In the Garden: Microgreens keep harvests going during winter

Who says you can’t grow vegetables year-round in the Inland Northwest? While it’s true we have a frost-free season of about 120 days, that doesn’t mean there aren’t options for continuing to put fresh, healthy produce on your table – even in January.

Over the past few years, I’ve been growing cold-tolerant vegetable crops in a hoop house in my garden. Kale, corn salad (mache), claytonia (miner’s lettuce) and spinach have performed well for me. That is, until about the middle of last winter when we alternated between bitterly cold temperatures and heavy snowstorms. Even my super-hardy salad greens didn’t want anything to do with that.

Fortunately, I had started growing microgreens indoors in the fall and those got us through the entire winter without my having to buy a single head of lettuce. Intrigued?

Put simply, producing microgreens involves thickly sowing seeds in flats and harvesting them while they are young seedlings with some true (mature) leaves. They can be grown any time of the year – indoors or out – but for this region, indoors during the colder months of the year is a perfect way to supplement the food I grow and preserve during our regular garden season.

The best part of growing and eating microgreens is that they are packed with nutrients. A joint study done by the University of Maryland College of Agriculture and the U.S. Department of Agriculture determined that microgreens contain anywhere from four to 40 times more nutrients than the mature form of the plants.

I fill seedling flats with 2 inches of seed-starting mix or organic potting mix. Once the mix has been moistened and compressed a bit, I sprinkle seeds over the top, cover the flats with a clear plastic dome lid and place them under grow lights. A sunny windowsill is another option.

Most seeds germinate quickly – at which time you remove the clear lid – and the resulting plants are usually ready to be harvested within 10 to 14 days. Harvesting involves using scissors or a knife and essentially mowing down the seedlings above the surface of the soil.

Choosing seeds to grow as microgreens is half the fun. Buying them in bulk quantities keeps it economical. I went to the sproutpeople.org website to study their options, but you can also find seeds locally at Northwest Seed & Pet as well as online sources such as Johnny’s Selected Seeds (johnnyseeds.com), Eden Brothers (edenbrothers.com) and High Mowing Organic Seeds (highmowingseeds.com).

Last winter, I grew sunflowers, brassica mixes (cabbage family crops), lettuce, peas and beets and everything was delicious. In fact, it was so simple, I’ve been wondering why I haven’t tried it sooner.

Here are a few things I’ve learned:

Most types of seeds do not need to be covered with seed-starting mix, so I just sprinkled the seeds thickly onto the mix and pressed them into it. The only seeds that seemed to grow better by being covered were the peas.

It’s possible to use the cut-and-come-again harvesting method for lettuce to get multiple pickings from a single sowing.

Sunflower seedlings should be harvested before they get their true leaves, which are hairy and bitter.

Harvested microgreens last best when rinsed with water, gently tossed in a salad spinner and stored in the refrigerator.

A good reference guide to growing microgreens is “Microgreens: How to Grow Nature’s Own Superfood” (Firefly Books, 120 pp., $19.95) by Fionna Hill.

Learn more about microgreens in this week’s “Everyone Can Grow A Garden” video at youtube.com/c/susansinthegarden.