They grow twice per year, normally when the spirits are at the most potent. Early Spring you need to know where to look, and then in late Autumn is another time. I've seen two collected, by myself and Gandian, but it took a lot of digging to find them. As in literal digging.
I wish you luck, but if you search for it, I will accompany you; if you are willing to assist me during a Summon Catalyst casting I plan to do the Saturday morning of market.
- Asher