10-15 Days. Serrated Leaf Chrysanthemum Greens are ready to harvest in 10-15 days with tall, upright stems and light green leaves. These microgreens are ideal for a light, fresh, lettuce-like flavor. You can throw these into any leafy green mix for a tender burst of nutrients, or add them to any recipe that commonly uses lettuce or other salad greens. ~ 8,500 seeds per oz.