Armoracia rusticana is a cold hardy perennial member of the Brassica family. Native to Southeastern Europe and Western Asia, it can grow up to 3′ tall and is cultivated for its flavorful root. Horseradish root can be grated and mixed with vinegar to preserve its spicy flavor.
Determine the location for planting carefully as it is hard to relocate once planted. It can also be planted in a very large pot, which for some may be preferable as it spreads rather rapidly. Horseradish prefers sun but can also handle partial shade to retain moisture. Soil preference for horseradish has neutral pH and is moist and silty with good drainage.
Plant root cutting in spring as soon as soil can be worked. Dig a hole twelve inches deep and fill with compost. Plant your root cuttings four to five inches below the soil at a 45 degree angle and cover lightly with mulch. If planting more than one, space thirty inches apart.
Remove weeds as your plants emerge. Keep moist in late summer to prevent roots from drying out. Fertilize lightly as needed in the spring using a 5-10-10 fertilizer. Most root development occurs in the cooler fall months.
Some recommend allowing an entire year for establishment prior to harvest. Harvest the roots after frost has killed all of the leaves back in the early winter. Leave smaller roots behind to continue growth the following year.
Curing and Storage
After harvest, clean the roots and keep them covered (in a plastic bag with small holes) in the refrigerator. Roots should stay fresh for 4-6 weeks and will get spicier with storage.