Quick answer
Sow radish seeds densely on moist soil or a hemp mat, cover and weigh them down for 2–3 days of blackout, then uncover them under a grow light. Keep the medium moist by bottom watering, and harvest with clean scissors at about 8–12 days, once the first leaves have fully opened.
Radish is the crop we recommend to every beginner. It germinates in a day or two, grows quickly, tolerates small mistakes and has a peppery crunch that makes the first harvest feel worth it.
What you need
- Radish seeds sold for microgreens or sprouting (untreated)
- A tray with drainage holes and a solid tray underneath (see our tray guide)
- Potting mix, coco coir or a hemp mat
- A spray bottle and a grow light (our light picks)
Step-by-step
- Prepare the tray. Fill the holed tray with about an inch of moistened, level growing medium, or lay down a pre-soaked hemp mat.
- Sow densely and evenly. Scatter seeds so they almost touch but do not pile up. About an ounce (28 g) of seed is a common starting point for a 10×20 tray; scale down for smaller trays.
- Mist well. Spray until the seeds glisten.
- Blackout for 2–3 days. Cover with another tray and add light weight on top. Pressure helps roots anchor and gives an even stand.
- Uncover and add light. Once the seedlings push up and look yellowish, uncover them under your light for 12–16 hours a day. They green up within a day.
- Bottom-water. Add water to the solid tray when the medium feels light. Keep it moist, never soggy.
- Harvest at 8–12 days. Cut just above the medium with clean scissors when the first leaves are open and the stems are bright pink or white.
Is that fuzz mold?
On day 2–4 you may see fine white fuzz on the roots. These are usually root hairs, which collapse when misted. Cobweb-like fuzz on the surface and stems with a musty smell is mold. Here’s how to tell the difference.
Storing your harvest
Harvest when the greens are dry (water the day before, not the day of). Store them in a container lined with paper towel in the fridge, and eat them within about a week for the best flavor and crunch.
FAQ
How long do radish microgreens take to grow?
About 8 to 12 days from sowing at room temperature, including 2–3 days of blackout.
Do radish microgreens regrow after cutting?
No. Like most microgreens, radish is a single harvest. Compost the roots and medium and sow a fresh tray.
Do I need to soak radish seeds?
No. Radish seeds germinate quickly without soaking.
