Overview
What radishes need, how fast they grow, and whether they suit your space.
Salad radishes go from seed to plate in about a month, which makes them a good first crop for children. Grown fast in cool, moist soil they are crisp and mild. Slow growth or summer heat makes them hot and woody.
Quick facts
- Botanical name
- Raphanus sativus
- Feeding
- Light feeder
- Temperature
- 27 °C
- Hardiness
- Any zone, as an annual
- Time to harvest
- 25 – 45 days
- Height
- Up to 45 cm (18 in)
- Propagation
- Seed
Optimal growth
Growing details
- Germination
- 5 – 10 days
- Spacing
- 3 cm (1.2 in)
- Sowing depth
- 10 mm (⅜ in)
- Frost sensitivity
- Frost hardy
Growing calendar
- Sow outdoors: February, March, April, May, June, July, August, September
- Harvest: April, May, June, July, August, September, October, November, December
In the UK: salad radishes in spring, early summer and late summer (from February under cloches); winter radishes July and August (RHS). In the UK: salad radishes four to eight weeks after sowing; winter radishes from November (RHS).
Is this plant right for you?
- Ready in a month
- Beginner friendly
- Good with children
- Small spaces
- Grows in pots
- Cool-season crop
- Sow little and often
Good to know
It does well in a pot indoors or out, so you do not need a bed for it. It stands frost, so it can go out earlier than tender crops.
Before You Grow
Choose salad, winter, daikon or seed-pod radishes, and a sunny spot with fine, stone-free soil.
Radishes are brassicas: rotate them with cabbage-family crops (RHS, Utah State).
What you need
Seed
Salad, winter, daikon or seed-pod radishes. See choose your radishes.
A fine seedbed
Forked, stone-free and raked. See soil.
A watering can with a rose
Even moisture is everything. See watering.
Fleece
Against flea beetles and root fly. See pests.
Or a container
For salad radishes. See containers.
Choose your radishes
There are four types, grown at different times (RHS).
Salad (summer) radishes are small, fast and peppery, sown from spring to late summer. Round red ‘Scarlet Globe’, long red-and-white ‘French Breakfast’, purple ‘Amethyst’ and white ‘Ping Pong’ are RHS AGM choices. ‘French Breakfast’ and ‘Icicle’ cope with heat better than most (Illinois).
Winter radishes are hardy, larger and slower, sown in July or August in the UK for winter: ‘Black Spanish Round’, ‘China Rose’. Sown too early they bolt without forming a root (RHS).
Oriental (daikon or mooli) radishes have long, mild white roots of 30 cm (1 ft) or more, for late summer and autumn: ‘April Cross’.
Seed-pod radishes such as ‘Rat-Tailed’ are grown for crunchy, spicy pods and do well in hot weather (RHS, UMD).
Radish types compared
-
Salad
- Sow (UK)
- Spring to late summer
- Spacing
- 2.5 to 5 cm (1 to 2 in)
- Ready in
- 4 to 8 weeks
- Examples
- ‘Scarlet Globe’, ‘French Breakfast’
-
Winter
- Sow (UK)
- July to August
- Spacing
- 15 to 20 cm (6 to 8 in)
- Ready in
- From November
- Examples
- ‘Black Spanish Round’, ‘China Rose’
-
Oriental (daikon)
- Sow (UK)
- Spring and summer
- Spacing
- 15 to 20 cm (6 to 8 in)
- Ready in
- 8 weeks or more
- Examples
- ‘April Cross’
-
Seed pod
- Sow (UK)
- Spring and summer
- Spacing
- 10 cm (4 in)
- Ready in
- Pods over several weeks
- Examples
- ‘Rat-Tailed’
From the RHS. For salads within weeks, a salad radish; for winter use, a winter radish or daikon.
Where radishes grow best
Radishes are a cool-season crop, at their best in mild spring and autumn weather (RHS, Illinois).
Sun. An open, sunny site, at least six hours a day (UMD). Light shade is fine for salad radishes in midsummer (RHS); deep shade gives all leaf and no root (Illinois).
Temperature. Seed germinates best at 13 to 24 °C (55 to 75 °F); plants grow best below 27 °C (80 °F) (Utah State). For what heat does to the roots, see common problems.
Frost. Plants withstand heavy frosts in spring and autumn (UMD).
Gap-filling. Fast salad radishes fill gaps between slow crops or in beds meant for later warm-season crops (RHS, Illinois).
- Germination
- 13 to 24 °C (55 to 75 °F)
- Best growth
- Below 27 °C (80 °F)
- Sun
- 6 hours; light shade in midsummer
Soil
Radishes grow in almost any well-prepared, fertile soil that stays moist (Illinois). Deep, sandy, well-drained soil rich in organic matter suits them best (Utah State).
