Introduction

A member of the Brassica family, the radish is also related to the daikon.  The radish is thought to be native to Asia, but domesticated in the Mediterranean.  By 500 BC, the radish was grown in China and reached Japan 200 years later.  Wild forms have been found in China and the Middle East; but, in ancient times, the small radish was cultivated in Japanese and Chinese gardens as decorative plants. The radish reached Britain in the mid-16th century.  About the same time, Spanish and Portuguese colonists were introducing it to the New World, where Florida is now the leading producer. 

Radish is a cool-season root crop that matures to marketable size in 24 to 30 days under favorable weather conditions.  The mild to hot rootlets have proven tolerant of a wide range of climates and soils and can be grown and harvested year round.  The best quality roots are produced in spring or fall when temperatures are in the range of 50°F to 65°F, when daylength is short to moderate, and when grown with ample moisture. As temperatures increase and as the days become longer during summer (>15 hours), radish tends to bolt (go to seed) and the roots become pithy and pungent. To minimize the adverse effects of summer, maintain a high level of soil moisture.

As with any Brassica member, mustard oils are responsible for the tangy taste of radishes.  The outdoor varieties contain a greater concentration of them than those grown under glass or in hothouses.  Radish greens can be eaten as well, although most people toss them out.  Just like carrot tops, radish greens can be used in a variety of dishes, including raw in blended drinks or in salads.  They can also substitute for arugula.  Daikon cress is a sprouting vegetable grown from the seeds of white radish or daikon, and tastes like the more familiar garden cress and used in the same way; but it should never be cooked. (adapted from Innvista.com)

Types and Varieties

The names of different types can be confusing, particularly as the term "winter radish" is often applied in a nonspecific way.  The small table radish might be mistaken for the dwarf form of the black or winter radish.  In fact, they are different varieties of the same species.  The table radish is usually round; but it can also be ovoid, cylindrical, or turnip-like in shape.  They can be the familiar red or white, red and white mix, pink, purple, and black; but the flesh is almost always white.  However, there are some stunning varieties that have produced such dramatically-coloured flesh as black and white stripes or red, green, purple, or fuchsia. 

Daikon is a general term for a group of long, white radishes which need cool temperatures and shorts day-lengths to flourish.  Some of these can grow up to eighteen inches long and weigh about three pounds on average, but can reach almost fifty pounds.  While the flesh is juicier and hotter than the red globe, daikons are not as pungent as the Black Spanish.  Typical varieties are stubby and green-skinned with white tips that are very solid and extremely juicy and have sweeter flesh than the all-white daikon.  Chinese varieties may be green, pink, red, white, or colours in between and usually resemble fat carrots, although a rounded turnip form is also common. 

The black or winter radish is intensely hot.  The tuber of this biennial plant is formed from the basal part of the main shoot and a portion of the root.  Depending on variety, it can be round, bung-shaped, spindle-shaped, cylindrical, or oval.  Its lengths can range between four inches and a foot, and sometimes greater.  Skin colour can be white, pink, red, brown, and purple to black, as well as red and white.  Sprinkling salt over the radish slices or heating them takes some of the edge off the flavor.  They are best eaten raw in a sandwich or in salads.