Black Spanish Round Radish Guide
Radishes grow best in cooler weather between 40°F-70°F. They do great in containers and small gardens. Bank on Seeds recommends direct seeding.
If Direct Seeding
- Direct seed outside 2-3 weeks before last frost date; or
- Direct seed into a container 6-8 inches deep and wide anytime of the year. It can be placed outside when the temperature is between 45°F-70°F; or
Begin the growing season early and start the radish seeds indoors in trays or pods 4-6 weeks before the last frost date. Germination is best and fastest between 50°F-75°F. It can be transplanted outside 3 weeks later.
Sow seeds ½ inch deep and 1-2 inches apart with rows spaced 12-16 inches apart. Germination will take 6-10 days.
Radish likes well-draining soil free of debris, rocks, and weeds with lots of organic matter. They also love full sun but does best in cooler weather. Water regularly and consistently to avoid forming uneven or bumpy shaped radishes. Keep the soil moist but not wet – check the top 1-2 inches of soil and if dry, then water it.
Radishes grow too fast to require any fertilizer but if needed aged compost can be mixed into the top of the soil.
Radishes are full grown in 22-30 days. The radish can be picked when the root reaches 3/4” across. Gently move side to side to assess the size is right before pulling out for some fine garnishes or use in salads. Harvest as soon as they are ready otherwise they taste pithy.
Aphids, root maggots – handpick or spray off, neem oil
*Companion plant radishes with beets, cucumbers, lettuce, peas, parsnip, peppers, and nasturtiums. When planted near cucumbers, peppers and squash, radishes can draw aphids away from the other plants. Avoid planting with cabbage, cauliflower, broccoli, and turnips.*