Q: I like to add microgreens to salads. I see that the co-op offers packets of seeds so you can grow your own. Can you offer me some tips?

A: Microgreens are tiny immature versions of vegetables and herbs that can be harvested within 7 to 14 days after they germinate. They are nutritious and provide a fresh homegrown harvest even during winter months. They can be used in salads, to top soup, in a smoothie, with eggs or added to a sandwich. They are expensive to buy and inexpensive to grow.

Micro greens can be harvested within 7 to 14 days after they germinate. (Beth Wiemken / For the News Tribune)
Micro greens can be harvested within 7 to 14 days after they germinate. (Beth Wiemken / For the News Tribune)

To grow fresh greens, you will need soil, seeds, a container and a spray bottle.

The soil should be a sterile soilless mix that should first be moistened so that when you squeeze a handful, it will clump together. No need for fertilizer.

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To start on your micro-green-growing journey, you might want to try seeds that germinate within 3-5 days such as arugula, broccoli, peas or mustard. Other seeds you might try include basil, kale, beet, purple cabbage, chard, radish and sunflower. Look for seeds that have not been treated with fungicide. The most economical way to purchase your seeds is to buy them in bulk, by the pound, rather than just a small packet. You can get them at some local shops or order them from a garden supply store.

Microgreens can be grown inexpensively at home with a few simple supplies. (Beth Wiemken / For the News Tribune)
Microgreens can be grown inexpensively at home with a few simple supplies. (Beth Wiemken / For the News Tribune)

Your container needs to have drain holes, and it is best that it be wider than it is deep. If you want to start small, just recycle a takeout container or a plastic strawberry or blueberry container that has been sterilized in a 10 percent bleach solution. For a larger crop, use a standard 20x10-inch black plastic tray. Fill the container with 1-2 inches of your moist soilless mix and with the back of your hand, smooth and flatten the soil. Be careful not to compact the soil.

Densely scatter your seeds, about 10-12 small seeds per square inch or 6-8 larger seeds per square inch. Gently press the seeds so they are in good contact with the soil and spritz with a fine spray to “seat” them. Cover the seeds either with a light dusting of soil, a damp paper towel or a plastic lid that fits the container. At this stage, the seeds do not need light, but need to be in a space that is at least 50 to 60 degrees. You will need to check every day to be certain that the surface of the soil does not dry out. You may need to spray daily to keep seeds moist.

After the seeds germinate, they will need at least four hours of medium-bright light. Do not place your containers too close to cold windows. You will need to remain attentive to their moisture needs. Stick your finger in a corner of the soil to be certain all the soil is moist. Most likely, you will need to water daily. You could water from the bottom by setting your container in water for a few minutes. Do not let it sit in a pool of water.

Within about 5 to 7 days after germination, you'll be ready to harvest your crop. Use a sharp scissors and cut above the soil line. If the greens need to be rinsed, use cool water. These nutrient-rich greens are tender, so be gentle. You can then enjoy them or refrigerate them in an airtight container for up to 3-4 days.

If your greens are pale in color or leggy, you might not have enough natural light and will need to try another location or invest in a grow light.

Written by U of M Extension Master Gardeners in St. Louis County. Send questions to features@duluthnews.com.

This story originally used the wrong unit to explain how to buy seeds at a low price. It was updated at 4:20 p.m. March 1. The News Tribune regrets the error.