Q. What causes my radishes not to bulb?
A. Radishes will fail to bulb for several reasons. Probably, they are not properly thinned and are growing too close together. Thin plants to a spacing of one inch apart when plants first emerge. Radishes should be seeded two to three seeds per inch and thinned when they are about 1 to 2 inches tall to a spacing of one inch apart. Radishes will also not bulb properly when forced to mature during temperatures above 80 degrees to 85 degrees F.
Q. Sometimes my radishes have a hot, bitter flavor. What is the problem?
A. Off-flavored radishes are caused by planting at the wrong time or poor cultural practices such as low fertility or low moisture resulting in slow growth. For highest quality, radishes should grow fast. Fast growth can be stimulated by adequate fertility and maintaining the soil in a good moisture condition. If radishes are too old, they taste hot.
Q. What causes roots of radishes to crack?
A. This is usually caused by waiting too late to harvest the radishes. Cracking is caused by fluctuations in moisture which cause the root to swell rapidly and crack, especially near maturity.
Q. Are the leaves of radish plants edible?
A. Radish leaves are not poisonous and can be consumed although they have a strong, bitter flavor. There may be some dishes or some methods of preparing radish leaves which would make them more palatable, but for the most part they lack a desirable flavor.
Q. What are winter radishes and how do they differ from regular garden radishes?
A. Winter radish varieties produce large roots which may be round or elongated and white, red or black. They require a long season for full growth. The roots may be eaten raw with vinegar or cooked like turnips. The flavor of winter radishes is usually pungent and the texture move fibrous and less crisp than common garden radishes.
Q. My radishes have a black, crusty growth around the globe.
A. This is scab, a soilborne disease. It can be controlled by rotation within the garden to avoid planting in infected soil.
Radishes have the same insect problems as mustard.