Radishes like cool weather, but it needs to be warm and wet enough for them to fill out before the weather really heats up. The vegetable grows quickly, and it needs be harvested as soon as the radish reaches its mature size. Unlike carrots and beets, radishes do not get sweeter if stored in the ground. If you leave it too long, the radish will simply get spicier. If you have more radishes than you can eat at one time, try succession planting your radishes instead of planting a large area at once. Split or cracked radishes often are still edible. If it is just a cosmetic split or two, you can still enjoy them in your salads—no one will notice the cracks once they are sliced. Spring and fall are the easiest times to grow radishes. Some radishes, such as the ‘black Spanish’ variety, prefer being grown in the shortening days of fall. They are left in the ground over winter and harvested in the spring. Although black radishes look tough, their skin is actually quite tender. Watch out for the white flesh, though—it is truly spicy. The lack of development is caused by planting too thickly and not thinning about 1 to 2 inches between plants. If the plants are so crowded in the bed that they are rubbing against each other, they will sense there isn’t enough room to plump up, so they will go to seed. An absence of sunlight is another cause of underdevelopment in radishes. Radishes can handle a little shade, especially if the temperatures are creeping up, but they need several hours of direct sun to fully develop. You might have better luck growing one of the long, slender radishes, like ‘white icicle.’ This variety sends down a long root that needs less space than the round globe radishes. They can take a few days longer to mature, but you don’t need as many. Of course, if you want to avoid this problem altogether, you can simply grow edible podded radishes, which are radishes grown for their crunchy, tangy seed pods, like ‘rat tail.’ The plants love hot weather, have few pest problems, and never form bulbs.
