Introduction to Microgreens

To understand microgreens, one must first understand the fundamental biology of plant development. Microgreens are not a specific class or species of plant; rather, they are a specific physiological stage in a plant's life cycle. They are the young, tender, and edible greens produced from the seeds of various vegetables, herbs, and even some grains. Botanically speaking, a microgreen represents the transitional phase between a germinated seed and a mature, photosynthetic plant. When a seed is planted and exposed to the correct matrix of moisture, oxygen, and temperature, it breaks dormancy. The radical (embryonic root) emerges first to anchor the plant and absorb water. Shortly after, the hypocotyl (embryonic stem) pushes upward through the growing medium, carrying with it the cotyledons. Cotyledons, often referred to as "seed leaves," are the embryonic first leaves of a seedling. In dicotyledonous plants (dicots, which make up the vast majority of microgreens like radish, broccoli, and sunflower), there are two cotyledons. These structures are pre-formed inside the seed and are packed with the stored energy and nutrients the plant needs to survive its initial growth phase before it can establish a robust root system and begin photosynthesis. A microgreen is traditionally harvested when these cotyledons have fully expanded and are actively photosynthesizing, but right before or just as the first "true leaves" begin to emerge from the apical meristem (the growing tip).