Radishes are a hardy, easy-to-grow root vegetable that can be planted multiple times in a growing season. They are grown for their root and their edible leaves. Plus, radishes can be harvested as soon as 3 weeks after planting! Here’s our full guide on how to grow radishes in your garden.
About Radishes
Radish seeds can be planted in both the spring and the fall, but growing should be suspended in the height of summer, when temperatures are typically too hot. (Hot temperatures may cause radishes to bolt, making them essentially useless.)
Otherwise, radishes are one of the easiest vegetables to grow.
Selecting and Preparing a Planting Site
- Plant in a sunny spot. If radishes are planted in too much shade—or even where neighboring vegetable plants shade them, they will put all their energy into producing larger leaves.
- Like carrots, radish plants are primarily grown for their roots. Though the soil needs to be rich in organic matter, it should not be compacted. If your soil is more clay-like, mix in some compost to loosen it and improve drainage.
- If your soil isn’t rich in organic matter, incorporate a few inches of aged compost or all-purpose fertilizer (see packaging for amount) into the planting site as soon as the soil is workable.
- Till your garden bed to remove any rocks or dirt clods before planting.
- Practice 3-year crop rotation. In other words, only plant radishes in the same spot every third year. This will help prevent diseases from affecting your crop.
When to Plant Radishes
- For a spring planting, sow seeds 4 to 6 weeks before the average date of your last spring frost. See local frost dates here.
- Fall planting is also possible with radishes. You can plant radishes later than any other root crop in late summer or early fall and still get a harvest. Sow seeds 4 to 6 weeks before the first fall frost.
How to Plant Radishes
- Radish seeds have a fairly long shelf life. Don’t be afraid to plant radish seeds that are up to five years old. All may not germinate, but you’ll have plenty that will.
- It’s best to sow radish seeds directly in the garden so as not to disturb their roots. Directly sow seeds outdoors ½ to 1 inch deep and 1 inch apart in rows 12 inches apart.
- Sow another round of seeds every 10 days or so while weather is still cool for a continuous harvest of radishes in the late spring and early summer.
Check out this video to learn how to plant radishes:
- Crowded plants do not grow well. Thin radishes to about 2 inches apart when the plants are a week old by snipping the greens at the soil line. The thinnings are edible, so add to a salad..
- Consistent, even moisture is key. Keep soil evenly moist but not waterlogged. A drip irrigation system is a great way to achieve this.
- Putting a thin layer of mulch around the radishes can help retain moisture in dry conditions.
| Pest/Disease | Type | Symptoms | Control/Prevention |
|---|---|---|---|
| Cabbage root maggots | Insects |
Wilted/stunted plants; off-color leaves; larvae feeding on roots |
Use collars around seedling stems; monitor adults with yellow sticky traps; use row covers; destroy crop residue; till soil in fall; rotate crops |
| Cabbage worms | Insects |
Leaves have large, ragged holes or are skeletonized; heads bored; dark green excrement; yellowish eggs laid singly on leaf undersides |
Handpick; use row covers; add native plants to invite beneficial insects; grow companion plants (especially thyme); spray Bacillus thuringiensis (a bacteria that affects larvae and grubs) |
| Clubroot | Fungus |
Wilted/stunted plants; yellow leaves; roots appear swollen/distorted |
Destroy infected plants; solarize soil; maintain soil pH of around 7.2; disinfect tools; rotate crops |
| Flea beetles | Insect |
Numerous tiny holes in leaves |
Use row covers; mulch heavily; add native plants to invite beneficial insects |
| White rust | Fungus |
Chalk-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 infected |
Destroy infected plants; choose resistant varieties; weed; destroy crop residue; rotate crops |
- ‘French Breakfast’: a late-maturing variety that does OK in moderate heat.
- ‘Watermelon’: a mild, sweet radish with white skin and a pinkish center.
- ‘Burpee White’: spring variety, white skin.
- ‘Daikon’: A white, Japanese, “winter radish” that gets large (up to 16 inches long). Best grown in cooler climates or during the cooler ends of the growing season.
- ‘Rat’s Tail’: These radishes are grown for their seedpods rather than their root. The pods offer a tangy, spicy flavor stronger than your usual radish.
- ‘Dragon’s Tail’: Like ‘Rat’s Tail’, these radishes are grown for their seedpods. The pods of this variety are thinner and turn a lovely purple color.
How and When to Harvest Radishes
- Radishes will be ready to harvest quite rapidly, as soon as 3 weeks after planting for some varieties.
- For most varieties, harvest when roots are approximately 1 inch in diameter at the soil surface. Pull one out and test it before harvesting the rest!
- Do not leave radishes in the ground long after their mature stage. Their condition will deteriorate quickly.
- Cut the tops and the thin root tail off, wash the radishes, and dry them thoroughly. Store in plastic bags in the refrigerator.
- Radish greens can be stored separately for up to three days.
- For hoarseness, swallow slowly the juice of radishes. –18th-century remedy
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Got a mosquito bite? Apply radish juice to take away the sting and itching.
