How to Grow Radish Microgreens

Radish is the perfect first microgreen. It germinates in 2 to 3 days, grows vigorously, rarely suffers from mould and is ready to harvest in less than a week in warm conditions. The finished shoots have a punchy, peppery flavour that is more intense than a mature radish but without any woodiness — crisp, fresh and genuinely addictive on salads, eggs, tacos and avocado toast. If you have never grown microgreens before, start with radish.

Varieties Worth Growing

Several radish varieties are sold specifically for microgreens. Daikon (also called Mooli or Chinese radish) produces milder, slightly larger shoots — a good choice if you want less heat. China Rose and Rambo are popular varieties that produce vivid pink or red stems and a sharper, more pronounced pepper kick. Hong Vit gives orange stems and a medium heat level. For the most colour and flavour, grow a mix of varieties in the same tray or experiment with one at a time to find your preference.

Sowing and Germination

No pre-soaking is needed for radish seeds. Fill a shallow tray with 2 cm of moist seed-starting mix or coco coir. Scatter seeds evenly across the surface — aim for approximately 1 to 1.5 seeds per square centimetre. This works out to about 30 to 40 grams of seed for a standard 10×20-inch tray. Press the seeds gently with a flat board to ensure contact with the medium. Mist the surface lightly with water.

Cover with a second inverted tray and keep at room temperature (18 to 22°C). Radish seeds germinate fast — most will have sprouted within 2 days. By day 3, the shoots will be reaching the cover. Lift the cover daily to check moisture levels and mist if needed.

Moving to Light and Watering

Remove the cover when most shoots are 2 to 4 cm tall and the majority have straightened upright. Move the tray to a bright south-facing window or under a grow light set 5 cm above the canopy. Radish microgreens are fast-growing and will quickly reach the cotyledon stage. Water from the bottom: fill a solid tray with 1 to 2 cm of water, set the growing tray in it for 15 minutes, then remove. This keeps the canopy dry and reduces mould risk significantly.

When and How to Harvest

Radish microgreens are ready to harvest 6 to 8 days after sowing, once the cotyledons are fully open and the stems have coloured up (pink, red or purple depending on variety). Do not wait for the first true leaves — flavour peaks at the cotyledon stage and the shoots begin to hollow slightly as energy is diverted toward true leaf production. Cut with clean scissors just above the medium. A standard tray yields 100 to 200 grams of shoots.

Rinse under cool water before eating to remove any remnant seed coats, and dry gently with a clean cloth or salad spinner. Eat fresh for best flavour — radish microgreens are at their peak the day of harvest.

Common Issues

Uneven germination is usually caused by uneven sowing — press the seeds firmly into the medium before covering. Leggy, pale shoots usually indicate insufficient light after the blackout phase; move the tray to a brighter spot or lower the grow light. Mould at the base is almost always caused by top-watering (keeping the canopy wet) — switch to bottom-watering and improve air circulation. The rapid growth cycle means radish microgreens outgrow most problems quickly, so even an imperfect tray often produces an edible crop.