Radishes can be one of the easiest vegetables to grow and they certainly are one of the fastest, but they can also be a little fussy about their growing conditions. There are a handful of common problems that can plague home gardeners when trying to grow radishes, such as being too hot to eat, not forming a bulb or growing tough, woody, and/or cracked. There is not much you can do about these problems once you have harvested your radishes. Luckily, all of these problems are avoidable if you grow your radishes in good conditions.
01 of 04
This is one of the most common radish growing problems. Although some varieties of radishes are naturally spicer than others, the red globe type radishes we grow 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. They need to grow fast and be harvested as soon as they reach their mature size. Unlike carrots and beets, they do not get sweeter if stored in the ground.
If the problem is that you have more radishes than you can eat at one time, try succession planting your radishes, instead of planting a large area at once.
02 of 04
Why Do My Radishes Crack Open?
Sometimes radishes simply split open as they mature and get older. However very often cracking is 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 getting at least 1 inch of water per week consistently.
Just because the radish bulbs have split does not mean they are no longer 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.
03 of 04
Why Do My Radishes Get 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, like "Black Spanish", 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 hot.
04 of 04
Why Aren't the Radish Bulbs Forming? All I Have are Green Tops.
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.
Planting too thickly and not thinning to about 1-2 inch between plants will also cause radishes not to develop. If they 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 again, they will go to seed.
Another cause of underdevelopment in radishes is not enough sunlight. 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". These send down a long root that needs less space to fill out than the round globe radishes. They can take a few days longer to mature than globe radishes, but you don't need as many.
Of course, if you want to avoid this problem altogether, you can simply grow edible podded radishes - radishes grown for their crunchy, tangy seed pods, like Rat Tail. They love hot weather, have few pest problems and never form bulbs.