I am interested in using more microgreens and would like some advice on how to grow them at home.
— Rissi Melecio, Highland Park
We could all use some tips about improving our diets, and microgreens are a great place to start. Microgreens are the sprouted seeds of edible vegetables and herbs grown in small, shallow containers. Routinely used by fine dining chefs, they have intense flavors and add visual appeal to dishes. They are also good for you, with a high concentration of nutrients. They are difficult to find in stores and expensive to buy — but easy to grow indoors year-round.
Start with a small, shallow container such as a seed flat or repurpose a plastic take-out container. You only need about an inch (2 inches maximum) of a well-drained growing medium designed for containers. The container you choose must have drainage holes. The soil must be kept moist throughout the process. Moisten the growing medium before filling your containers. To keep the medium consistently moist, use seed trays with water wells. Otherwise, check your containers daily and mist them when the soil begins to look dry. Very small seeds like lettuce can be sprinkled on the surface of the growing medium, misted and covered with a clear plastic lid until the seeds sprout. Larger seeds need to be sown ¼- to 1/8-inch deep. Sift the growing medium over the seeds once the seeds are spread on the surface. Place the container where the temperature is at least 60 degrees Fahrenheit. Consider using a heat mat for starting seeds to speed up and improve the germination rate. Microgreens do not need fertilizer. A water mister is handy for moistening the soil without dislodging the seeds. Place a clear lid or plastic wrap that transmits light over the container to increase humidity until the seeds sprout. Ventilate covered seeds daily, especially in bright conditions.
You can get consistently good results by growing the microgreens under grow lights for 12 to 14 hours a day. A fluorescent fixture hung on a chain works best, as you can adjust the level to keep the light at the optimum 8 to 12 inches above the seedlings. A kitchen window is another option, but inconsistent temperatures due to drafts and the quality and quantity of sunlight in the winter make for inconsistent results. South and west exposures work best for winter and north and east for summer. Experiment to see what works best for you as you find the best bright, indirect light.
Most microgreens are harvested after seven to fourteen days when they are 1 to 3 inches tall at the first true leaf stage of development. Some are harvested at the seed leaf (cotyledon) stage, which is when the first set of leaves emerges at germination. The true leaves are the second set that develops. These leaves look more like mature plant leaves. Use a pair of kitchen shears to cut off the seedlings at the growing medium level as you need them. The microgreens will last three or four days in a sealed container in the refrigerator. It is not necessary to wash the greens if you use an organic growing mix and clean scissors for harvesting. The plants grow for a short period of time and in a controlled environment, so there should rarely be issues with dust or soil clinging to the greens.
Seed companies have microgreen mixes and varieties available for purchase. A wide variety of plants work as microgreens, including beet, radish, celery, basil, dill, lettuce, arugula, chives and cilantro. Plants in the Brassica genus are great ‘starter’ microgreens. Check the seed packet for growing tips, as some greens are more finicky than others and need special attention. Arugula seeds, for example, do better if they are sown sparsely rather than crowded together. Germination rates that are above 95% increase your likelihood of success.
For more plant advice, contact the Plant Information Service at the Chicago Botanic Garden at plantinfo@chicagobotanic.org. Tim Johnson is senior director of horticulture at the Chicago Botanic Garden.
