Time to harvest depends on the plant and the growers preference. Some should be harvested at the cotyledon stage (broccoli, kale, cabbage) while others should grow until true leaves emerge (mustard, cilantro). The main reason is flavor. Most microgreens will be ready to harvest in 7 - 8 days, while some can take quite a bit longer. Each of our kits come with complete growing instructions and recommended times to harvest.