Microgreens began showing up on chefs’ menus as early as the 1980s in San Francisco. In Southern California, microgreens have been grown since about the mid‑90s. There were initially few varieties offered; those available were: arugula, basil, beets, kale, cilantro and a colorful mixture of those called “Rainbow Mix”. Having spread eastward from California, they are now being grown in most areas of the United States, with an increasing number of varieties. Today, the U.S. industry for microgreens consists of a variety of seed companies and growers.
Microgreens have three basic parts: a central stem, cotyledon leaf or leaves, and typically the first pair of very young true leaves. They vary in size depending upon the specific variety grown, with the typical size being 1 to 1.5 in (25 to 38 mm) in total length. When the green grows beyond this size, it should no longer be considered a microgreen. Larger sizes have been called petite greens. The average crop-time for fast-growing microgreens, such as many brassicas, is 10–14 days from seeding to harvest. Slower growing microgreens, such as beets, chard, and many herbs, may take 16-25 days to reach harvestable size. Both baby greens and microgreens lack any legal definition. The terms “baby greens” and “microgreens” are marketing terms used to describe their respective categories. Sprouts are germinated seeds and are typically consumed as an entire plant (root, seed, and shoot), depending on the species.
For example, sprouts from almond, pumpkin, and peanut reportedly have a preferred flavor when harvested prior to root development. Sprouts are legally defined, and have additional regulations concerning their production and marketing due to their relatively high risk of microbial contamination compared to other greens. Growers interested in producing sprouts for sale need to be aware of the risks and precautions summarized in the FDA publication Guidance for Industry: Reducing Microbial Food Safety Hazards for Sprouted Seeds (FDA 1999).