Learning Download: How to Grow Radishes
Radishes are the perfect vegetable for new gardeners. They can be eaten raw or added to salads for an extra crunch with a bit of flavor. Although oftentimes the tops are composted, radish greens also can be eaten by sautéing them in a pan or adding raw greens with the radishes to a salad.
Before Planting: Only grow radishes in the spring and fall because if grown in warmer months they will bolt, creating a bitter flavor with a woody texture in the roots.
Planting: Radishes require well drained soils with a pH range of 6-7.0. Direct sow at any time during the season, beginning in early spring into early fall. Plant about 10 seeds/ft, 1/2″ deep, rows 1′ apart. Radishes are adversely affected by hot, dry weather. They remain in prime condition only a few days and should be grown rapidly with plenty of moisture to be mild, tender, and attractive.
Watering: Water every other day so that the soils is moist, but not over watered.
Fertilizer: Since radishes grow so fast, they don’t need fertilized during their growth but can benefit from soil that is fertilized prior to planting the seeds. Before planting, spread a 2-inch layer of compost over the furrows where the radish seeds will grow. Sprinkle ½ pound of 16-20-0 fertilizer per 50 square feet of radishes. Mix the compost fertilizer blend into the top 6 inches of soil. Avoid fertilizers high in nitrogen. Instead of fertilizing after planting the radishes, spread mulch enriched with wood ash around the plants.
Days to Maturity: Radish roots can be ready to harvest in as little as 21 days.
Harvesting: Harvest promptly to avoid pithiness, beginning at about 3-4 weeks when roots are the size of a large marble. Radishes are ready to harvest when the leaves are 4 inches tall. Red radishes are ready to harvest when the roots are approximately 1 inch in diameter. White radishes are ready to harvest when the roots are ¾ inch in diameter.Wash with cool water and refrigerate. Radishes will keep 3-4 weeks in good, crisp condition if kept at 32°F and 95% relative humidity.
Tips: When planted near cucumbers, peppers and squash, radishes can draw aphids away from the other plants.
AVG. Seeding Rate: 1 oz./70′, 14 oz./1,000′, 21 lb./acre at 35 seeds/ft. in rows 18″ apart, or 31 lb./acre in rows 12″ apart.