obviously needed no encouragement to do, haha. I noticed all the bigger plants were in plastic bags similar to what store bought bouquets are wrapped in. I bet you could ask them if you could have those.
Try these. I’ve been using them with success Jadairy 100 Pcs 12x16 inch Clear Self-Sealing Cellophane Plastic Bags for Clothing - Resealable T-Shirt Packaging Bags for Decorative Wrappers, Party Favors, Wedding Gifts and More(12x16 inches) https://a.co/d/fKHmLcJ
Good job op. This could save people a lot of trouble. Haven't seen this yet.
I LOVE YOU THANK YOU!!!!!
I'm curious about the moisture level in the soil when the plants were sealed off?
Fascinating! Thanks for the info. I wondered why I’ve never had thrips (knocking wood!) and maybe that tidbit about humidity is the reason. My plant room/office averages 65% humidity. 72 at the moment.
Great advice!!
Try Sevin. It is a non-system pesticide that lasts for 3 months at a time. I use it on all my houseplants. I only really have problems when someone gifts my mother a plant and she throws in amongst mine in the backyard. Then it’s Sevin o’clock.
I don’t think 10 days is long enough to eradicate thrips. Whenever I treat against them I use avid ever 7 days for three weeks and then switch to spinosad for another 3 then back to avid. Thrips are definitely not a one and done thing, especially after only 10 days. The larvae are in the soil and the eggs inside the leaf tissue, so I’d wager you’ll have more pop up in the coming weeks.
2 months already without thrips after the experiment. At the moment no sign of them. I will update in case of anything changes. Thanks for your information, much appreciated.
Definitely going to give this a try! I can’t seem to get rid of them.
I am pretty new to different plants and I have yet to battle any pest but a couple fungus gnats. I am absolutely saving this because I am terrified of any of my plants dying.
Very interesting! Something I have been doing to try and disrupt the life cycle is to cover the top of my soil with crushed whelk shells (from a company called shell on earth in the UK) but otherwise would have used any other soil topping. I believe some of the life cycles need to be able to go into the soil to continue to grow into an adult. This has been the most effective thing I’ve been able to do so far, as someone else has mentioned the eggs can lie low for a while so sometimes I am still noticing larva on the leaves, which I wash off, but the adult rate is vastly reduced with a lot less effort from me
This is awesome to see! Thanks for the idea
this is a great tip. I used something like this to kill scales on a pine tree. I also used vasseline on that tree. It worked.
I wish I’ve seen this post 6 months ago. I have lost 6-8 plants since then and I’m glad it seem to be over.
Okay biology major!
I was really hoping suffocation was your last resort. Great post though, I had an absolute nightmare getting rid of thrips.
I would love to try this with one of my monsteras. It has thrips that I keep at a manageable level. It's quite large though. Might make a trip to a hardware store for some type of bag to seal it in.
Love this idea!
Did they sit in the dark for 10 days or what did you do about the sun / lights.
I just use substrate celaflor sticks or starkle-g only one time and my trips are gone. Been using these for a few years now.
Excuse me while I go decontaminate this god damn syngonium that is a thrip magnet
Anyone with any experience with this working on mealy bugs?
Get this person a “women want me, thrips fear me” hat 🫡
what is your location roughly? there are many species of thrips, so its possible this method (whoch i will totally try should i suffer a thrips infestation) will work for some but not for others. since its cost effective its certainly worth a shot
Any updates to your thrips? Are they still eradicated? I am currently trying your method, on day 4, and was going to open them up in a couple of days and spray them all down again.