Horseradish grows well in zones 2-9. Horseradish need long growing seasons and winter temperatures cold enough to ensure above ground plant decay. It does best in full sun and soil pH range of 5.5 to 7. Additionally, it does not like to be kept in water logged soil, and does not require much watering. Water horseradish weekly in dry spells. Horseradish grows approximately 24" tall and 18" wide. The root should be dug out and divided after the first frost in the autumn kills the leaves a year after it has been planted (1). The main root is harvested and one or more large offshoots of the main root are replanted to produce next year's crop. Horseradish left in the garden can spread via underground shoots and become invasive. Older roots left in the ground become woody and no longer culinarily useful. Older plants can be dug and redivided to start new plants (2). Bohemian horseradish is more resistant to disease than common horseradish, but both varieties are usually unaffected. Horseradish attracts Small White Butterfly caterpillars, which will start appearing in gardens after the last frost and may become a problem through the remainder of the growing season. Handpicking is an effective control strategy to keep Small White Butterflies from infesting the horseradish and chewing large, ragged holes in the leaves (3). Horseradish couples well with strawberries or other shallow-rooted plants (4).
Culinary or Medicinal Uses
Horseradish is cultivated primarily for its large, white, tapered root; the term "horseradish" is often used to refer to the grated root of the horseradish plant mixed with vinegar. It can keep refrigerated for months but eventually will darken (indicating it is losing flavor). The leaves of the plant are edible but are not commonly eaten due to their bitter root flavor. It can be used as a main ingredient for soups (5). Horseradish contain significant amounts of cancer-fighting compounds which increase the liver's ability to detoxify carcinogens and may suppress the growth of tumors. Other health benefits include its ability to fight the flu, respiratory disorders, tonsillitis, and urinary tract infections. Roots can be used to externally treat joint discomfort (6).
Significance to Cultural Communities
Originating from Southeastern Europe and Western Asia, horseradish is popular in Ukraine, Poland, Lithuania, Russia, Hungary, Romania, Bulgaria, and Slovakia. Having this dish on the table is a tradition of the Christian Easter and Jewish Passover tradition in Eastern and Central Europe. It is an essential component of the traditional wedding dinner in Southern Germany (8). Both roots and leaves were used as a medicine during the Middle Ages and the root was used as a condiment on meats in Germany, Scandinavia, and Britain. It is used in the Japanese condiment wasabi. Horseradish with a little vinegar was commonly used among the Germans for sauce to eat fish and meats with. Cocktail sauce for shrimp and other seafood is prepared by mixing equal parts ketchup with horseradish.
1) Gerarde, John. “The Herball or Generall Historie of Plantes.” 1597. John Norton. London.
2) Pleasant, Barbara. "Horseradish. Mother Earth News: October-November 2003. http://www.motherearthnews.com/organic-gardening/grow-and-cook-with-horseradish-zmaz03onzgoe.aspx#axzz2yBBMJNG4
3) "Caterpillar Pests of Cole Crops in Home Gardens" by Suzanne Wold-Burkness and Jeff Hahn (University of Minnesota)
5) "Book of Herbs and Spices" by Carol Ann Rinzler
6) "History of Cultivated Vegetables" by Henry Phillips
7) "Horseradish: Protection Against Cancer and More" by Steve Goodm