Microgreens are super nutrient dense–you get all the vitamins and minerals of a mature plant in just a few leaves. They’re also delicious!
To keep your seeds growing well, mist them daily with a spray bottle. Water gently; heavy misting may crush the delicate seedlings. Keep the tray in a warm spot with bright sunlight. Harvest once the greens have a first set of true leaves and are a few inches tall.
Choose the Right Seeds
When you’re growing microgreens you can choose seeds from a variety of vegetables and herbs. Different seeds have different flavors and nutritional values. If you like a warm peppery taste try radish or pakchoi seeds.
Some seeds require soaking before planting. For example, sunflower and peas must be pre-soaked to maximize their germination rate. Some seeds should not be pre-soaked, such as kale and chard. The reason is that these seeds become mucilaginous, which means they form a gel when they come into contact with water. This makes it difficult to sprinkle evenly over your tray or soil.
Keep in mind that microgreens are ready to harvest when their first set of true leaves appear (as opposed to the cotyledons that initially sprout). Check them for readiness by looking at their height. When they are at the right height, cut them with scissors just above the soil line. They are then ready to use in soups, salads and sandwiches.
As with any growing medium microgreens can be grown in a variety of soil mixes. The ideal soil mix for microgreens is a seed starting mix or potting soil that is organic and contains compost for extra nutrients. Avoid using soil that has clay because it can be very dense and limit the root’s ability to absorb water and oxygen.
Another great soil alternative for microgreens is vermiculite or perlite. These are often added to other soil mixes to improve aeration and drainage. They are also mold resistant and sterile which makes them ideal for growing microgreens.
When planting in either type of soil be sure to mist the seeds and soil daily. This will help ensure the seeds are properly moistened and encourages strong root growth. The microgreens will be ready to harvest between seven and 14 days after sprouting. They will begin by forming two rounded embryonic leaves called cotyledons, and then form their first true leaf as they continue to grow taller under light.
Providing adequate light for microgreens is a critical step to success. It’s important to use a quality LED growing light with a color temperature of between 4,000K and 6,500K (or between warm white and daylight). Avoid lights with violet, blue or yellow tones as these can cause nutrient deficiencies in your microgreens.
Some microgreen seeds require a ‘blackout period’ during their initial germination, meaning they must be kept in complete darkness until they are ready to start photosynthesis. It’s important to know your seed varieties and whether they need this or not.
Check your microgreens daily and water if needed. Be careful not to saturate the soil as this can damage your emerging plants. Some growers recommend sprinkling your seeds lightly with a spray bottle to help them avoid being over-flooded with water. It’s also important to rotate your tray to ensure even exposure of all the plants to sunlight. This can be done daily, especially if you are using natural light from a window.
Microgreens need adequate water to keep the soil moist and encourage the germination of their seeds. They also need a moderate level of humidity.
When you water your microgreens, pour the water over the top of the potting mix until it is saturated. Then dump out any excess water. This method of watering avoids the risk of over-watering.
Use filtered or bottled water to ensure your microgreens aren’t exposed to any chemical residue from tap water. Water with a lower pH (closer to 6 than 7 or 8) is best for microgreens as it is less alkaline.
One way to tell if you need to water your microgreens is to simply pick up the tray and feel its weight. The more a tray weighs, the more it needs water. Occasionally tip the tray on its side to increase air flow around the plants and help the surface dry more quickly. If you are using a heat mat or your trays are placed underneath lights that emit heat, try to nestle the trays together, this will reduce the direct temperature and help your microgreens thrive.