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How to Grow Radishes: Quick and Easy Guide for Harvesting Peppery Roots

a bunch of red radishes with greens in a bunch
Image Credit:
Annette McCarthy
Sponsored Article:
Cummins
Botanical Name
Raphanus sativus
Grown as
Biennial
Toxicity
Non-toxic
Sun Exposure
Full Sun
Water Needs
Moderate
Height
Under 1 foot
Spread
Under 1 foot
Soil pH
Neutral
Special Features
Container-Friendly
Low Maintenance
Deer-resistant
Resilience
Cold Hardy
Plant Type
Vegetables
Written By: Catherine Boeckmann Executive Digital Editor and Master Gardener

Who knew something so small could be so mighty? Radishes are the garden’s speedsters—ready to harvest in just weeks! Whether you’re sneaking them between rows of your bigger veggies, growing them in pots, or even sowing for a winter crop, radishes are the versatile root vegetable you’ve been waiting for. With their crisp, peppery bite, they’ll add a refreshing crunch to salads and main dishes. Learn how easy it is to grow radishes.

Speedy radishes can be grown almost anywhere: between larger vegetables, around soon-to-finish crops, or in pots—and will grow peppery roots both early and late in the season. Try some for yourself, including delicious winter radishes to sow from late summer. In this short video, we’ll tell you all you need to grow them successfully.

What’s the most opportunistic crop you could possibly grow? For me, it’s the humble, lowly radish—or rather, the rousing, ravishing radish! Squeeze a sneaky row or two between larger vegetables. Sow radishes around crops that are about to finish. Grow them in pots, or squeeze in an extravagantly early or late harvest of these peppery roots. They’re super fast, super flexible—oh, and super yummy! So let’s crack on and sow some!

About Radishes

Radishes are an annual root vegetable and a member of the Brassicaceae or cabbage family, which also includes broccoli, cabbage, cauliflower, collards, horseradish, and kale. The entire radish plant is edible—from root to leaves—and can be enjoyed raw or cooked. (See cooking notes below.)

Seeds can be planted in both the spring and the fall, but sowing should be suspended when warm temperatures arrive (70°F or higher); heat causes radishes to bolt, making them essentially useless. Otherwise, radishes are one of the easiest vegetables to grow. 

Buy Seeds Now

Because radishes mature so quickly, you can sow them anywhere there is an empty space or sow in between rows of other vegetables such as beets or carrots. Radishes also happen to make excellent companion plants to help deter pests from other vegetables.

a bunch of radishes

Planting

Because of their size and speed, radishes may be grown just about anywhere. They are ready to enjoy in as little as 4 weeks and take up minimal space, but perhaps their best use is as a fill-in crop, either between or within rows of slow-to-germinate vegetables such as parsnip, or as a quick, in-and-out crop right at the start or end of the growing season.

Radishes prefer full sun but grow well in partial shade too. In hot climates, they will prefer full shade in the height of summer. Choose a sunny spot that gets at least 6 hours of sun a day. If radishes are planted in too much shade, or where neighboring vegetable plants shade them, they will put all their energy into producing larger leaves. 

Keep the soil moist, and you’ll be rewarded with clusters of mildly peppery roots in next to no time.

Till the soil (roots do not grow well in compacted soil) and remove any rocks. If the soil is clay, mix in some organic matter to loosen and improve drainage. If you’re planting longer varieties (such as ‘White Icicle’), till to a depth of 8 inches.

When to Plant Radishes

  • For a spring planting, sow seeds 4 to 6 weeks before the last spring frost.
  • For a fall crop, sow seeds 4 to 6 weeks before the first fall frost.

 See local frost dates here.

Sowing Radishes Early in Plug Trays

Begin sowing under cover from late winter, either directly into containers of potting soil, into greenhouse borders, or into plug trays of general-purpose potting mix.

Fill plug trays with potting mix, firm down, then sow a pinch of three to five seeds per module. Cover with a little more of the potting mix, then water. If it’s especially cold, you’ll need to germinate them indoors and then move them back into a greenhouse or cold frame as soon as the seedlings appear. After a couple of weeks of sheltered growth, and once the seedlings have filled out their modules, they’ll be ready to plant out under row covers or hoop houses.

Plant into soil earlier enriched with well-rotted compost or manure and raked to a fine tilth. Remove the clusters of seedlings from their modules, then dibble a hole for each plug. Drop in the plug and firm it into position so each cluster is about 6 inches or 15 centimeters apart in both directions. Cover the seedlings with row cover or horticultural fleece, properly held down at the edges, until the weather warms up.

How to Plant Radishes

Of course, sowing radishes directly where they are to grow is the easiest way to start them off. As cool-season crops, some radishes can germinate at temperatures as low as 41°F or 5°C. Sow from very early spring, initially under row covers or hoop houses, spacing rows about 8 inches or 20 centimeters apart. Sow thinly along the row—ideally, so seeds end up spaced around half an inch or one centimeter apart. Water if it’s dry and then, about a week after germination, thin the seedlings to leave them 1 inch or 2 centimeters apart within the row.

