How to Grow Horseradish: Planting, Care & Harvest

Quick answer

Plant root cuttings 4–6 weeks before last frost (Purdue HO-186), or in early spring as soon as the soil is workable (UMN). Space sets about 1 foot apart; cover with 2–3 inches of soil (UMN). Harvest late October–early November or just before the ground freezes (UMN). Spreads aggressively — contain the bed.

Horseradish at a glance

PlantPlant root cuttings: 6–4 wk before last frost
SpacingUMN: space sets 1 foot apart; set vertically or at about 45°; cover with 2–3 inches of soil.
Days to harvestPerennial; harvest late Oct.–early Nov. (UMN)
-7-6-5-4-3-2-1LF+1+2+3
■ Start indoors   ■ Plant out   ■ Harvest
Weeks relative to last frost (LF). Colored weeks show when our ZIP planner schedules each step.
Jump to

Updated

Planting dates for your ZIP: the ZIP planting planner counts each window from your local frost dates.

Organic pests and diseases: see also organic pest control. Use any product as the label directs.

Spreads aggressively. Harvest thoroughly and contain the planting area so leftover roots do not take over (UMN).

Horseradish roots
Horseradish roots. Photo: San906, Wikimedia Commons, CC0 (resized).

Planting timing

Purdue HO-186: horseradish under hardy — plant 4–6 weeks before last spring frost (vegetatively propagated). (Purdue HO-186) UMN: “Plant root cuttings … in early spring as soon as the soil is workable.” Planner: Plant root cuttings last frost −6 to −4. (UMN horseradish)

Depth and spacing

UMN: space sets 1 foot apart; set vertically or at about 45°; cover with 2–3 inches of soil. Till about 8–10 inches deep before planting.

Sun, soil and water

UMN: deep, rich, moist loam; sunny site; avoid hard, shallow, stony soils. Compost or well-decayed manure before planting — omit printed synthetic rates. Fresh manure can cause forked roots and excess tops (UMN).

Care

Weed early; mulch. UMN quality method for home growers: lift and strip side roots twice (when the biggest leaves are about 8–10 in., then about 6 weeks later). Replant lateral cuttings; roots left two seasons become stringy. Contain the bed.

Harvest

UMN: late October–early November or just before the ground freezes. Dig a trench about 12–24 in. Spring harvest is OK if storage was poor — dig as new growth starts.

Pests and diseases

Horseradish flea beetle (UMN); cabbageworm / mustard leaf beetles (NC State); root rots (UMN). Cultural: disease-free cuttings; rotate the site; row cover on young foliage where practical. Prefer cultural controls this pass; use any product as the label directs.

Related: ZIP planner · organic pest control · all grow guides

Frequently asked questions

When do I plant horseradish?

About 4–6 weeks before last frost (Purdue), or early spring as soon as the soil is workable (UMN).

When do I harvest?

Late October–early November or just before the ground freezes (UMN).

Will it take over the bed?

It can. Harvest thoroughly and contain the planting area (UMN).

More grow guides: All grow guides

Sources