I bought a rizome from a grocery store last year. I planted it in a pot, about an inch or so deep, with drainage holes, with really good garden soil. I set it in a sunny place in my garden and kept it watered. It took almost 4 months to break surface, I thought it was dead/rotten, but it was no problem to let it set and treat it like it was alive. I know some native wild herb seeds can take YEARS to come up! Good thing! It grew really slowly, only reaching about a foot, and as it got cooler outside, I live in zone 4, I brought it indoors and set it on a sunny window sill. It stayed the same for a couple months, then died back. I figured it was dormant, and set it outside again in the same spot this spring after it warmed up. Took a long time to come up again, but is MUCH larger, with many more leaves. It's had an exposed portion of root, but think that's the way it wants to grow. Sticking my fingers carefully down around the root, I can feel it's growing nicely, careful to re-fill the finger holes! I don't intend on harvesting it at all for at least a couple more years, to hopefully ensure a decent harvest when I do without impairing the plant. Maybe the pot I'm using is helping? It's black plastic, about 6" deep, and about 15" around. Basically one of those black plastic "witches cauldrons" with holes punched in it that come out to stores around halloween time. LOL! I think the little legs on it to keep it off the direct ground might be good, too, and the fact it's shallow, and black to keep it warmer in the sun? All I know that for my zone it's doing well.