4 Common Problems with Growing Radishes

Problem: Ultra-Spicy Radishes

A too-hot radish is one of the most common problems with radishes. Although some varieties of radishes are naturally spicer than others, the red globe type radish frequently grown for salads should be quite palatable. If your globe radishes seem too hot to eat, it is probably because of the length of time they have been growing—the radishes either grew too slowly or are too old.

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.

Problem: Cracked Radishes

Sometimes radishes split open as they mature and get older. cracking Cracking is often the result of uneven watering. Trying to make up for a period of drought with a lot of water all at once will cause the radish to grow too rapidly on the inside and split open. Make sure your radishes are consistently getting at least 1 inch of water per week.

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.

Problem: Tough, Woody Radishes

Leaving radishes in the garden too long can also cause them to become tough and woody. Radishes need to grow quickly to ensure they are tender and plump when harvested. If radishes don’t get the cool temperatures they need and lots of regular water, they will take longer to reach their mature size, and you may be tempted to leave them in the soil until they fill out. That's when they start to get hard and dry.

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.

Problem: All Leaves, No Bulbs

Radishes that don't form bulbs don't do much good for the gardener who wants radish slices for their salad. The most frequent cause of radishes growing only greens is hot weather. Once the weather warms up, the radish plant bolts and tries to set seed.

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.