Instructions for Growing Microgreens: Starting Seeds in Soil

In a fresh cut form, microgreens can offer 50 times more nutrition at the first leaf stage when compared to the mature vegetable. Maintaining a year round supply is easy and fun using minimal light and room temperatures. Learn how to measure seeds for your container size, prepare the microgreen soil, and maintain seedlings for the 7 to 10 day growing cycle.

Get ready to sprout the seeds

Measure out desired amount of seeds according to package directions for the size of growing container you are using. Since seed size and germination times can vary according to the microgreen variety, refer to the recommendations on the seed package or the chart below.

These are seed quantity guidelines for most small microgreen seed such as broccoli, cabbage, kale, kohlrabi, etc. Use a  little less for gel type seeds such as basil, mustard and arugula, and a little more for larger seeds such as radish. Large seeds such as sunflower, pea, and wheatgrass seeds do not apply to this table. Use shallow growing containers 1 inch to 2 inches high for growing small leaf microgreens.

Dry Seed Chart For Microgreens

Container Size	Quantity of Seed	Amount of Soil
4" to 5" square	1 teaspoon (4 grams)	1.5 cups
7" to 8" round	2 teaspoons ( 7 grams)	2 cups
9" round	1 Tablespoon (9 grams)	3 cups
10"x 10" square (half flat)	2-1/2 Tablespoons (0.75 ounce or 22 grams)	6 cups
10" x 20" rectangle (nursery flat)	1.25 ounces ( 36 grams)	12 cups

* There are approximately 4 cups per quart of soil.

* Figures were derived using a level measuring device. For a less condensed growing environment, use smaller amounts of seed. Microgreens that do not have a crowded growing environment may get leggy and topple over, making cutting difficult, so be generous when spreading seeds but avoid overlapping.

Should you pre-soak microgreen seed?

Most seeds can be soaked in water overnight to jump-start the sprouting process, but this is not required. Seeds can easily be sowed dry. Check the seed package for recommendations.

Larger seeds such as sunflower, wheatgrass, and peas will benefit from pre-soaking. (See blog article Pre-soaking Microgreen Seed). If seeds are pre-soaked in water before planting, rinse seeds with fresh water and drain off any excess water using a small strainer.

Get ready to plant the seeds

Measure out soil mixture and place in growing dish.  Lightly pat soil so surface is even.

Mist soil generously with water from a spray bottle or a kitchen faucet spray.

Spread wet seeds evenly over soil.  Seeds should completely cover soil to allow for dense growth, but avoid overlapping seeds. If stems of growing microgreens are not densely packed, stems will topple over while watering and this can cause rotting or mold issues to develop. Pre-soaked seeds will tend to clump so use a light touch to spread around the container so you don't break off any sprout tips that have popped out.

After seeds are spread around soil, mist generously with water again to thoroughly saturate seeds.

It is not necessary to cover seed with topsoil. This prevents dirt from getting on the tender leaves. Some seeds that dry out quickly such as cabbage and kale will benefit from a very thin layer of topsoil to maintain moisture while the sprouting process is taking place.

Growing microgreens is a trial and error process. It will be easy to develop a consistent growing process once you discover what works best for the type of microgreen seed you select and the environmental conditions for the growing area.

Measure out soil according to guidelines for the size of growing dish you have selected.

Measure out amount of microgreen seed according to the size of your growing container.

Mist soil with a spray bottle or sink sprayer before spreading microgreen seed.

Gently spread wet seeds or sprinkle dry seeds evenly around soil.

Lightly mist spread microgreen seeds again.

The Sprouting Phase

Cover container with domed cover or a light towel, napkin or paper towel for 2-3 days. While seeds are germinating, put container in a warm area or on a heated grow mat. Room temperatures of 65⁰-70⁰ are ideal for germination.

At the germination phase, light is not necessary. Check on seeds twice a day and mist with a spray bottle to keep the soil moist while the seeds germinate.  After 2-3 days, tiny sprouts will emerge from the seed.

After 3 to 5 days, when the sprouted seeds form their first leaves, remove any covering and expose microgreens to light. Continue misting daily with water, so soil remains moist.
 
Leaves may look yellow colored, but after a day or two with light, they will turn to their appropriate color.

At this stage, growing container can be placed under florescent grow lights or stored near a window. If the new sprouts begin to lean toward a light source, either rotate dish or move to a place with brighter light.
 
Air circulation is necessary to prevent mold and a small fan or ceiling fan blowing near the plant works well to move air. An open window also provides air circulation.

Microgreens will be ready to eat in about 7-10 days after their first leaves have fully formed. For best flavor and nutrition, harvest before the second leaf begins to form.

Cover seeded microgreen growing dish with a napkin, paper town, or other light covering to keep germinating seeds in the dark and prevent seeds from drying out.

When microgreens start to develop their first leaves, remove covering and transfer growing container to a light source.

Most microgreens will be ready to harvest after 7-10 growing days. Wait until the first leaf is fully developed but harvest before second leaf begins forming.

How to harvest microgreens

When ready to use, cut microgreens with scissors or a sharp knife just above soil. If you grew a large dish of microgreens, cut only the amount needed at one time and let microgreens continue to grow, keeping soil moist. The crowded growing environment will not allow for much more leaf growth, so leaving a partially cut dish of microgreens for another day or two should be okay. However, if leaves begin to turn yellow, its time to harvest the rest of the batch.

After cutting, microgreens can be refrigerated in a closed container, but should be used within 3-5 days for optimal flavor.

A frequent question that I hear at our market booth is how you can wash microgreens. That question is answered in another blog article, so check out How To Wash Microgreens.

Seeding Cycle

To keep an ongoing fresh cycle of microgreens, repeat microgreen seeding in a second growing dish in about 5-7 days to keep fresh microgreens on hand. When one dish of microgreens is used up, wash out dish and reuse for another seeding. Most microgreens will not grow back after cutting, so reseeding is necessary.

Harvest microgreens using scissors and cut just above the soil.

Store cut microgreens in a covered container in the refrigerator.

Start with a test batch

For first-time microgreen growers, I recommend you start with a 4" or 5" diameter container as a test before moving on to larger containers such as a nursery flat. For a novice to sacrifice an ounce of microgreen seed and then have unsuccessful results can be a costly and discourage potential indoor gardeners from this fun and nutritional hobby. Start with small batches and increase the growing container size as you master the process.