Choosing a Container
When selecting containers for growing your micro greens, select containers that are well-drained and will not promote fungus or rot in the bottom of your containers. Additionally, select containers composed of safe, non-toxic materials. For better drainage, you can line the bottom of your container with rocks to prevent the bottom of your container from becoming soggy.
Selecting a Soil
It is important to select a high-quality, sterilized planting medium for growing microgreens. Blends composed of organic constituents and growth aid such as compost, earthworm casings, kelp, bat guano and other natural will promote higher germination rates, faster & more consistent growth, and stronger, more nutrient dense microgreens. Avoid using soil from your backyard as it is likely too high in clay content, unsterilized and will not provide the conditions for optimum growth.
Once you have obtained your seeds, containers, and growing medium, you are ready to begin.
The first step will be to soak your seeds, especially larger seeds or grains grown for microgreens. This will help to soften up the protective seed coat and promote faster and higher germination rates. For most seeds, soaking overnight for around 6-8 hours should be adequate. For larger seeds, especially larger seeds such as wheat berries or sunflower, a few additional hours is recommended.
Prepare your containers for seeds by adding growing medium to containers and pressing soil into containers. Ideally, the soil should be dense enough to provide dense nutrition and proper stability for your growing plants, but not so dense that the soil will not readily absorb water or discourage root penetration.
You are now ready to sow your seeds. The size of the seed will generally determine how deeply seeds can be sown. A good general rule of thumb is to sow seeds twice the thickness of the seed deep, or three time the diameter at the thickest point. Alternately, you may wish to use unbleached paper or cloth towels instead of covering seeds with soil. This can be especially helpful with small seeds. This technique offers convenience and requires less soil than conventional sowing.
Once seeds are sown or covered with towel, it is very important that the seeds and growing medium be kept moist but not soggy, as this can promote rot or other damaging conditions. This is especially important while you wait for seeds to germinate. Do not allow your growing medium to dry out, as this can cause rapid damage to young starts.
Depending upon conditions, you may find it helpful to use heat mats under your flats (if using flats and sowing in a cool environment). This will help to provide ideal conditions for germination. Additionally, covering your seeds with plastic wrap, or matching plastic cover in the case of flats, will help to retain the essential moisture necessary for germination.
As seeds begin to germinate, typically 2-5 days for most seeds, continue to keep soil moist. Remove covering from seeds once most of the seeds have germinated and have begun to grow taller. As plants grow and mature, water needs decrease slightly. As your plants continue to grow, you can promote faster growth with increased exposure to light, preferably natural sunlight. Select a warm and sunny location, and be sure to water regularly.
Microgreens can be harvested once plants begin to develop their first set of leaves (cotyledons)and have progressed beyond the sprout stage. Like sprouts, they are rich in vitamin and enzyme content, but with the added benefit of developing root systems which allow for the uptake of trace minerals from the soil. Most microgreen varieties can be harvested within one to three weeks, and like sprouts, make a great choice for those seeking fresh, nutritious food with limited space.
Many microgreens can be harvested within 2-3 weeks after germination. Try to harvest in the mornings before the heat of the day sets in. Crops harvested at midday or early in the afternoon are more susceptible to wilting and cannot be stored as long. A sharp scissors with long blades is ideal as it will minimize bruising and other unnecessary damage. To harvest, take plants approximately 1" from the surface of the soil, depending on preferences.
If less stem is preferred, cut higher up the stem.
After harvest, microgreens can be eaten immediately, or gently washed and refrigerated for use within a few days.
Seeds can be saved from any type of microgreen, if the plant is allowed to bolt to seed. The seed pods can typically be allowed to dry out on the plant. Rubbing separates the plumes and chaff from the seeds. When completely dry, shake the flower stems in the bag. Rub the seed heads between your hands to release more seeds. Put the seed through a fine mesh sieve that allows the seeds through but retains the chaff and plumes; this will give relatively clean seed. Winnowing is difficult because seeds and chaff are about the same size and weight. For extra cleaning use reverse screening, with a smaller mesh that retains the seed but lets small pieces or chaff and plume through. The dust produced during cleaning causes irritation to the lungs and eyes. If cleaning large amounts use a mask and goggles or clean outdoors.
For seed saving suggestions on specific varieties, visit our other growing guides.