When to Plant Radishes

Radishes grow best in the cooler time of the year. Most are hardy to spring and autumn chills; a few varieties can withstand the summer heat. Sow seeds for small early varieties 4 to 6 weeks before the last frost. Plant midseason or summer varieties in mid to late spring. Late varieties—called winter radishes—should be sown in the garden 10 weeks before the first expected frost.

Sow successions of early spring varieties 10 days apart until mid to late spring. Sow successions of midseason varieties every 10 days until midsummer. Resume planting for fall harvest in late August or early September.

For best quality and flavor, radishes must make rapid, even growth. Grow radishes in sandy loam or humus-rich, loosely worked soil, and supply ample moisture. If radishes go dry for even a day in warm weather, they will become tough and strong-flavored. Radishes that grow slowly have a pungent flavor and are undesirable.

Radishes remain in prime condition for only a few days, so small plantings at 7 to 10 days intervals are best.

Mild, small, quick-maturing varieties include Scarlet Globe, French Breakfast, and Cherry Belle; these will reach an edible size in 20 to 40 days.

Radish sprouts

Radish seed sowing dates

(These dates are for the Northern Hemisphere)

Average date of the last frostPlanting dates
Jan. 20Jan. 1-Apr. 1
Feb. 8Jan. 1-Apr. 1
Feb. 18Jan. 1-Apr. 1
Feb. 28Jan. 1-Apr. 1
Mar. 10Jan. 1-Apr. 15
Mar. 20Jan. 20-May 1
Mar. 30Feb. 15-May 1
Apr. 10Mar. 1-May 1
Apr. 20Mar. 10-May 10
Apr. 30Mar. 20-May 10
May 10Apr.1-June 1
May 20Apr. 15-June 15
May 30May 1-20
June 10May 15-June 1
Radishes are ready for harvest in about 20 days
Radishes are ready for harvest in about 20 days

Radish planting details

  • Sowing depth: Sow seed ½ inch (1.2 cm)
  • Space between plants after thinning: 1-3 inches (2.5-7.6cm)
  • Days to sprout: 5
  • Days to harvest: 21-25
  • Storage period: 1-2 weeks
  • Seeds per 100 row feet: 1 ounce (28 grams)
  • Yield per 100 row feet: 100 pounds (45 kg)
  • Suggested varieties: Cherry Belle, Scarlet Globe, Red Boy, Champion

Related articles of interest:

How to Grow Radishes

Radish Seed Starting Tips

Written by Stephen Albert

Stephen Albert is a horticulturist, master gardener, and certified nurseryman who has taught at the University of California for more than 25 years. He holds graduate degrees from the University of California and the University of Iowa. His books include Vegetable Garden Grower’s Guide, Vegetable Garden Almanac & Planner, Tomato Grower’s Answer Book, and Kitchen Garden Grower’s Guide. His Vegetable Garden Grower’s Masterclass is available online. has more than 10 million visitors each year.

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