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 location for plant carefully as it is hard to relocate once planted. It can also be planted in a very large pot. 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 hole 12″ deep and fill with compost. Plant root cutting 4″ – 5″ below the soil at a 45 degree angle and cover lightly with mulch. If planting more than one, space 30″ apart.
Remove weeds as plant emerges. Keep moist in late summer to prevent roots from drying out. Fertilize lightly as needed in the spring using a 5-10-10 balance. 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 through the 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 get spicier with storage.