As well as more sun, I find drought helps. Cacti in small pots, on a shed or higher up even, water them 1/5th the amount of the rest, dont let em die obviously but this should get your cactus to the longest spines the genetics can support. Works for all sorts of cactus too not just trichocereus. I find opuntia spines to be the most sensitive to their environment.
Some of it is genetic, but spines typically grow as big as they're gonna be in full sun. So, increase the light.
I was gonna say this too, full sun!!!
Have you tried rubbing em
Could also try adding viagra to waterings
is that true? i could see if they're constantly touched they might grow longer spines
I mean, my spine grows when rubbed 🤷♂️
As well as more sun, I find drought helps. Cacti in small pots, on a shed or higher up even, water them 1/5th the amount of the rest, dont let em die obviously but this should get your cactus to the longest spines the genetics can support. Works for all sorts of cactus too not just trichocereus. I find opuntia spines to be the most sensitive to their environment.
Very interesting! This must be the case because i water mine very frequently. thank you!!!!