These teensy microgreen seedlings are grown for harvest at a tender stage and are perfect for a windowsill garden. They’re ready for harvest and can have their stems snipped after only two to three weeks of growing. If left to grow, microgreens become young seedlings and then full-fledged plants. To grow microgreens indoors, you’ll need potting mix and bright light. Flavors range from intense, like a full-grown plant, to subtle.