Common Name: radish
Native Range: Garden origin
Zone: 2 to 11
Height: 2.00 to 3.00 feet
Spread: 1.00 to 2.00 feet
Bloom Time: Flowers not showy
Bloom Description: white to pale violet
Sun: Full sun
Suggested Use: Annual, Vegetable
Raphanus is a genus within the flowering plant family Brassicaceae. Two or three species are currently classified in Raphanus. They include the cultivated radish, Raphanus sativus and the common wild radish or jointed charlock, Raphanus raphanistrum. Some authors accept the podding or rattail radish, Raphanus caudatus as a third member of the genus, while others treat it as a variety of R. sativus. Substantial numbers of other species in the genus have been proposed at various times, but almost all are currently regarded as varieties of R. sativus, while a few are treated as varieties of R. raphanistrum or are not accepted as well-described species.[clarification needed] Examples are R. raphanistrum ssp. landra and R. raphanistrum ssp. maritimus (sea radish).
Raphanus species grow as annual or biennial plants, with a taproot which is much enlarged in the cultivated radish. Unlike many other genera in the family Brassicaceae, Raphanus has indehiscent fruit that do not split open at maturity to reveal the seeds.
The genus is native to Asia, but its members can now be found world wide. Growing wild, they are regarded as invasive species in many regions.
Raphanus species are used as food plants by the larvae of some Lepidoptera species, including cabbage moth, Endoclita excrescens, the garden carpet and the nutmeg.
Best grown in full sun in loamy or sandy soils. Can be seeded directly in two-week intervals between mid-April and the first of May for a spring crop and in the month of August for a fall crop. Radishes become tough and develop a hotter taste as they become older. Harvest when young before radishes bolt and become woody.
Daikon radishes (R .s. Longipinnatus Group) are best planted in July and August when soil temperatures are above 60 degrees F and the radishes have an opportunity to mature by fall. Sow seeds in full sun directly into the garden 1/4 to 1/2" deep, firming the soil somewhat after planting. Thin to 4 or 6" apart to ensure adequate room for root development. Before sowing, be sure the soil is cultivated and loose as deep as the radishes will be long. Raised beds are ideal for long radishes. Keep well fertilized and watered to insure mild flavor and tenderness.
Radishes have had a long relationship with man. Southern Asia is believed to be the country of origin since truly wild forms have been found there. Middle Asia and India appear to be secondary centers where many different forms developed subsequently. Third-century B.C. Greeks wrote of their radishes, and by 100 A.D., Roman writers described small and large types, mild and biting varieties, and round and long forms. A German botanist in 1544 reported radishes of 100 pounds. Radishes appear to be one of the first European crops introduced into the Americas, closely behind the arrival of Columbus. The white daikon (“big root” in Japanese) is common in Japan, and gardeners in increasing numbers are growing it here. The daikon has a milder, sweeter flavor than ordinary radishes. The root shape of all varieties is either long and cylindrical or short and round. The cylindrical roots range from 6" to 2' long and are either tapered or blunt at the end. The round varieties are the size of a baseball.
Flea beetles can be a problem as well as other pests typically found on Brassicaceae crops. Floating row covers can be very useful.
Raw, cooked or pickled.