Short answer: soak 15 to 20 g of purple kohlrabi seed for 1 to 2 hours. Sow it evenly on a 10 × 20 inch tray of moist soil, cover it, and keep it dark for 2 to 3 days. Uncover, give bright light for the best purple colour, and water from below. Cut at 8 to 10 days.
What is purple kohlrabi?
Kohlrabi (Brassica oleracea var. gongylodes) is a cabbage-family vegetable grown for its round, swollen stem. As a microgreen, purple kohlrabi grows purple stems and green leaves with a mild, sweet taste. Sprouting.com gives it 5 days as sprouts and 8 to 10 as microgreens.1
How to grow kohlrabi microgreens
- Day0
Soak
Soak the seed for 1 to 2 hours. Drain.
- Day0
Sow
Spread evenly over moist potting mix. Mist.
- Day0–3
Blackout
Cover and mist daily.
- Day3
Light
Uncover and give strong light for purple stems.
- Day8–10
Harvest
Cut above the soil when the seed leaves are open.
Tips for growing kohlrabi microgreens
- Soak only 1 to 2 hours. Small brassica seed doesn't need longer.
- Sow 15 to 20 g evenly per 10 × 20 inch tray.
- Light brings colour. The purple stems get darker under strong, close light.
- Cut at 8 to 10 days, while the seed leaves are fresh and flat.
Problems and fixes
| Problem | Likely cause | Fix |
|---|---|---|
| Fuzzy white roots | Normal root hairs | Mist; they flatten when wet |
| Gray patches at the base | Mold from wet, still air | Sow thinner, water from below, add a fan |
| Tall, pale stems | Low light or late uncovering | Uncover on time, give brighter light |
| Hulls on leaves | Dry blackout | Mist before uncovering, brush off at harvest |
Kohlrabi microgreens in a mix
Purple kohlrabi grows at the same pace as broccoli, kale and red cabbage, so it mixes well in one tray. Its purple stems add colour to a mild blend. For a mix with a little heat, add a small amount of radish. See microgreen mixes.
Kohlrabi sprouts
Kohlrabi also grows as jar sprouts in about 5 days. Soak 1 tablespoon for 1 to 2 hours, then rinse and drain twice a day.
Storing and eating kohlrabi microgreens
Use within 5 to 7 days. Kohlrabi microgreens are mild enough for any salad or sandwich, and the purple stems look great in a microgreen mix with red cabbage.
Safety
For sprouts, the FDA says higher-risk groups should not eat them raw, and Health Canada advises everyone to cook sprouts.23
Purple kohlrabi FAQ
What do kohlrabi microgreens taste like?
Mild and sweet, like young cabbage. They're one of the gentlest brassica microgreens.
How long do kohlrabi microgreens take?
About 8 to 10 days after a 1 to 2 hour soak.
Why aren't my kohlrabi stems purple?
Usually low light. Purple colour develops under strong light after the blackout.
Written by Michael
A passionate sprouting professional sharing practical tips for growing sprouts and microgreens at home. More about Michael
