Micro Plants with Macro Taste

Photograph By
Cheryl Corson

Landscape designer Gary Hallewell tends his rooftop microgreens.

If you’re short on garden space but love growing edibles, microgreens may be just what you’ve been looking for. Ditto if you’re a gardener who also wants instant gratification. Nothing tasting this good takes less space, less time, or less effort.

Breaking the Rules

Capitol Hill garden designer Gary Hallewell enjoys sitting on his Eighth Street rooftop vegetable garden at the end of a long, hot workday, watching his potted beans, tomatoes, eggplants, and peppers grow. He even prefers this improvisational third-floor spot to the more precisely arranged brick and stone shade garden he designed on the ground floor below. A very long hose running from that space to the rooftop garden is the lifeline that connects the two. It is up here that Hallewell monitors his rapidly growing microgreen crop. Using a small pair of scissors, he snips tablespoons of micro-radishes, basil, cilantro, sorrel, and beets for me to try. They are the vegetable equivalent of Jell-O shooters; a little bit carries a big punch.

Hallewell’s microgreen setup is standard in many ways. He uses shallow, labelled plastic trays, a couple of inches deep, with a light soil mixed with vermiculite. Each tray contains a single plant variety. He broadcast-seeds the trays so that the plants grow in a big clumpy mass. With microgreens you don’t place one seed at a time onto the soil the way you might with crops you grow to full size and maturity.

Where Hallewell’s method differs from most microgreen growers is in exposure to sunlight. While most instructions say to provide the tender plants with ample shade, Hallewell takes a tough love approach that seems to work just fine. His trays are in full sun most of the day. He monitors moisture levels and waters them so they don’t dry out. No one told the plants that they can’t thrive in these conditions, and they do.

What Are Microgreens?

Microgreens have no legal definition, so let’s call them seedlings of any herb or vegetable plant that have grown to the point at which their first pair of true leaves just begins to appear. Microgreens are grown in soil, and are usually harvested just above the soil level with small scissors. The stem, embryonic cotyledon leaves (rhymes with Sweden), and tiny first pair of true leaves are eaten.

Typical microgreen plants include daikon radish, cilantro, basil, arugula, red cabbage, spinach, red amaranth, sorrel, mustard, radish and turnip, collards, and kale. Buckwheat is another favorite.

The farm-to-table microgreen cycle is faster than for any other crop. So is the seed-to-harvest cycle, which is measured in days rather than weeks. After germination a crop may be ready in as little as five days. This harvest is small and delicate, and you will want to eat it raw and add it to your food as close to serving as possible. Microgreens don’t store well or for long. This makes them an edible plant that offers the maximum benefit of growing it yourself. Home-grown tomatoes are wonderful, but these days you can purchase them at a farmers’ market or in season at Eastern Market for a fraction of the effort and expense of home grown. But only you can deliver microgreens to your dinner plate harvested five minutes before.

Good for You

Doesn’t it often seem as though plants that are good for us don’t receive the research funds they deserve? Fairly little research has been conducted on microgreens (compared to, say, GMO corn), however, one 2012 study was conducted just up the road at the Department of Nutrition and Food Science of the University of Maryland. The study is entitled “Assessment of Vitamin and Carotenoid Concentrations of Emerging Food Products: Edible Microgreens.” What did they discover?

The study found that, “in comparison with nutritional concentrations in mature leaves, the microgreen cotyledon leaves possessed higher nutritional densities.” It ranked various levels of vitamins and carotenoids (yellow, orange, and red foods) found in typical microgreen crops. Of the 25 crops studied, those with the highest nutritional value were red cabbage, cilantro, garnet amaranth, and green daikon radish. Some of the relative nutrient values are quite high compared to full-grown plants. While it may not be nearly as filling calorically, your microgreen snack may deliver serious nutrient value. You can read more about the study at http://pubs.acs.org/doi/abs/10.1021/jf300459b?prevSearch=microgreens&searchHistoryKey=&.

Sprouts Are Different

Large commercial sprout production has fallen out of favor in recent years. Harmful bacteria including E. coli, salmonella, and listeria have been found in commercial sprout harvests. In Germany and France 50 people died and thousands became ill from fenugreek sprouts in 2011. That year, others in the US became ill from salmonella found in alfalfa sprouts, and sprouts have quietly been disappearing from domestic menus. The problem seems to be in tainted seed and water. The same conditions that make sprouts grow well also favor bacterial growth.

Home-grown sprouts from organic seed, rinsed often with clean drinking water, carry far less risk than largescale commercial sprout production. You may find comfort knowing that our federal government is concerned about protecting us from bean sprouts. See the US Food and Drug Administration’s Sprout Safety Alliance, www.fda.gov/Food/GuidanceRegulation/FSMA/ucm293429.htm. Unlike sprouts, where the seed hull and roots are harvested, microgreens only utilize the tender, above-ground part of the plant, which makes them safer.

Grow Your Own

Seeds, a light soil mix, shallow trays, water, and sunlight are all you need to grow your own microgreens. Seeds, soil mixes, and trays are available at Frager’s Garden Center and at Ginkgo Gardens on the Hill. While some seed suppliers like Johnny’s Selected Seeds (www.johnnyseeds.com/) sell microgreen seed mixes, it’s perfectly fine to go with single-species trays. That way you can more easily discover which microgreens you prefer and which you find easiest to grow.

Keep in mind that these tender babies don’t want any more stress in their lives than you do, so keep moisture levels even and avoid baking them in full sun (unless your name is Gary Hallewell). When you have harvested all the microgreens from a single tray, simply mix up the soil and start all over again with new seeds. You can keep this going all season, and when you get the rhythm of it you’ll always have greens available.

How to Eat Them

Eat microgreens raw by the handful right out of the tray. Used as a garnish or a main salad ingredient, microgreens make a visually appealing and nutritionally rich addition to many recipes. You can also use them in smoothies. Here’s a recipe from Sweet Peas Urban Gardens in Raleigh, N.C., www.sweetpeasurbangardens.com/:

Green Smoothie

1/2 cup pineapple juice
1 tablespoon chia seeds
4 cups dark leafy greens; spinach works well
1 cucumber, diced
4 carrots, diced
1 frozen banana
1 orange, peeled
2 ounces mild microgreens such as collards, broccoli, or kale
Put chia seeds and pineapple juice in high-speed blender and blend until the seeds and juice form a gelatinous mixture. Add the spinach and then the rest of the ingredients and blend until smooth. Serves one.

I will sign off with some microgreen recipe eye candy: www.brit.co/microgreen-recipes/.  Bon appetit!

Microgreen trays contain beets, sorrel, mustard, and basil.
Technically, with developed mature leaves, this basil is more a baby green than a microgreen, but tastes just as good.
A close up look at Hallewell’s microgreen radishes.

Cheryl Corson is a licensed landscape architect, writer, and dirt gardener practicing on the Hill and beyond since 2003. For design assistance see: www.cherylcorson.com.

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