Why Didn't My Radishes Develop Well?

Are the roots of the radishes enlarged and club-like?

Are the roots of your radishes riddled with slimy, winding tunnels?

Are the roots small and imperfect?

Are the leaves yellow or pale?

Are the leaves purple?

Are the roots tough and dry and the flash is pithy with white spots?

Do the roots have rough, dark spots on the skin?

Are the roots soft and shriveled?

Are the roots cracked, but the skin and flesh inside look normal?

Enlarged and club-like roots are most likely caused by the fungal disease - Club root. Remove and destroy any infected plants. ‘Red King’ and ‘Saxafire' are tolerant cultivars.

If the radish roots are riddled with slimy, winding tunnels, the plant is infested by cabbage maggots. These white, 1/4 of inch larvae feed on roots and transfer bacterial and fungal diseases. Remove and destroy infected plants. Solarizing the soil will help reduce maggot populations in problem areas.

Your plant is most likely suffering from nitrogen deficiency. Spray leaves with compost tea or fish emulsion or side-dress with compost to correct the deficiency.

Your plant is most likely suffering from phosphorus deficiency. Spray leaves with compost tea or fish emulsion or side-dress with compost to correct the deficiency.

Your radishes might be suffering from environmental issues or improper care. If the soil was dry, water subsequent plantings well. Do not try to grow most radishes in the hottest summer months, wait until cooler fall weather. Planting radishes in the shade of other plants may somewhat extend the spring season.

Excessive heat usually causes tough and dry roots. Few radishes tolerate high summer temperatures. Select heat-tolerant cultivars or plant earlier or later during the year.

The fungal disease Scab often causes problems for radishes. This disease is a problem mostly in dry soil when pH is high and magnesium is low. Keep soil moist and maintain a pH below 6.5. Spray foliage with Epsom salts (1 tablespoon per gallon of water) or side-dress with compost to add magnesium.

Soft and shriveled roots are caused by a cold injury. When temperatures drop below 32°F you should protect your radishes with the layer of mulch.

Your radishes may have overmatured or the soil moisture is uneven. Radishes are at their best for only a few days. If left unharvested, they quickly develop a harsh flavor and often crack open. You can keep soil evenly moist by using mulch.

Cracked roots with rough skin and dark flesh are symptoms of Downy mildew or black rot disease. Prevent these fungal diseases by providing well-drained soil and by using a 4-year rotation.