RADISH  , Raphanus sativus (nat.

order Cruciferae), in botany, a fleshy-rooted annual, unknown in the wild state . Some varieties of the wild radish, R . Raphanistrum, however, met with on the Mediterranean coasts, come so near to it as to suggest that it may possibly be a cultivated race of the same species . It is very popular as a raw salad . There are-RADIUM 807 two principal forms, the spindle-rooted and the turnip-rooted . The radish succeeds in any well-worked not too heavy garden soil, but requires a warm, sheltered situation . The seed is generally sown broadcast, in beds 4 to 5 ft. wide, with alleys between, the beds requiring to be netted over to protect them from birds . The earliest crop may be sown about the middle of December, the seed-beds being at once covered with litter, which should not be removed till the plants come up, and then only in the daytime, and when there is no frost . If the crop succeeds, which depends on the state of the weather, it will be in use about the beginning of March . Another sowing may be made in January, a third early in February, if the season is a favourable one, and still another towards the end of February, from which time till October a small sowing should be made every fortnight or three weeks in spring, and rather more frequently during summer . About the end of October, and again in November, a late sowing may be made on a south border or bank, the plants being protected in severe weather with litter or mats . The winter radishes, which grow to a large size, should be sown in the beginning of July and in August, in drills from 6 to 9 in. apart, the plants being thinned out to 5 or 6 in. in the row .

The roots become

fit for use during the autumn . For winter use they should be taken up before severe frost sets in, and stored in dry sand . Radishes, like other fleshy roots, are attacked by insects, the most dangerous being the larvae of several species of fly, especially the radish fly (Anthomyia radicum) . The most effectual means of destroying these is by watering the plants with a dilute solution of carbolic acid, or much diluted gas-water; or gas-lime may be sprinkled along the rows . Forcing.—To obtain early radishes a sowing in the British Isles should be made about the beginning of November, and continued fortnightly till the middle or end of February; the crop will generally be fit for use about six weeks after sowing . The seed should be sown in light rich soil, 8 or 9 in. thick, on a moderate hotbed, or in a pit with a temperature of from 55° to 65° . Gentle waterings must be given, and air admitted at every favourable opportunity; but the sashes must be protected at night and in frosty weather with straw mats or other materials . Some of these crops are often grown with forced potatoes . The best forcing sorts are Wood's early frame, and the early rose globe, early dwarf-top scarlet turnip, and early dwarf-top white turnip . Those best suited for general cultivation are the following: Spindle-rooted.—Long scarlet, including the sub-varieties scarlet short-top, early frame scarlet, and Wood's early frame; long scarlet short-top, best for general crop . Turnip-rooted.—Early rose globe-shaped, the earliest of all; early dwarf-top scarlet turnip, and early dwarf-top white turnip; earliest Erfurt scarlet, and early white short-leaved, both very early sorts; French breakfast, olive-shaped; red turnip and white turnip, for summer crops.- Winter sorts.—Black Spanish, white Chinese, Californian mammoth .