Anyone who has put effort into "active" cacti studies, may more or less arrive to the conclusion that their middle name is "variance" as far as potency is concerned. Variance between species, variance between different clones, variance between growing conditions and many hints at variance even at harvest time. Many factors seem to be influencing potency and many theories are at wild : some say that cacti can become more potent if stressed, others swear by well kept, well fertilised cacti. Some say that cacti cutting are best kept at dark for some time before being furtherly processed, others find no issues using them "as is".

As far as i am aware, there is no conclusive study on those factors given that there is no conclusive study even at species/clone level- i remember at one time Keeper Trout (who i believe has done quite some scientific standard work on cactus potency) declaring his work as "yes there is some info on some speciments, and thats all, variance applies" and furtherly commenting that while the topic of the research might be inadequate for an academic thesis it might be more suited and more usefull to "amateurish" researchers (Keeper Trout, if you are reading this, keep in mind that i am paraphrasing what i understood you said and, of course, corrections are more than welcome).

So, after the long and propably uneeded introduction, the question is : Is there a consensus on when to harvest cacti and under what conditions for maximum potency?

I'm just a fellow answer seeker like yourself...

To which I'd add the question:

Should the consensus on best harvest time be separated into cultivated/indigenous?

I'm moving next year to an area where echinopsis pachanoi grows, and I'd be interested in all of the same details, but I'm not sure if there's a difference played between growing wild and cultivated.

I am mostly interested in the "cultivated" parameter, since this is my situation but still any insight on both would be welcome and useful. Cultivated may have the advantage of being more under "controled" conditions plus apply to many more "westerners"

I was wondering if a cactus might taste of nutrients if you fed it some short time before you harvest. "Short time" being relative, I would say within 6 months of harvesting?

Just curious since cactus is so bitter I didn't know if the taste would be further ruined if you didn't flush the nutrients somehow.

Seems to me that wintertime is better