Microgreens are big on flavor

Microgreens are young, tender, edible crops that are harvested as seedlings. These tiny plants are grown to the first true leaf stage. Microgreens are used to enhance the color, texture or flavor of salads, or to garnish a wide variety of main dishes.

Certain crops of microgreens germinate easily and grow quickly. These include cabbage, beet, kale, kohlrabi, mizuna, mustard, radish, swiss chard, and amaranth. Soaking some seeds prior to sowing, such as beets, helps facilitate germination.

Growers should evaluate various crop varieties to determine their value as microgreens. Many seed companies are very knowledgeable about the crops and varieties to grow, and a number of them offer organic seed.

Microgreens are mainly targeted toward restaurants or upscale grocery stores. Prices range from $30 to $50 per pound. The product is packaged in plastic clamshell containers that are typically 4–8 ounces but can be sold in 1-pound containers.

Production
Microgreens can be grown in a standard, sterile, loose, soilless germinating media. Many mixes have been used successfully with peat, vermiculite, perlite, coconut fiber, and others. Partially fill a tray with the media of choice to a depth of ½ inch to 1-2 inches, depending on irrigation programs. Overhead mist irrigation is generally used only through the germination stage in these media systems. After germination, trays should be subirrigated to avoid excess moisture in the plant canopy.

An alternative production system uses one of several materials as a mat or lining to be placed in the bottom of a tray or longer trough. These materials are fiberlike and provide an excellent seeding bed. Materials may include burlap or a food-grade plastic specifically designed for microgreens.

Most crops require little or no fertilizer, as the seed provides adequate nutrition for the young crop. Some longer-growing microgreen crops, such as micro carrot, dill, and celery, may benefit from a light fertilization applied to the tray bottom. Some of the faster-growing greens, such as mustard cress and chard, may also benefit from a light fertilization because they germinate quickly and exhaust their self-contained nutrient supply quickly. Light fertilization is best achieved by floating each tray of microgreens for 30 seconds in a prepared nutrient solution of approximately 80 ppm nitrogen.

Microgreens are ready for harvest when they reach the first true leaf stage, usually at about 2 inches tall. Time from seeding to harvest can vary greatly by crop from 7 to 21 days.

Pest management
The microgreen high density cropping system provides the ideal environment for the development of seedling diseases. These young plants are particularly vulnerable to Pythium and Phytophthora damping-off; however, Sclerotinia and Rhizoctonia diseases may pose a problem on some hosts. Sanitation, proper plant spacing, and good cultural practices will be necessary to prevent these diseases from gaining a foothold. In addition, the use of a sterile soilless media, which is required for success, should reduce any potential disease problems.

Potential insect problems include aphids and thrips.

Sources: University of Kentucky Cooperative Extension and University of Florida IFAS Extension

Did you know?
Microgreens have higher nutrient densities than mature leaves.