Horseradish is a tough, cold-hardy perennial that US gardeners grow for its thick white taproot, which releases a sharp, sinus-clearing bite the moment it is grated. Plant it once from a pencil-thick root cutting and it will return year after year, often spreading enthusiastically. A single plant can supply a family with enough grated root and homemade sauce for a whole winter.

When and how to plant

Set root cuttings out in early spring, a couple of weeks before the last frost, as soon as the soil can be worked. It is grown from root cuttings or crowns rather than seed, so there is no indoor start; lay each cutting at about a 45 degree angle with the top a few inches below the surface. Give it full sun and deep, loose, well-drained soil that has been dug and loosened at least a foot down so the roots can grow long and straight.

Care

Keep the soil evenly moist during the growing season, since steady water produces plumper, milder roots and prevents woodiness. Horseradish is not a heavy feeder, but a modest dose of balanced fertilizer or compost worked in at planting is plenty. Space plants 18 to 24 inches apart, and because it can spread aggressively, many gardeners confine it to a dedicated bed, a buried bottomless container, or a raised bed to keep it in bounds.

Common problems

Horseradish is largely trouble-free, but it can attract flea beetles and cabbage worms that chew small holes in the leaves, along with occasional aphids. Row covers early in the season and simply removing damaged leaves usually keep foliage pests in check. In poorly drained soil the roots can rot, so the best prevention is loose, well-drained ground and avoiding waterlogged spots.

Harvest

Harvest in late fall after several hard frosts, which sweeten and intensify the root's flavor, typically about five months after spring planting. Loosen the soil deeply with a fork and lift the main taproot, pulling up as much of the long root as you can. Leave some smaller side roots in the ground and they will regrow the following year for a continuous supply.

Growing Horseradish in containers

Horseradish grows well in a deep container, which also makes its spreading roots easier to manage. Use a pot at least 18 to 24 inches deep and 12 to 18 inches wide with drainage holes and loose, fertile potting mix. Keep the soil evenly moist, feed once in spring, and harvest roots in fall after frost, leaving a root piece to regrow if desired.

Watering & feeding Horseradish

Provide about 1 inch of water per week from rain and irrigation, increasing slightly in hot, dry weather. It has average water needs once established, but drought can make roots smaller and tougher. Water deeply at the soil level to encourage roots to grow down, and use mulch to hold moisture and limit weeds. Water in the morning when possible, and watch for wilting or dry, cracked soil as signs of drought, while persistently soggy soil and yellowing can signal overwatering.

Horseradish is a moderate feeder that benefits from compost or well-rotted manure worked into the bed before planting. Phosphorus and potassium support root development, while nitrogen should be moderate rather than heavy. Work organic matter into the soil before planting, then side-dress lightly with a balanced garden fertilizer or compost after plants are established if growth is weak. Avoid repeated high-nitrogen feedings later in the season, since they can favor leaves over roots. Keep the bed evenly moist during the first weeks after planting. Do not let roots sit in poorly drained soil, especially through cool or wet periods.

Saving Horseradish seeds

Horseradish is normally propagated from root cuttings, not seed, because seed-grown plants may be variable and named selections are not reliably maintained that way. If an open-pollinated plant flowers and sets mature dry seedpods, let the pods dry on the plant, collect them before they split, and thresh out the seeds. Dry the cleaned seed thoroughly indoors and store it in a cool, dry container, but expect variable offspring and note that F1 hybrids do not come true. Horseradish seed is rarely saved, and its storage life is roughly 3 to 5 years under good conditions.

Horseradish companion plants

Horseradish is best treated as a vigorous, separate perennial crop, with shallow-rooted annual flowers such as sweet alyssum at the edge if space permits. Its large leaves can provide some soil shade, but strong evidence for crop-specific beneficial pairings is limited. Avoid planting it beside other brassicas such as cabbage, broccoli, kale, or radish because they share flea beetles and several diseases, and keep it away from beds where its spreading roots would compete with other vegetables.

Frequently asked questions about Horseradish

General guidance for US home gardens. Reference figures are typical values; your exact timing depends on your local frost dates and variety. Page updated Aug 4, 2026.