  • Add organic matter before sowing, but also avoid fresh manure or fertilizers high in nitrogen; overly rich soil will encourage lush foliage at the expense of radish roots.
  • Radish seeds have a fairly long shelf life. Don’t be afraid to plant radish seeds that are up to 5 years old. They may not all germinate, but you’ll have plenty that will.
  • Direct-sow seeds outdoors about 1/2 inch deep and cover loosely with soil. Space 1 inch apart in rows 12 inches apart. Water seeds thoroughly, down to 6 inches deep.
  • Sow another round of seeds every 10 days or so while the weather is still cool for a continuous harvest of radishes in the late spring and early summer.

Grow Some Radishes for Winter

Many hardy radishes can be sown toward the end of summer to give an autumn or early winter harvest of roots. Sowing regular red, round, or white-tipped radishes into containers is a great way to extend the season—by simply bringing pots under cover when the weather turns cold.

Another option is to grow bigger winter or Asian varieties of radish, which naturally prefer cooler temperatures. The most popular is the daikon or Japanese mooli radish. Look out for Chinese and Korean varieties too—with a mild flavor that is ideal for salads but also great in soups and stews. Then there’s the stunning watermelon radish or the chunky, spicy Spanish black radish, whose peppery tang holds up well in stir-fries.

Winter radishes are leafier than their summer cousins. The spicy leaves may be used like spinach, wilted into hot dishes, or even whizzed up in a pesto.

Sow winter radishes a little farther apart, so rows are at least 1 foot or 30 centimeters distant, then thin the seedlings to leave at least a couple of inches or 5 centimeters between each plant.

Check out this video to learn how to plant radishes:

Growing

Thinning Radishes

Thinning is probably the most important step in growing radishes. Once the seedlings are 2 inches tall or about a week old, it’s important to thin radishes to 2- to 3-inch spacings. Crowded radishes do not grow well, and you’ll end up getting small, shriveled, inedible roots.

To thin, just snip the greens at the soil line. The thinnings are edible, so add them to a salad! Or, if thinnings have been carefully extracted with roots, leaves, and stem intact, replant them. Transplants might be a bit stressed, but they should recover.

A red radish with green leaves growing in soil
Photo credit: Larisa Lofitskaya/Shutterstock

Watering Radishes

  • Consistent, even moisture is key. Don’t let the plants dry out, or you’ll get pithy, pungent roots, but don’t let them get waterlogged, or the roots will rot. A drip irrigation system is a great way to achieve a good balance.
  • Mulch the radishes with compost enriched with wood ashes to help retain moisture in dry conditions and keep root maggots at bay.
  • Weed often; weeds will quickly crowd out radishes.

Harvesting

The biggest mistake gardeners make with spring radishes is leaving them in the ground past their maturity; then, they will get tough and taste starchy. Winter radishes, on the other hand, can be kept in the ground for a few weeks after they mature, if the weather is cool. Finish the harvest before frost. 

  • To harvest, check your seed packet. Different types of radishes have different growth times. Some varieties are pulled as soon as 3 weeks after planting, when roots are approximately 1 inch in diameter. Pull one out as a test.
  • Harvest roots as soon as they have reached their final size. Don’t delay, as they can go from crisp and crunchy to woody and excessively spicy within a matter of days. Lift the biggest roots each time you harvest, so the remainder can continue to swell.
  • Another good sign that your radish root is doing well is that the green growth above the soil is 6 to 8 inches tall.
  • Finally, you should see or feel the “shoulder” or top part of the radish pushing up against the topsoil.

If some radishes bolt before you have a chance to harvest them, leave a few to develop seedpods. The seedpods, which look like tiny bean or pea pods, are quite tasty in a salad.

How to Store Radishes

  • Cut off the tops and the thin root tails, wash the radishes, and dry them thoroughly. Store in produce or zip-top bags in the crisper drawer of the refrigerator.
  • Radish greens can be stored separately for up to 3 days. Put them in a produce bag with a dry paper towel.

a pile of radishes, fresh from the garden

Pests and Problems

Radish Pests and Diseases
Pest/DiseaseTypeSymptomsControl/Prevention
Cabbage root maggotsInsectsWilted/stunted plants; off-color leaves; larvae feeding on rootsUse collars around seedling stems; monitor adults with yellow sticky traps; use row covers; destroy crop residue; till soil in fall; rotate crops
Cabbage wormsInsectsLeaves have large, ragged holes or are skeletonized; heads bored; dark green excrement; yellowish eggs laid singly on leaf undersidesHandpick; use row covers; add native plants to invite beneficial insects; grow companion plants (especially thyme); spray Bacillus thuringiensis (a bacterium that affects larvae and grubs)
ClubrootFungusWilted/stunted plants; yellow leaves; roots appear swollen/distortedDestroy infected plants; solarize soil; maintain soil pH of around 7.2; disinfect tools; rotate crops
Flea beetlesInsectNumerous tiny holes in leavesUse row covers; mulch heavily; add native plants to invite beneficial insects
White rustFungusChalk-white blisters mainly on leaf undersides; small, yellow-green spots or blisters, sometimes in circular arrangement, on upper leaf surfaces; possible distortion or galls; stems may also be infectedDestroy infected plants; choose resistant varieties; weed; destroy crop residue; rotate crops

Types

There are both “spring” and “winter” radishes. Note: The small, round varieties do not tolerate heat as well as the longer types, so plant the small types first in early spring. In general, we find that smaller radishes are milder in flavor and the larger varieties are spicier. 

