White Radish Seeds

White Radish (Daikon, Raphanus sativus var. longipinnatus) is the long, ivory-white oriental radish prized for its crisp, juicy flesh and a mild, clean sharpness that is noticeably gentler than the small round salad radishes. Its smooth pale roots grow long and shapely, and as they mature the shoulders push up out of the soil, making harvest easy to judge. This is a winter/oriental type that takes a little longer to size up but rewards you with a tender, refreshing root that is wonderful grated raw into salads, sliced into pickles, or simmered into cooked and braised dishes.

Planting

White radish is a cool-season crop, and as a winter/oriental type it is best sown in mid- to late summer in temperate climates. In Egypt, lean on the mild winter window: in the Nile Delta and Lower Egypt sow roughly from late October to early February, and in warmer Upper Egypt (Aswan/Luxor) shift slightly later and tighter, about November through January. Start the longer winter/daikon types early in the window (October to November) so they finish before the spring heat arrives. Day temperatures in the 15-25 C range suit the crop's optimum of about 10-24 C; avoid sowing from late spring through summer (April to September), when sustained heat above about 21 C and long, hot days drive plants to bolt. Sow these larger daikon seeds deeper than salad radishes, about 2 cm deep, directly where they are to grow, since radish dislikes root disturbance and is not transplanted. Space winter/larger radishes about 15-20 cm apart (around 8-15 cm for daikon), with about 15 cm between rows. Choose an open, sunny site in full sun. Seedlings emerge in roughly 3-10 days, commonly 4-7 days in warm soil and up to 10 days in cool soil; radish will even germinate at soil temperatures as low as about 5 C.

Fertilizing

Prepare the bed with aged compost before sowing, then side-dress with more aged compost at midseason. Steer clear of fresh manure and high-nitrogen fertilizers, which push lush leafy top growth at the expense of the root you actually want. A balanced or low-nitrogen feed is preferred, and as a root crop the white radish responds well to a phosphorus-leaning blend such as 5-10-10.

Care

Consistent moisture is the secret to crisp, non-split roots. Keep the soil evenly moist for rapid, even growth, aiming for about 2.5 cm of water per week and soaking the bed thoroughly at least once weekly; sandy soils dry out faster and need watering more often than heavy clay. Irregular or stingy watering turns roots woody and hot-tasting. Thin the seedlings about a week after they emerge so the roots have room to swell, spacing daikon types about 5-10 cm apart or more. Grow in full sun, though light or partial shade can help reduce bolting in the warmest spells. Watch for flea beetles nibbling small holes in the leaves, cabbage root fly maggots tunnelling into the roots, slugs and snails on young seedlings, plus aphids and wireworms; floating row cover or fleece together with steady moisture helps keep flea beetle and root fly damage down. Daikon and winter types are ready in about 50-60 days, signalled by the root shoulders pushing up out of the soil. Harvest promptly, because over-mature roots turn woody, pithy and prone to splitting.