How to Grow Radishes
Radishes were already being grown in Egypt over 2000 years ago and many forms are still widely cultivated. This is, again, a hardy biennial which we cultivate as an annual for the white-fleshed, edible roots. Those with red or red-and-white roots are most popular but white-skinned summerand pink or black-skinned winter types are also available. The most popular use for radishes is in spring and summer salads when small-rooted cultivars are grown rapidly—to give a crisp, fresh texture with a peppery flavour —and eaten raw.
Salad radishes can be produced virtually throughout the year—from outdoor sowings during the spring and early summer and from protected crops during the autumn, winter and early spring. When grown outside they grow rapidly enough to be a useful catch crop using land which has been recently vacated—or not yet used— or fitting well between rows of other crops such asor beans. Winter radishes, which are not commonly grown in Britain, have large solid roots which can be lifted and stored without becoming hollow.
Soil and fertilizer requirements
Rapid growth is essential to produce crisp tender roots. Those which are grown slowly are likely to be woody, and hot. Consequently you should grow radishes on rich soils which have sufficientto retain the necessary moisture, but do not dig in fresh manure immediately prior to this crop. Always sow into a deep, fine seedbed.
Seed sowing and crop management
Make the first sowings under frames or cloches in early January using short-topped, forcing cultivars. Begin outdoor sowings as soon as the ground is workable in February or March using warm, protected sites if possible. Seed can be broadcast evenly at the rate of 8g per m2 (1/3oz per sq yd) and lightly raked into the top 1cm (½ in). Alternatively sow the seed in 1-cm (½-in) deep drills spaced 15cm (6in) apart with approximately 3cm (1in) between individual seeds. Water the seedbeds generously after sowing and continue to give further waterings as necessary during growth. Protected crops must be given plenty of air on bright days so that excessive leaf growth is avoided. It will take up to 8 weeks for January sowings to mature but summer crops will be ready for pulling 3 to 4 weeks after sowing. Large rooted winter radish should be sown thinly in drills 20cm (8in) apart during July and August. Once they are big enough thin the plants to 20cm (8in) apart in the rows. This crop must be grown very rapidly to produce firm, crisp roots.
Salad radishes must be pulled as soon as they are mature. Young roots have the best flavour. Winter radishes can be lifted in the autumn and stored in boxes—as for—or left in the ground, strawed over if necessary, and lifted as needed.
Pests and diseases
Radishes are cruciferous plants and suffer from similarto brassica crops. Flea beetle and club root may be troublesome, while damping-off damage is particularly likely in thickly sown crops. Scab disease is due to another fungus which causes sunken areas on the roots.
Early, forcing types ‘Red Forcing’: the earliest round radish. ‘Saxerre’: globular roots with little top. Wood’s Early Frame. Long radish, bright rose. Maincrop types ‘French Breakfast’: red and white. ‘Cherry Belle’: rapid growing; bright scarlet roots. ‘Scarlet Globe’: globular roots; scarlet colour. ‘Icicle’: 7-cm (3-in) long white roots produced very quickly.
Winter radishes ‘Black Spanish’: black skin; white flesh; round or long available. ‘China Rose’: rose-pink; white flesh; oval shape.