Armoracia rusticana (Horseradish)

Horseradish (Armoracia rusticana) is a vigorous, hardy perennial herb grown for the hot and pungent flavor of its roots. Easy to grow, it has been a culinary favorite since antiquity.

What is Horseradish?

• Horseradish is a member of the Brassicaceae or cabbage or mustard family, which includes broccoli, cabbage, cauliflower, radishes, kale, and collard greens.
• It is native to southeastern Eastern Europe and western Asia and has been cultivated for over 3,000 years. Today, it is grown worldwide.
• This plant should not be confused with Japanese Horseradish or wasabi (Wasabi japonica), a totally different plant.
• Horseradish is a rhizomatous perennial with large, dock-like, bright green leaves and small, white flowers in early summer.
• It is grown for its hot, pungently aromatic fleshy root, used as a condiment or table relish. The root is carrot-like, white to cream-colored, and usually rough.
• This root vegetable may grow up to 3 feet (90 cm) tall and wide.
• The plant is highly vigorous, spreading by underground shoots and out-competing most other plants. It can become invasive if the roots are not harvested every year.
• Planted in early spring or late fall, Horseradish thrives in colder environments and tolerates frost.
• Horseradish contains compounds that may provide health benefits. Add it to your diet and enjoy it in sauces or as a condiment with fish, meat, and strong-flavored vegetables.
• While the leaves are edible (raw or cooked), they are rarely consumed.

Horseradish Health Benefits

• While Horseradish makes a flavorful addition to various dishes, it can also provide some health benefits.
• Since it is usually consumed in small quantities, it is low in calories but contains small amounts of calcium, potassium, iron, magnesium, and vitamin C.
• It also contains compounds that may protect against cancer by restraining the growth of cancer cells and promoting their death.
• Horseradish root is rich in antioxidants that help fight cell damage caused by harmful free radicals.
• Some studies also suggest that Horseradish may prevent the development of colon, lung, and stomach cancer.
• The oil released when the root is cut may have strong antibacterial properties and fight E. coli, H. pylori, and Salmonella.
• Horseradish is often used to fight colds and breathing issues. Beyond the burning sensation in our nose, throat, and sinuses when you eat Horseradish, the plant may help your respiratory health.
• Nutrition Facts (per 1 tablespoon): 7 calories, 1.7 grams carbs, 0.2 grams protein, 0.1 grams fat, 0.5 grams fiber.

Growing Horseradish

• Horseradish grows up to 24-30 in. tall (60-75 cm) and 30-36 in. wide (75-90 cm).
• The plant performs best in full sun in light, fertile and deep, moist but well-drained soil with a pH between 6.0 to 7.5. It will tolerate partial shade but will not produce as well.
• Before planting, spade or rototill the soil to a depth of 8-10 inches (20-25 cm).
• Horseradish has a long growing season and takes about 140-160 days to harvest.
• This root vegetable grows best at cool temperatures around 60-65°F (15-18°C).
• It will tolerate a low temperature of 45°F (7°C) and grow poorly above 75°F (24°C).
• Horseradish can be grown by seed, but it is far easier to purchase horseradish sets (small pieces of the root) from the nursery.
• This perennial herb is an easy plant to grow that will take over your garden in no time. Try to plant it away from most plants and consider planting it in containers or raised beds.
• The roots can be planted as soon as the soil is workable in early spring.
• Place the roots in the ground at a 45-degree angle, with the top of the root at or slightly below the soil level. Plant 12-18 inches apart (30-45 cm).
• Keep the plant well-watered during the growing season.
• Fertilize at the time of planting and then every four weeks. You can use compost or a balanced (10-10-10) vegetable fertilizer.
• To stimulate root production, once a generous amount of leaves appear above the soil, trim them back so that only a few are left for each plant.
• Practice crop rotation: do not plant in the same place more often than every three to four years.

Harvesting and Storing Horseradish

• Horseradish has a long growing season and takes about 140-160 days to harvest.
• The root is best when harvested in the fall. Its flavor is much more intense after frost, so consider harvesting earlier if you prefer a milder flavor.
• Dig carefully to avoid damaging the roots.
• Harvest the main root and replant the offshoots. Year-old roots have the most flavor.
• The replanted roots will sprout back into growth in spring, with a flush of new leaves.
• If your spring-planted roots are not ready to harvest by the first fall, you can dig them the following spring or fall.
• Harvesting some of the roots each year helps control this vigorous plant’s spread.
• Horseradish roots are best used fresh. If your harvest is generous and you have too many, you can wash, grate and dry your Horseradish.
• Alternatively, store the roots until you want to use them: bundle them together in a wooden box or tray and cover them with damp sand, then place them in a cool, dark, and frost-free place.

Pests and Diseases

Horseradish is not affected by serious pest or disease issues. It is deer-resistant.

• Pests: Keep an eye out for aphids, cabbageworms, cutworms, flea beetles, and wireworms.
• Diseases: Root rot may occur in soggy soils.

Companion Planting

• Horseradish is an excellent companion plant for fruit trees such as Apple, Apricot, Cherry, Nectarine, Peach, Pear, and Plum trees.
• Horseradish is a plant that will also help potatoes. It can deter the blister beetle and help deter the Colorado potato beetle. Horseradish also improves the potatoes’ resistance to disease. Do not plant it too close to your potatoes, though, as Horseradish grows too quickly to make an effective companion. You may want to plant it in a large pot that can be located near your potatoes.