Plant horseradish in sandy loam soil with good drainage. Till the soil about 8-10 inches and mix in a lot of compost or a complete garden fertilizer at a rate of one pound per 100 square feet. Use planting stock from root cuttings trimmed from main roots at harvest. Use root pieces ½ inch in diameter and 8-12 inches long. Plant in rows 30 inches apart with 15-20 inches between plants, usually in early April. Cover the roots with 2-3 inches of soil. Control weeds with cultivation or add mulch around each plant. About a year is needed to produce a crop. The plants make the greatest growth in late summer or early fall. Harvest is usually delayed until early November.

Harvest by digging a trench 12 inches deep along one side of the row. Work from the opposite side of the row with a shovel and use the tops as a handle for pulling them laterally from the soil. Leave one inch of green on the tops and remove side and bottom roots. Save those roots that are 8 inches and longer for next year’s planting stock. Cut the roots square across the top and sloping at the bottom to distinguish which end to set upright at planting time.

Storing Horseradish—In-Ground or Out

Tie cleaned root cuttings in bundles and place them in moist sand. Put them in a root cellar or basement at 32-40 degrees Fahrenheit. Do not expose the roots to light, as they will turn green. Roots may also be harvested in the spring rather than fall. Dig the roots as soon as new growth starts in spring. Roots left in the soil for two growing seasons become woody and stringy.

Horseradish may be kept for up to 10-12 months at 32 degrees Fahrenheit with relative humidity of 90-95%. Perforated plastic bags will help maintain high humidity. Roots dug when plants are actively growing do not keep as well as those conditioned to cold weather before they are dug. Inspect the roots frequently and discard injured or rotten roots.

Root rot is an occasional problem of horseradish. Use disease-free root cuttings as planting stock. Rotate the planting site so horseradish is not grown in the same place more often than 3-4 years. The horseradish flea beetle is a serious pest. It lays eggs on the leaf petiole and the larvae burrow into the petioles and kill some of the leaves. Good sanitation will help prevent insect problems.