Radishes do not need to be watered every day but they should have at least 1 inch of water each week. The soil should be moist but not soaked.
Radish seeds should be planted in moist soil in mid-spring. Infrequent watering gives radishes a woody texture and a hot taste. Adding too much water after a dry period will cause radishes to grow too quickly and split. Radishes grow best during the cool days of spring and fall, but adequate watering will help extend the summer harvest. Radishes are best eaten fresh or pickled, as their high water content makes them difficult to freeze or to dry.