cactuscarl Posted November 22, 2012 Hi all does anyone know what determines spine length? A few of my cacti are shooting ridiculously long spines twice the length of last year. My psychoO has a pup with 10-12cm spines where as the stock spines are about 7cm. One of the cuttings I took off it is shooting away and the spines are about 2cm, weird. The one with short spines is in a different location so I'm assuming that's why the spines are shorter but the other hasn't been moved for over two years Share this post Link to post Share on other sites
J Smith Posted November 22, 2012 Genetics and growing conditions. Apparently a cactus grows longer spines in a sunnier position - it's suggested it's to create shade. 1 Share this post Link to post Share on other sites
PhoenixSon Posted November 22, 2012 (edited) I thought i remember reading that high amounts of water will make tricho`s throw longer spines dont know if this is true tho.. Edited November 22, 2012 by spacemonk Share this post Link to post Share on other sites
nitrogen Posted November 22, 2012 For sure sun exposure is the single most potent variable, from what I've seen - more sun = longer spines.. 1 Share this post Link to post Share on other sites
Stillman Posted November 22, 2012 I found the trichos in my hot house have ridiculous spines compared to the same stock in shade, I thought it might be a stress "mechanism" because in my case its not just sunny its 10 degrees hotter with 25% humidity added. 1 Share this post Link to post Share on other sites
