This article was published originally on 3/7/2012
Radishes are a cool-season, fast-maturing, easy to grow vegetable. They can be eaten fresh, added to salads, dips, sandwiches and stir-fries, or utilized as garnishes or decorations.
Suggested radish varieties for home gardens include 'Champion' (scarlet red, globe-shaped, white flesh, 20 to 25 days), 'Cherriette' (cherry red, round to globe-shaped, white flesh, 20 days), 'Cherry Belle' (bright cherry red, round to globe-shaped, white flesh, 24 days), 'Comet' (ruby red, round, white flesh, 25 days), 'Ping Pong' (pure white, round, white flesh, 30 days), 'Sparkler' (bright red top with white tip, round, white flesh, 25 days), and 'White Icicle' (snow white, slender tapered 4 to 6 inches long, white flesh, 28 to 30 days).
Radishes can be planted as soon as the ground can worked properly in spring. This is often late March in southern Iowa and mid-April in northern counties. Successive plantings can be made every 7 to 10 days through May. Radish plants flower and their roots become pungent with the onset of hot weather. Several plantings can also be made in late summer (mid-August to late September) for a fall crop.
Sow radish seeds one-half inch deep in rows that are 12 inches apart. When the seedlings emerge, thin the planting so remaining plants are 2 inches apart.
Radishes can be harvested 3 to 5 weeks after planting. Periodically check their development by pulling one or two plants as they approach maturity. Harvest radishes when roots reach useable size (about 1 inch in diameter). Radishes can be stored in the refrigerator for 2 to 3 weeks. Prior to storage, cut off the foliage to within ½ inch of the roots. Radishes get pithy and hot when harvested too late.
Overcrowded plants produce small, misshapen roots. Hot, pithy radishes may be the result of hot weather or harvesting too late. Excessive nitrogen, the rapid onset of hot weather, or overcrowding may produce plants that are all tops (lush foliage, little or no root development).