Microgreens

Mid-winter can be a tough time for growing fresh greens at home if you live in an area with cold temperatures, ice, and snow. But microgreens are one way to get delicious, healthful greens at any time of year

Red cabbage microgreens (Peggy Greb)

What are microgreens?

Microgreens are halfway between sprouts and baby greens in the plant development process. Where sprouts are germinated (or partially germinated) seeds without any real leaf development, and baby greens are miniature versions of adult plants, microgreens are harvested just after the cotyledons and first true leaves have appeared, usually when they are two or three inches tall. They are a fast-growing way to add bright freshness to your diet, even in the middle of winter.

While they may be small, microgreens can contain 4–40 times the level of nutrients found in their adult counterparts, according to the USDA Agricultural Research Service and the University of Maryland. In that study, broccoli microgreens were found to contain sulforaphane, known to block DNA mutations that can lead to cancer, as well as compounds that neutralize toxins and reduce inflammation. These little plants are nutritional powerhouses and easier to digest than full-sized greens.

Technicians harvesting different types of microgreens for shelf-life studies and nutrient analyses (Peggy Greb)

What are popular microgreens?

Nearly all salad greens, vegetables, herbs, and edible flowers can be grown as microgreens. Below is an exhaustive list of edible plants that can be grown as microgreens, grouped by plant family. Some of them may surprise you!

• Beet Family: amaranth, beets, Malabar spinach, New Zealand spinach, quinoa, spinach, Swiss chard
• Cabbage Family: arugula, bok choi, cabbage, cauliflower, collard greens, kale, kohlrabi, komatsuna, mizuna, mustard, radish
• Carrot Family: anise, caraway, carrot, celery, chervil, cumin, dill, fennel, parsley, parsnip
• Grass Family: barley, corn (sweet), millet, oats, rye, sorghum, wheat
• Legumes: Adzuki bean, alfalfa, chickpea, clover, fava bean, fenugreek, lentil, mung bean, pea shoots
• Mint Family: basil, bee balm, lemon balm, marjoram, mint, oregano, sage, savory, shish, thyme
• Onion Family: chives, garlic chives, leek, onion, scallion
• Squash Family: cucumber, melons, squash (summer and winter)
• Sunflower Family: calendula, chicory, chrysanthemum*, cornflower, endive, escarole, frisée, lettuces, marigold*, radicchio, sunflower, tithonia*
• Various Families: buckwheat, dianthus, johnny-jump-up, miner’s lettuce, nasturtium, purslane, sorrel, viola

NOTE: Plants with an asterisk (*) have both edible and non-edible varieties. It is important to know which ones you are working with, so do your homework!

Did you know that, unlike most microgreens, corn seeds grown in the dark are sweet, while those exposed to light taste bitter. Weird, eh?

And, there are some plants you should never grow as microgreens.

This group is the nightshade family. As much as we love the eggplants, peppers, potatoes, and tomatoes we grow, those stems and leaves are toxic and should not be eaten.

How to grow microgreens

Your microgreens can easily be grown on a windowsill, outside, or in a greenhouse. They can also be grown hydroponically, but do not fertilize your microgreens. They don’t need it, and it can make them taste bad.

Start with shallow trays, at least half an inch deep, with drainage holes. You can also use ceramic planter saucers.  If you are reusing a container, sterilize it first to prevent the spread of disease.

Microgreens are gregarious plants and prefer not to be grown in the solitary confinement of egg cartons or individual pots.

Next, add a shallow layer of potting soil or other growing medium, such as peat moss or coconut coir.
Microgreens are an excellent way to use up those half-filled seed packets from the previous growing season. Just be sure to use certified pest- and disease-free seeds.

You can either scatter the seeds over the top of the soil or plant them in tidy rows, if you have that much patience. Press the seeds gently into the soil to ensure good contact. Mist the seeds regularly until they germinate, keeping the soil moist but not soggy. And watch for mold and fungal disease.
Your microgreens will grow best with plenty of sunlight.

Problems with growing microgreens

The biggest problem associated with growing micrograms is moisture. The seeds need that  moisture to germinate, but all that wetness can lead to fungal diseases, such as damping off. This is especially common when temperatures are above 68°F (20°C).

Ensuring good drainage and allowing the surfaces of leaves and stems to dry between waterings can help prevent disease. If necessary, you may want to place a small fan near your micrograms. This will help them dry, and it will also strengthen their little stems (thigmomorphogenesis).

If you want a pro’s perspective, you can track down the FDA’s Guidance for Industry: Reducing Microbial Food Safety Hazards for Sprouted Seeds (FDA 1999).

Harvesting microgreens

Your microgreens are ready to harvest in as little as 10 to 25 days, depending on the species.

Microgreens are harvested when  they are 2 or 3 inches tall. The cotyledons (seed leaves) will be fully open, and the first two or three true leaves may be partially or fully developed. Microgreens are cut, often with scissors, just above the soil line. The remaining root system will slowly decompose, providing nutrients for important soil microorganisms and neighboring plants.

As you harvest your microgreens, simply add more seeds to the soil to maintain a sustainable supply of delicious microgreens.

Microgreens can add color, texture, flavor, and good nutrition to your omelettes, salads, sandwiches, and smoothies, and they can make your windowsill far more productive.