Horseradish is a hardy perennial usually grown as an annual for the pungent roots. These roots contain an oil that gives the roots a hot, biting, pungent taste. This sharp taste makes horseradish valuable as a condiment. Horseradish does not grow well in Florida, although gardeners do attempt to grow it. The best horseradish is grown in the northern section of this country and at higher elevations of the tropics.
Where horseradish is grown, two types are usually found: the common and the Bohemian. The common type has broad, crinkled leaves and high quality roots. The Bohemian type has narrow, smooth leaves, with root quality somewhat less than that for the common type.
Propagation is by vegetative means, utilizing side root cuttings called sets. Seeds are not used. The side roots (sets) are removed from the main central root when it is harvested. All small, slender root sets between 8 and 14 inches long and about the thickness of a pencil are removed, trimmed, and stored in a moist, cool place until time for planting in early spring.
Rows are spaced 30 inches apart and plants are spaced 2 feet apart in the row. A furrow 3–5 inches deep is dug in each bed. The sets are placed horizontally in the bottom of the furrow, and a little soil is placed on the bottom end of the root, leaving the top portion uncovered.
A special practice is utilized by horseradish growers to obtain top quality roots. When the largest leaves reach 8 inches long, the soil is dug away from the top end of the main root. While the lower end is left undisturbed, the top and middle portions are stripped of any small roots. Then the soil is replaced. A few weeks later, the practice of stripping is repeated. The result is a smooth root with few, if any, side roots to mar the appearance.