Horseradish is a large perennial herb with coarse leaves and small white flowers. The large taproots are harvested to make the pungent relishes and sauces for which the plant is known. Root cuttings or divisions planted in spring will produce harvestable roots in 180-240 days. The plant can become invasive, so plant it with caution, or keep it contained to prevent it from spreading too far.
Height: 1 t 3 feet
Widt: 24-36 inches wide
Special Features: Low Maintenance
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.
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.