Growing Black Radishes
Botanical Name: Raphanus sativus
Great fun to grow and wonderful to eat, the black radish is considered a specialty radish and so gardeners may have to search a bit to locate seeds. A work of art, really, the black radish should be a part of every gourmet garden.
The appearance of black radishes is much different than typical red, or “table,” radishes. Black radishes have skin that’s really close to black, and a matte surface rather than shiny. The flesh can be pure white or a creamy white.
In any case, the flavor is powerful and pungent, not as light as red or all-white radishes. In fact, the white flesh of black radishes is so strong that it is considered health food: a tonic for the liver. Imagine how good a slice of spicy black radish – raw – would taste along with a stein of beer!
Black radishes are also different from table radishes in that they have a longer growing season and are planted later in the year. With maturity ranging from 35 days to 55 days or more, black radishes are generally planted in summer for a fall harvest. And once mature, black radishes can stay good for long periods in the ground; if harvested in autumn, black radishes may be kept for months in a root cellar.
Here are some of the black radish varieties to look for:
- Round Black Spanish. In French they are called Noir Gros Rond D’hiver. A large radish that has been grown at least since the 1500’s, the Round Black Spanish may grow to five inches across. The almost nutty flesh may be eaten raw or cooked. The thin skin makes for dramatically colored round slices. Days to maturity: about 55.
- Long Black Spanish, or, in French, Noir Gros Long D’Hiver. Growing to an impressive nine inches long, this slender heirloom radish can be sown all the way into mid-autumn.The flesh packs some firepower.
- Round Black. A close relative to the Spanish black radishes, this American heirloom matures in about 35 days, so can be sown in early fall for quick harvest and subsequent storage. Grows to about four inches in diameter.
- Nero Tondo. Another black radish close to the Spanish black, this variation seems to resist hot-weather bolting better than any other. So if your weather heats up quickly in late spring, the Nero Tondo may be the best choice for consistent texture and flavor. Maturity in 50 days and can be considered a summer black radish.
- Russian Black. Native to the some of the coldest growing conditions imaginable, the Russian heirloom black radish can germinate at close to freezing soil temperatures and forms round mature roots in quite cold soil. In warmer zones, try sowing in fall and harvesting in spring.
Finding black radish seeds can be a challenge, so look online or in seed catalogs during the winter. Then place an order promptly and keep seeds in the refrigerator until you are ready to plant them.
Radish seed is sown directly into well-worked ground and covered with about ¼ to ½ inch of soil. Keep watered consistently.