Seeds of this quick-growing vegetable may be sown for salads at intervals from early March to October. It is generally treated as a catch crop, being sown on a piece of ground which is intended for cabbages or some other crop to be planted subsequently. A rich, moist soil and cool conditions yield the most succulent radishes. Slow growth may cause them to have a rather hot, unpalatable taste.
Sowings in March or early April may be made in the cold frame or under cloches. Sow the seeds in 2.5cm (1 in) deep drills, the drills being 15cm (6in) apart. Sow thinly to avoid having to thin out. Remember each radish needs at least 6 sq cm (1 sq in) of surface area. Sow similarly in open ground. Prevent annual weeds from smothering the seedlings and soak the rows with water if the soil is on the dry side. There are many varieties and ‘French Breakfast’ is probably the most popular. ‘Sutton’s Red Forcing’ is suitable for cloche and frame sowings. The long, white radish, `Icicle’, is liked for its flavor.
Winter radishes are large and may have a black skin, as in the variety `Black Spanish’, or a red skin such as ‘China Rose’, or a white skin like ‘All Season’. Do not sow winter radishes until June and space the rows 30cm (1 ft) apart. Thin the seedlings to 23cm (9in) apart, and keep the rows free of weeds. Water well in dry summer weather. Lift the roots in October and store them in slightly moist sand.