Radish Microgreens: How to Grow Them in 8–12 Days

Radish microgreens are fast, bold and easy: sow 42 g of seed per 10×20 inch tray, skip the soak, keep it covered for only 1 to 2 days, and you can be cutting a nutty, spicy harvest in about 8 to 12 days. Utah State Extension lists that recipe, and Virginia Tech and Mississippi State report even quicker harvests, from 6 to 10 days. For a spicy flavor with so little waiting, radish is hard to beat. It is also one of the picks in microgreens for beginners, and the fastest microgreens table shows how it compares on speed. New to the method? How to grow microgreens covers the steps every variety shares.

Sowing radish microgreens

Utah State’s chart lists 42 g of radish seed for a 10×20 inch tray, with no presoak. Mississippi State gives the same job in tablespoons: 2 to 3 tablespoons for that tray size. Scatter the seed thickly and evenly over a pre-moistened medium, as Penn State and Maryland advise for all microgreens. The seed calculator scales the gram figure to your tray size.

Radish takes happily to a mat. Virginia Tech lists hemp and burlap grow mats for radish microgreens, and Penn State names peat-based mixes, coconut coir and fiber mats as the common media. A good start makes the whole tray easier: seed labeled for microgreens or untreated (Clemson), a tray washed with soap and water, and fresh water for each watering.

Cover and blackout

Radish needs the shortest covered start in Utah State’s chart, just 1 to 2 days. The cabbage family germinates quickly, about 36 hours at 72°F according to Maryland, so check the tray after a day. Cover with a second tray, a clear lid or plastic to trap warmth and moisture (Clemson, Maryland), then move to the light when the sprouts are up.

Light and watering

Natural window light or grow lights both work. Utah State suggests 18 hours of light and 6 hours of dark, Maryland about 16 hours total, and Oregon State says a bright window does the job as well as fluorescent lights. Maryland recommends 70 to 75°F. Water from the bottom by setting the tray in a shallow tub until the medium is damp (Penn State) and keep the air moving with a gentle fan (Maryland). The harvest planner turns your sow date into uncover and cut dates.

Harvest

Utah State lists 8 to 12 days, Virginia Tech 6 to 10 days and Mississippi State 7 to 10 days, grouped with pea shoots as the quickest crops in its list. Maryland’s general size guide is 2 to 3 inches tall, 7 to 21 days after sowing. Cut just above the medium with clean, sharp scissors (Penn State). Radish microgreens do not regrow after cutting (Maryland, Oregon State), so the next tray gets fresh medium. For a steady supply, Oregon State suggests starting just enough for the household and sowing more every few days. Cold, dark storage at 41°F extends shelf life to 10 to 14 days (Penn State).

Arugula is the quickest variety in Utah State’s chart, with a 6 to 8 day listing.

Flavor and color

Utah State lists radish as nutty and spicy, and Oregon State recommends radish and mustard for a spicy kick. Both Utah State and Penn State list a purple radish cultivar, so a colorful tray is possible if you buy seed for it. Fresh radish microgreens add a peppery punch to anything that is plain.

How to use radish microgreens

• Scatter over tacos, noodle bowls or a fried egg for a peppery finish.
• Layer into sandwiches and wraps for a spicy crunch.
• Toss with sweeter pea shoots to balance the heat.
• Add to a cold salad of cucumber or avocado.
• Use as a garnish on soup just before serving.

Keep the supply going

Because a radish tray is ready so quickly, it suits succession planting: Oregon State suggests starting just enough for the household to eat and planting more every few days, so there is always a tray coming along. Maryland and Oregon State both note that a bright window or grow lights let you keep growing indoors through the year. Between rounds, empty the tray, wash it with soap and water and refill with fresh medium, which Penn State recommends for each production cycle. Store the cut greens in a clean plastic bag in the refrigerator (Clemson) and rinse them just before eating, as Penn State advises.

What’s in it

See microgreens nutrition for how these figures fit the wider USDA studies.

Plan your tray