Question: Are radishes a winter or summer crop, and are they easy to grow?
Answer: The garden radish is a cool weather crop originating in Asia. Spring varieties (Raphanus sativus) are the common small red varieties. Winter radishes (Raphanus sativus longipinnatus) are larger, oblong and can grow 8-9 inches long.
Like carrots, radish plants are primarily grown for their roots. They are well suited to small gardens, flower beds and containers because they can grow in partial shade, are easy to grow and mature quickly.
Radish seeds can be planted in cool spring and fall weather, but growing should be suspended in the height of summer, when temperatures are typically too hot. Spring radishes require 20-30 days to reach harvest, whereas winter radishes require 50-60 days.
Favorite spring varieties include the French Breakfast, a late-maturing variety that does okay in moderate heat and the Cherry Belle that produces cherry red orbs ready in about 22 days. The Daikon is a white, Japanese winter radish that can grow up to 16 inches long.
Some gardeners consider winter radishes superior to spring because they hold their quality in the garden longer, store better and have a more distinctive flavor.
Radishes like soil that is rich in organic matter, but not compacted. Adding compost or an all-purpose fertilizer will give the radishes a boost. Practice three-year crop rotation which will help prevent disease. For spring planting, sow seeds four to six weeks before the average date of the last frost. Plant seeds outdoors ½ to 1 inch deep and 1 inch apart in rows 12 inches apart. Plant another round of seeds every 10 days or so for a continuous harvest.
Radishes like space in order to plump up so be sure to thin radishes to about 2 inches apart when the plants are a week old. Consistent, even moisture is the key for their shallow root systems. Weeds will quickly crowd out the radishes, so the successful gardener must stay attentive! For fall planting, sow seeds four to six weeks before the first fall frost.
Radishes are ready for harvest when roots reach 1 inch across. Check spring radishes often as they mature so quickly. Lift a few or push the soil aside gently to decide if they are large enough to harvest. Lift the whole plant when radishes are the right size. Do not leave radishes in the ground too long or they will become pithy.
Radishes will keep in the refrigerator for one to two weeks. You can also sprout radish seeds for salads or sandwiches. Radishes are a good source of Vitamin C, low in calories, high in fiber and are a perfect crop for the new and especially the young gardeners.