Preparation. Weed, fork through to break up lumps and compaction, remove stones, then rake to a fine texture (RHS). No-dig growers sow into a compost mulch.
Heavy soil needs plenty of compost for roots to develop (Utah State).
Long roots. Winter radishes and daikon need deep soil: some grow more than 30 cm (1 ft) long (RHS).
Fertiliser. Radishes need little. See feeding.
Planting
Sow little and often from early spring, thinly, and thin early.
Sown 2.5 cm (1 in) apart, salad radishes need no thinning (RHS).
When to sow radishes
Sow salad radishes as soon as the soil can be worked in spring (UMD, Illinois), once it reaches about 4 °C (40 °F) (Utah State).
In the UK, spring, early summer and late summer give the best results; from February in pre-warmed soil under cloches for an early crop (RHS). Avoid sowing in hot, dry weather.
In the US, two to three weeks before the last frost; in Utah, again from mid-August to early September for autumn (Utah State).
Little and often. A short row every 10 to 14 days (Illinois) gives a steady supply instead of a glut.
Winter radishes in July or August in the UK (RHS).
- As soon as the soil can be worked.
- Short rows every 10 to 14 days.
- Skip hot, dry spells.
How to sow radishes
Sow radishes where they’ll grow (RHS, UMD).
-
Make a drill
1 cm (⅜ in) deep for salad radishes, 2 cm (¾ in) for winter types, with rows 15 cm (6 in) apart (RHS).
-
Sow thinly
Salad radishes 2.5 to 5 cm (1 to 2 in) apart; winter and daikon 15 to 20 cm (6 to 8 in); seed-pod radishes 10 cm (4 in) (RHS).
-
Cover and water
With a thin layer of soil (UMD), then keep the surface evenly moist until seedlings are up (Utah State).
-
In summer, pick a cooler spot
Light shade, out of the midday sun (RHS).
-
Or broadcast on a bed
Scatter seed lightly and thin to 5 to 7.5 cm (2 to 3 in) apart each way (Illinois).
Thinning radishes
Crowded radishes make leaves and no roots (RHS, Illinois). Thin early.
-
Check the spacing
Salad radishes need at least 2.5 cm (1 in), winter and oriental radishes 15 cm (6 in) (RHS).
-
Thin as soon as they’re up
Remove the smaller, weaker seedlings first (RHS).
-
Eat the thinnings
Young leaves go into salads as microgreens (Gardeners’ World).
Care
Watering, feeding, pots, and radishes as catch crops.
Stress in the first six weeks often leads to early flowering and poor roots (Utah State).
Care by growth stage
Seedlings
Pests: flea beetle
Thin, and weed by hand close to the roots: a hoe damages them (RHS). See thinning.
Roots swelling
Water: little and often
Water evenly. See watering.
Ready
Salad: at 2.5 cm (1 in)
Pull promptly. See harvesting.
End of season
Winter types: dig as needed
Pull any roots left before they turn woody, and clear the row. See harvesting.
Watering radishes
Keep the soil consistently moist for fast, even growth and succulent roots (RHS).
Evenly. Dry soil, or a soaking after a dry spell, spoils the roots; see common problems.
How. Water regularly in dry spells; mulch helps hold moisture (Utah State). Containers dry out fastest.
Spring sowings, when rain is plentiful, often do better than summer ones (RHS).
Feeding radishes
Radishes have a low nutrient requirement (UMD). Soil prepared with organic matter usually needs nothing more.
Before sowing. Fertilise only where a soil test shows it’s needed (Utah State).
Avoid excess nitrogen: it makes big tops and small roots (UMD).
Side-dressing. Utah State gives a light nitrogen feed three to four weeks after emergence, about ¼ cup of 21-0-0 per 3 m (10 ft) of row, to keep growth rapid.
Radishes in containers
Short-rooted salad radishes grow well in containers (RHS), and can be sown in late winter in a cold frame or window box for an early crop (Illinois).
Container. At least 30 cm (1 ft) wide and deep, filled with multi-purpose compost (RHS).
Sow as in the ground, 2.5 cm (1 in) apart.
Water often: pots dry out much faster than beds.
Radishes as row markers and catch crops
Radishes are ready before slower neighbours need the space.
Row markers
Grow together · Agronomic reason
A pinch of radish seed in a row of slow-germinating carrots, beets or lettuce comes up in days and marks the row; the radishes are pulled before the main crop needs the room (UMD, RHS).
