Winter radish is the radish's big relative, the same species but with roots that grow 20 to 40 cm long and weigh several hundred grams. It grows through the autumn, keeps through the winter and tastes milder the cooler it grows. One single thing decides whether it works, and that is when you sow.
Sow in July, not in spring
Winter radish is a short day plant. Sow it in spring, when the days are getting longer, and the plant reads that as a signal to flower instead of storing in the root. The result is a long flower stalk and a thin, stringy root.
Sow from mid July to early August instead, when the days are shortening. Then all the plant's energy goes down into the root.
Depth: 2 cm.
Row spacing: 30 to 40 cm.
Germination: 4 to 8 days.
Harvest: 8 to 12 weeks after sowing, so October or November.
That makes winter radish one of the few crops that fits a bed where you have just lifted early potatoes or peas. More sowings of that kind are covered in the article on autumn sowing.
Thin early
Thin to 10 to 15 cm between the plants once they have two true leaves. For daikon varieties, which grow longer and thicker, thin to 15 to 20 cm.
If you leave the thinning too late the plants compete, and you get many small roots instead of a few large ones. The seedlings you pull can be eaten as leafy greens.
The soil decides the shape
The root grows straight down, and if it meets an obstacle it splits in two. Deep, loosened, stone free soil is not a detail here, it is the whole precondition.
Loosen 30 cm deep before sowing, without turning the soil over.
Pick out stones in the sowing row.
No fresh manure. It gives forked and hairy roots. Feed the bed the year before instead.
pH 6 to 7. Winter radish is a brassica and gets clubroot in acid soil.
Even watering gives mild flavour
The heat in winter radish comes from mustard oils, and the level rises when the plant is kept warm and dry. A root that has grown evenly in cool autumn soil tastes milder than the same variety grown in drought.
Water evenly all the way through. Uneven watering gives collapsed, spongy roots with cavities inside.
Types
| Type | Appearance | Flavour | Good for |
|---|---|---|---|
| White winter radish | Long white root, 20 to 30 cm | Mild, slightly peppery | Salad, pickling, stir fry |
| Daikon | Very long, 30 to 40 cm | Mildest of them all | Asian dishes, pickling |
| Black radish | Round to oblong, black skin | Sharp and strong | Grated with apple, storage |
| Münchner Bier | White and short | Strong | Sliced with salt alongside beer |
Our variety Rammenas Icon belongs to the white, mild type and gives long roots with firm, crisp flesh. More varieties are found among our radish seeds.
Harvest
Lift the roots before the ground freezes, usually in October or November. The root takes light night frost but not ground that freezes all the way through.
Loosen the soil with a garden fork along the row first. If you pull straight up by the tops on a 30 cm daikon, it snaps in the middle.
Store in sand
Twist off the tops and leave a couple of centimetres.
Brush off the soil. Do not rinse.
Layer the roots with damp sand in a box.
Keep the box cool, 0 to 4 degrees.
Stored that way they keep three to four months. Black radish stores best of the types, daikon worst.
Winter radish as a soil improver
The long taproot is used in farming to break up compacted soil. The root drills down through the pan, freezes apart over winter and leaves a channel behind that the roots of the next crop can follow.
The same works in a raised bed or on a bed that has gone hard. Sow thickly in August, leave the plants standing over winter and let the roots break down where they are.
Pests
Flea beetles are worst on newly sown plants in the August heat. Cover with fleece until the plants have four leaves.
Cabbage root fly lays eggs at the stem base and the larvae go for the root. Netting with 0.8 mm mesh stops both.
Cabbage white butterfly takes the foliage. The full rundown is in the article on the cabbage white butterfly.
If you want something faster in the same row, radish is ready to harvest in three to four weeks.
Author: Emma Vogiatzi
Fact-checked by Erik Hoekstra
Last updated 2026-08-31