  • ‘Burpee White’: spring variety; small type; heirloom radish with white crisp flesh; mild flavor
  • ‘Champion’: spring variety; small type; bright scarlet with firm, crisp white flesh; mild flavor
  • ‘Cherry Belle’: small type; round, red with white flesh; heirloom radish; crisp, light flavor
  • ‘Daikon’: winter radish; grows to 14 inches long; best grown in cooler climates or during the cooler ends of the growing season; crisp and snappy taste
  • ‘French Breakfast’: spring, late-maturing type can tolerate moderate heat; heirloom radish with 3-inch red roots, oblong shape, mild flavor
  • ‘German Giant’: spring variety, red baseball-size; never gets too hot; sweet and mild
  • ‘Spanish Black’: winter radish; large 3- to 4-inch turnip-shaped globes have crisp, pungent, spicy, pure-white flesh; great for storage
  • ‘Watermelon’: winter radish; an heirloom Daikon radish variety with striking white skin and bright red insides; mild flavor with a light peppery tang.
  • ‘White Icicle’: late spring, cylindrical white roots up to 5 inches long; can tolerate moderate heat; heirloom; mild-flavored with hints of peppery taste

Wit and Wisdom

  • For hoarseness, swallow slowly the juice of radishes. –18th-century remedy.
  • Got a mosquito bite? Apply radish juice to take away the sting and itching.

Vegetables

About The Author

Catherine Boeckmann

Catherine Boeckmann

Executive Digital Editor and Master Gardener

Catherine Boeckmann is the Executive Digital Editor of Almanac.com, the digital home of The Old Farmer’s Almanac. She leads digital editorial strategy and publishing across a wide range of Almanac sub...

Read more from Catherine Boeckmann

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Comments

<span>Dayle</span> Thu, 05/21/2020 - 16:38
The article mentions cutting, washing and storing in the refrigerator but you don't mention how long they will last. You do mention the greens, but not the actual radishes.
<span>Kat</span> Wed, 05/06/2020 - 14:14
In response to Carla, watermelon radishes are a winter radish and should be planted near Or after the summer solstice. Winter radishes are sensitive to day length and if planted when days are still getting longer they may bolt and flower without producing a large edible root.
<span>Carla</span> Wed, 04/08/2020 - 09:16
I have raised beds, I rotate my crops. My regular radishes do great, the Watermelon radish only produce leaves. What is wrong with the watermelon radish that I get no vegetable at the end?
<span>Joseph Hadi</span> Thu, 01/16/2020 - 18:41
When i plant my radishes every year plant the seeds like 1" - 2" deep after 2 weeks start sprouting but it comes out to the surface why is it happening like that . Thank you
<span>Joseph Liddle</span> Fri, 10/18/2019 - 23:18
Thickly broadcast seed, hundreds+. 1) After four true leaves, thin to 2inch, eat the thinnings. About 1-2 weeks. 2) Eat the roots, of course, about 3-4 weeks. 3) Let some go to flower. Attracts bees. 1-3 months. 4) Eat the thick green seed pods. About 3-5 months. 4) Harvest seeds when pods are dry. Save some. Sprout others to eat. About 5 months.
<span>Birdie</span> Thu, 07/04/2019 - 09:43
I as wondering if while growing the radish will the radish grow bigger if you cut the greens off while they are still growing in the ground?
<span>The Tuxedo Gardener</span> Wed, 05/29/2019 - 12:50
I have been growing radishes for years using a method of gluing, using a mixture of water and flour, the seeds at the manufactures spacing to the cheapest toilet paper. I then lay the sheet on top of the growing medium and cover with coffee grounds and lightly water for a couple days. Thus, no thinning needed. Generation rate of over 95%. The most interesting thing is the radish itself grows on the surface with the root growing into the growing medium. You see the size of the radish without pulling any out of the ground. This really improves on the success rate of the radish harvest and minimizes the amount of effort and waste.
<span>Laura Smith</span> Sun, 08/25/2019 - 15:04
do radishes come in different varities
<span>Ian Brooks</span> Wed, 05/29/2019 - 06:17
If the radishes are thinned to one or two inches apart, why does there need to be 12 inches between rows? I think this is because this advice has always been given on seed packets, probably to allow room to walk between the rows for weeding. I have had problems with all leaves and no bulb and have found a round radish F1 "Vienna", the best to grow. I get the seeds from a German-owned supermarket chain here in the UK.
<a title="View user profile." href="/author/editors">The Editors</a> Fri, 05/31/2019 - 12:09

You got it: the spacing is meant for traditional rows that you'd need to walk between. If you're growing in a raised bed or container, however, feel free to plant rows closer together.