Between slow crops
Grow together · Agronomic reason
Sow between broccoli, Brussels sprouts or peas, or where tomatoes, peppers and squash will go later (Illinois, RHS). Radishes are brassicas and share pests and diseases such as clubroot, so rotate them with the cabbage family from year to year (RHS, Utah State).
Problems
Roots that don’t form, turn hot or split, a few pests, and brassica diseases.
Common radish problems
Match what you see to its likely cause.
All leaf, no root
- Crowding
- Heat
- Shade
Sown too thickly and not thinned, too hot, or deep shade (Illinois, Utah State). Thin to spacing and sow in cool weather.
Hot, woody or pithy roots
- Too old
- Slow growth
Grown too slowly or left too long (Illinois). Pull salad radishes young; water evenly.
Split roots
- Uneven water
- Too old
Old roots, or rain after a dry spell (Illinois). Water regularly in dry spells and pull roots promptly. Split roots are usually still edible (RHS).
Bolting
- Heat
- Drought
Plants flower instead of making roots in hot, dry weather (RHS). Water in summer, sow in cooler months, or harvest the pods.
Common pests
Flea beetles
Tiny holes in the leaves, usually only cosmetic (RHS). Fleece or row covers keep them off seedlings (Gardeners’ World, Utah State).
Cabbage root fly
White maggots tunnel into roots, especially in late summer. Rarely a problem for fast-growing salad radishes; cover slower winter and oriental types with fleece (RHS, Utah State).
Slugs
Eat seedlings, especially in damp weather (RHS). Protect rows as soon as you sow (Gardeners’ World).
Common diseases
Downy mildew
Whitish fuzz under leaves and yellow patches above (RHS). Remove affected leaves, give plants space for air, and rotate.
Clubroot
Swollen, distorted roots on cabbage-family crops (RHS). Rotate with other brassicas.
Harvest & Use
Pull salad radishes young; winter radishes can wait in the ground.
Harvesting radishes
Salad radishes are ready in as little as four weeks, when about 2.5 cm (1 in) across; early sowings take six to eight weeks (RHS). Utah State gives 25 to 45 days. Pull them promptly: left too long they turn pithy and hot. A radish that gives when squeezed is likely fibrous (Illinois).
Winter radishes can stay in the ground and be dug as needed through winter, protected with cloches, fleece or cardboard in freezing weather, or lifted in November (RHS). They stay crisp even when large.
Daikon take at least eight weeks and hold well in the ground without turning woody (RHS).
Seed pods. Pick young and often: old pods turn stringy and the plant stops flowering (RHS).
Leaves are edible too, raw or cooked like chard (RHS).
- Salad radishes at 2.5 cm (1 in).
- Check every few days.
- Winter radishes can wait.
Storing and using radishes
Eat salad radishes fresh. To keep them, cut off the leaves, which draw moisture from the root (Illinois).
Fridge. Wrapped in a plastic bag: estimates vary with conditions: 5 to 7 days (Illinois), one to two weeks when cold and very humid (UMD), or two to four weeks (Utah State). Plan on a week. Winter radishes keep up to two weeks. Store the greens separately and use them within 2 to 3 days.
Winter storage. Winter radishes pulled before the ground freezes keep for several months in moist, cold storage (Illinois).
Using. Slice or grate raw into salads; cook winter radishes and daikon in stews and stir-fries like turnips (RHS).
More to Explore
Short answers, guides that pair well with radishes, and the sources behind this one.
Frequently asked questions
How long do radishes take to grow?
Salad radishes about four to six weeks; early spring sowings six to eight. See harvesting.
Why are my radishes all leaves and no root?
Usually crowding, heat or deep shade. See common problems.
Why are my radishes so hot?
They grew too slowly or are too old. See common problems.
When should I sow radishes?
Salad radishes from early spring, every 10 to 14 days, avoiding hot, dry spells; winter radishes in midsummer. See when to sow.
Do radishes need thinning?
Salad radishes only if closer than 2.5 cm (1 in); winter and oriental radishes need 15 cm (6 in). See thinning.
Can I grow radishes in pots?
Yes, salad radishes. See containers.
Can you eat radish leaves?
Yes, raw or cooked like chard. See harvesting.
Why did my radishes split?
Rain or watering after a dry spell, or roots left too long. See common problems.
Related guides
Sources
- How to grow radishes (opens in a new tab) Royal Horticultural Society
- Radish (opens in a new tab) University of Illinois Extension
- Radishes in the garden (opens in a new tab) Utah State University Extension
- Growing radishes in a home garden (opens in a new tab) University of Maryland Extension
- How to grow radishes (opens in a new tab) BBC Gardeners’ World