We grow 21 different types of microgreens indoors at our farm in the West Chicago/Wyoming area of Detroit. Many of our microgreens are sold individually and some are used exclusively in our mixes. Some grow quickly and are ready to harvest within 9 days of sowing. Others take a bit longer, as much as 21-24 days. They all start out germinating in trays for a period of time, followed by a brief period covered where they are not exposed to light (blackout period). They are then uncovered and exposed to light for 16 hours a day. When first taken out of blackout, they don’t have any chlorophyll and are pale yellow. After being exposed to light, the chlorophyll develops and they green-up.