Kohlrabi Microgreens: Seeding Chart and Growing Guide

Kohlrabi microgreens are a quick, tidy brassica tray: the seed sprouts in about 36 hours at 72°F, and you can cut in roughly 10 to 15 days. Mississippi State Extension lists purple kohlrabi at 10 to 15 days, and Penn State’s yield table includes a purple cultivar. It is a friendly addition to a rack of trays that includes kale, mustard and red cabbage, because they all share a similar schedule. The fastest microgreens table shows how its timing compares. New to the method? How to grow microgreens covers the steps every variety shares.

Sowing kohlrabi microgreens

Sow kohlrabi thickly and evenly over a pre-moistened medium. Penn State and Maryland both advise a denser sowing for microgreens than for a crop grown to full size, and Penn State notes lower rates in summer than in winter and for larger seed than smaller seed. Check the seed packet for a starting rate and use the seed calculator if you are working with a different tray size.

For the medium, Penn State names peat-based mixes, coconut coir and fiber mats. Maryland suggests any lightweight soilless mix. Start clean for the best results: pick seed sold for microgreens or marked untreated (Clemson), use a shallow, food-suitable tray with drainage holes that you have washed with soap and water (Penn State), and use fresh water.

Cover and blackout

The cabbage family is quick to wake up: Maryland reports germination in about 36 hours at 72°F. Cover the tray with a second tray, lid or clear plastic to trap warmth and moisture (Clemson, Maryland), and keep seeds in the dark for a few days if you can (Penn State). Radish, kale and arugula in Utah State’s chart are covered for just 1 to 2 days, a helpful guide for the cabbage family. Uncover as soon as the stems are up and move to the light.

Light and watering

Natural window light or grow lights both work. Utah State’s chart for other varieties runs 18 hours of light and 6 of dark, Maryland suggests about 16 hours total, and Oregon State says a bright window works as well as fluorescent lights. Maryland recommends 70 to 75°F. Water from below by setting the tray in a shallow tub until the medium is damp, then draining it (Penn State). Keep a fan nearby or open a window occasionally so air moves over the dense stand (Maryland, Penn State). The harvest planner gives you the dates.

Harvest

Mississippi State lists purple kohlrabi at 10 to 15 days, grouped with mustard, kale, pac choi, red cabbage, kogane cabbage and arugula. Maryland’s general guide is 2 to 3 inches tall, 7 to 21 days after sowing, and Purdue and Utah State say to cut when the first true leaves appear. Cut just above the medium with clean, sharp scissors and leave the roots (Penn State). Seedlings do not regrow (Maryland, Oregon State), so the next tray gets fresh medium. Store the harvest in a clean plastic bag in the refrigerator (Clemson); Penn State reports 10 to 14 days at 41°F in the dark.

Flavor and color

Virginia Tech’s summary of flavor research describes brassica microgreens as more neutral than peppery arugula, so kohlrabi is a mild, versatile green. Penn State’s yield table lists Kohlrabi (Purple) and Mississippi State names purple kohlrabi, so a purple cultivar is available if you want a colorful tray. Pair it with red cabbage for a bright, two-tone mix.

How to use kohlrabi microgreens

• Scatter over slaw, grain bowls or noodle salads.
• Layer into sandwiches and wraps in place of lettuce.
• Top soups, roasted vegetables or a plate of eggs.
• Mix with kale for a savory salad base.
• Use as a colorful garnish for fish or grilled chicken.

For more ideas, see how to eat microgreens.

Trays and containers

Any shallow, clean, food-suitable tray with drainage holes works, as Penn State describes. Utah State lists standard 1020 trays, 10- or 20-row seed trays, pie tins and takeout containers, and Oregon State notes that drainage holes can be punched with a nail. Wash recycled containers with soap and water (Clemson).

Keep the supply going

Oregon State suggests starting just enough for the household to eat and planting more every few days. Maryland and Oregon State both note that a bright window or grow lights let you keep growing indoors through the year. Between rounds, refill with fresh medium, as Penn State recommends for each production cycle, and rinse the greens just before eating.

Plan your tray