Buttercrunch is one of the most popular microgreens varieties. It's very easy to grow, germinates quickly, and has wonderful flavor. Give it a try! These greens should be harvested when the plants are 10 to 14 days old. They can be grown in moist paper towels (bleach-free), indoors in a soil mix, or in the outdoor garden. Baby greens in 25 days, 42 days to maturity.