For gardeners in a hurry to eat the "roots" of their labor, no better vegetable crop exists than radish. Spring varieties are ready to harvest in as little as three weeks after sowing seeds. Most of the later varieties take only four or five weeks from planting to harvest. Whatever a gardener's level of patience, March and April are ideal times to sow radish in Missouri.
Radish is a member of the Brassicaceae, or mustard, plant family which includes many familiar vegetables such as cabbage, broccoli, cauliflower, etc. The common name radish is derived from the Greek word Rhaphanus. The latter means "quick appearing" or, more loosely translated, "easily reared".
Radish is believed to have originated in China and is one of the oldest cultivated vegetables. Records indicate that Ancient Egyptians grew radish before the time the pyramids were built. The Greeks valued radish as both a food and medicine. Their high esteem for the vegetable led them to make small gold replicas of radish. Later, the Romans reportedly grew several types of radishes, several of which were similar to the ones we grow today.
Although large types of radish were introduced earlier, the small, Oriental types did not find their way to Europe until the 16th century. Columbus and his fellow explorers are credited with introducing radish to the Americas. It also was among the crops grown by the first English colonists to our country.
Most people think of radish being eaten raw out-of-hand or in a salad. However, in other parts of the world different types of radish are used in many ways. For example, varieties of radish have been developed from which only the leaves are consumed. Other varieties have been developed for their long seed pods which are eaten. In the Orient, radish is often eaten after being pickled in brine. Additionally, certain types of radish are grown for livestock feed while others have oil-rich seeds.
The rapid-maturing radish for the spring garden are those early varieties which usually have white flesh surrounded by red skin. One of the most popular early varieties is Cherry Belle. It is round, red and ready to eat in about 24 days following planting. Champion and Sparkler are also excellent variety for sowing in early spring. Both are bright red and ready to eat in about three weeks after seeding.
While other good red, round varieties exist, there also are several very useful white types. Snow Belle is very similar to Cherry Bell other than its skin is white instead of red. White Icicle is an excellent older variety with white skin and an elongated root not unlike that of a small carrot. A rapid grower, White Icicle requires about a week to 10 days longer to mature than other early types.
For those who like the unusual, there are newer varieties of radish that come in different colors. Black Spanish has white flesh surrounded by dark, blue-black skin. Easter Egg, another newer variety, produces small oval roots in several skin colors including pink, red, purple, violet and white. Regardless of the skin color, the flesh of Easter Egg is white.
Perhaps the most unusual of all radishes is the Chinese heirloom variety Watermelon. It produces roots that are white on the outside with pale green tops. The flesh of Watermelon closest to the root's exterior is white and becomes deep pink or red toward the interior. Depending on when they are harvested the roots can grow to the size of a softball.
Radish is a frost-hardy vegetable that needs cool temperatures to grow best and have the best flavor. Radishes grown in warm/hot weather become pungent or "hot" with age. The latter is due to compounds called allyl isothiocyanates which also are present in horseradish and mustard.
Seeds of radish germinate when soil temperatures are above 45 degrees F. In southern Missouri planting may be started in early March. Mid-March is a target planting date for radish in central Missouri while in northern Missouri, planting can be delayed until late March. Later planting can be done, but the risk of roots developing pungency increases when planting is delayed.
Seeds of radish may be planted up to ½ inch deep and plants thinned to about one inch between plants within rows. Planting wide rows 8 to 12 inches across is a space-saving way to grow them. To have too many radishes maturing at one time, sow small quantities of seeds at weekly intervals. Roots that are not harvested promptly after maturing tend to become pithy and loose quality.
Since radishes germinate and mature quickly, some gardeners include a few radish seeds in plantings of vegetables such as beets, carrots and Swiss chard. The radishes will help mark the rows of the vegetables slower to germinate and, later, provide extra produce for the family table.
The main insect pests of radish includes aphids and flea beetles. If they become too problematic, insecticidal soaps or other pesticides may be applied to control them.
A frequent complaint from gardeners is their radish have huge, lush leaves but roots that are too small to eat. Most often, this condition is the result of over-fertilization with nitrogen, or planting the radish too late so that hot weather arrives before roots are formed. Radishes will produce a better crop in soils that are not overly fertile. Also, avoid using fertilizers high in nitrogen on soils destined to be planted to radish. A fertilizer high in phosphorus such as superphosphate or bone meal will bolster root development. Additionally, loose, porous soils also allow for rapid root growth and the development of radishes with good size and shape.
Although not quite the nutritional powerhouses that some vegetables are, radish is a good source of vitamin C and contains other essential vitamins, minerals and dietary fiber as well. The average radish contains only 16 calories, making it a good choice for weight watchers.
REVISED: February 21, 2017