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Raphanus spp.

radishes

Brassicaceae

Eastern Mediterranean and Asia; long cultivated, with an uncertain wild origin

Attracts Pollinators Attracts Butterflies Container Friendly

SunFull Sun – Part Shade

WaterMedium

Overview

Raphanus spp. is a small genus of annual and biennial herbs in the cabbage family (Brassicaceae), the radishes, native to the eastern Mediterranean and Asia and grown around the world as a root vegetable. The cultivated radish R. sativus forms a rosette of rough, lobed leaves above a swollen root that may be round or long and colored red, pink, white, purple, or black, from the small salad radishes harvested in three to four weeks to the large winter and daikon types. If left to grow, plants send up branched flowering stems 1 to 3 ft (30 to 90 cm) tall bearing four-petaled white, pink, or pale-yellow flowers, followed by plump seed pods that stay closed at maturity. R. raphanistrum, wild radish, is a widespread weed of fields and roadsides with similar flowers and a slender, beaded pod. The genus grows fast in cool weather, and warm temperatures and long days push the plants to bolt and flower, which turns the roots woody and sharp. Radishes are grown as a quick spring and autumn crop and as a cover and trap crop on farms.

Native Range

The cultivated radish has been grown for so long that its exact wild origin is uncertain, but the genus is native to the eastern Mediterranean, the Middle East, and central and eastern Asia. Wild radish has spread as a weed across temperate regions worldwide, including much of North America.

Suggested Uses

Raphanus spp. is grown as a fast root vegetable in kitchen gardens, raised beds, and containers, and as a quick catch crop between slower vegetables. Radishes are sown to mark rows of slow-germinating seeds and as a cover and forage crop that loosens soil with its roots. The flowers and young seed pods of some types are also eaten, and bolted plants draw pollinators.

How to Identify

Identify Raphanus spp. by its rosette of rough, bristly, lobed leaves and, in the cultivated radish, the swollen edible root at the base. The four-petaled flowers form a cross typical of the cabbage family, in white, pink, or pale yellow, often with darker veins. The seed pod is a plump, spongy capsule that does not split open, which separates Raphanus spp. from many other mustards.

Appearance

Size & Dimensions

Height6" - 3'

Width/Spread6" - 1'6"

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Flowering follows bolting, mostly in late spring and summer as days lengthen and temperatures rise. The branched stems carry loose clusters of four-petaled flowers over several weeks, drawing bees and hoverflies. Seed pods swell soon after and ripen as the plant dies, in the annual types within a single season.

Detailed Descriptions

Flower Description

white, pink, or pale yellow with purple veins

Foliage Description

green

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 5-8 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 7.0(Neutral)

357912

Soil Types

loam sand

Drainagewell drained

Water & Climate

Water Needs

Medium

Care & Maintenance

Care Guide

Raphanus spp. grows in full sun and loose, fertile, well-drained soil at a pH of about 6.0 to 7.0, with steady moisture for tender, evenly formed roots. Seed is sown directly where plants are to grow, in early spring and again in late summer for an autumn crop, since the plants do not transplant well. Cool weather suits the genus, and summer heat and long days cause early bolting, woody roots, and a hot, pithy texture. Even watering keeps the roots from cracking or turning sharp, and thinning the seedlings gives each room to swell. Most radishes mature quickly, from about three weeks for small types to two months for winter kinds. Flea beetles, root maggots, and club root are the main problems, all shared with other brassicas.

Pruning

Radishes are not pruned. Thinning the young seedlings to 1 to 2 in (2.5 to 5 cm) apart gives each plant room to form a root. Pulling the roots promptly once they reach full size keeps them crisp, as radishes left in warm ground quickly turn woody and split.