(For details on growing many other vegetables and fruits, visit our Crop at a Glance collection page.)
Cold hardy, a perennial crop, and easy to grow in sun or partial shade, horseradish (Armoracia rusticana) quickly makes itself at home in gardens. Horseradish roots are harvested in fall, winter or spring, and then peeled and ground before being enjoyed as a peppery condiment.
Growing horseradish is easy in Zones 4 to 7, where established horseradish plants require little care. In addition to growing horseradish roots to eat, you can use horseradish as a medicinal herb for clearing a stuffy nose. Horseradish tea is sometimes used as a preventive fungicide on fruits and other plants plagued by fungal diseases.
Types of Horseradish
Horseradish leaves vary in their broadness. Older strains of common horseradish have leaves that are up to 10 inches across, whereas “bohemian” strains have narrower leaves. The latter is the type of horseradish that is commercially grown, so you are probably growing horseradish with Czechoslovakian heritage if you plant horseradish roots purchased at the store. The ‘Maliner Kren’ variety is of this type.
How to Plant Horseradish
Planting horseradish is best done is spring, whether you begin with crowns from a nursery, or a root from the supermarket. Most households harvest enough horseradish for their needs from two or three plants.
Set out roots or crowns a few weeks before your last frost date, in any fertile, well-drained soil. Horseradish grows best in moist, silty soils like those found in river bottomland, but enriched clay or sandy loam with a near neutral pH is acceptable. Situate horseradish roots diagonally in the soil, with the slanted end down and the flat end up.
For recommended planting dates for your local climate — and to design your garden beds — try our Vegetable Garden Planner.
Allow upright horseradish plants a full season to establish themselves in the garden. The long, strap-like leaves often grow 3 to 4 feet tall; they should not be fed to livestock or people, but make good compost fodder. Remove weeds that crowd the young plants. Growing horseradish plants develop most of their storage roots in early fall, so they should not be allowed to run dry in late summer.
Overwintered horseradish plants may send up spikes of white flowers in late spring. Clip off the seed heads before they become fully mature, because horseradish easily becomes weedy.
Harvesting and Storage
Your horseradish harvest should commence in late fall, after several frosts have damaged the leaves. Use a digging fork to loosen the soil on two sides of the plant, gathering up broken pieces of root as you dig. Then loosen the soil on the other side of the plant before attempting to pull it. Set aside or replant root pieces the size of a pencil, and store others in plastic bags in the refrigerator. Harvesting horseradish can continue into winter provided the ground is not frozen — or, you can dig the roots first thing in spring. Between diggings, keep fresh horseradish roots in the fridge, ready to use.
To prepare fresh horseradish for eating, peel a root and cut it into small pieces, then puree in a food processor with just enough water for chopping. Add a few pinches of salt and a teaspoon or two of white vinegar, and puree until only slightly lumpy. Place in a small clean jar, and add more vinegar if needed to cover the horseradish. Use within two weeks by mixing with mayo or sour cream to make horseradish sauce.
Horseradish roots often wander several feet from the mother plant, and sprout new plants from root buds. These can be dug and replanted in any season, or you can simply replant 3-inch pieces of horseradish root. Horseradish should be grown near the outer edge of the garden in a permanent patch, because it is difficult to eradicate once established. Even small pieces of horseradish root left behind in the soil after harvesting will grow into new plants.
For growing advice for many more garden crops, check out our complete Crops at a Glance Guide.
Contributing editor Barbara Pleasant gardens in southwest Virginia, where she grows vegetables, herbs, fruits, flowers and a few lucky chickens. Contact Barbara by visiting her website or finding her on Google+.