Horseradish
Armoracia rusticana
A hardy perennial in the cabbage family grown for its thick, fiercely pungent root used as a condiment. Vigorous and long-lived, it can become invasive once established.
- Light
- Full sun to partial shade
- Water
- Moderate; keep soil evenly moist
- Difficulty
- Easy
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Overview
Horseradish is a robust perennial valued for its long, white taproot, which releases a sharp, sinus-clearing heat when grated. The pungency only develops when the root cells are cut, triggering the release of mustard-oil compounds.
Easy to grow to the point of being weedy, horseradish persists for years because even small root fragments left in the soil will resprout. It is the source of prepared horseradish and an ingredient in wasabi substitutes.
How to identify it
- Large, coarse, wavy-edged basal leaves up to 60 cm (2 ft) long, somewhat dock-like
- Forms a leafy clump 60-120 cm (2-4 ft) tall
- Small four-petaled white flowers in branching sprays (it rarely sets viable seed)
- Thick, fibrous, white taproot with a fierce smell when cut
- Spreads by root fragments and lateral roots
Care & growing
Horseradish is nearly indestructible.
- Light: Full sun to partial shade
- Water: Moderate, even moisture produces the best roots
- Soil: Deep, loose, fertile soil lets the taproot grow long and straight
- Temperature: Very cold-hardy; dies back in winter and returns each spring
- Feeding: Light feeding; too much nitrogen makes leaves at the root's expense
- Propagation: From root cuttings; contain it, as it spreads readily and is hard to remove
Habitat & origin
Native to southeastern Europe and western Asia, horseradish has been cultivated since antiquity and has naturalized across Europe, North America, and other temperate regions.
It grows in moist, fertile soils in fields, gardens, ditches, and waste ground, tolerating a wide range of conditions.
Uses & benefits
Horseradish is grown almost entirely for its pungent root.
- Culinary: Grated root makes prepared horseradish, horseradish sauce, and cocktail sauce, and flavors many wasabi substitutes
- Medicinal: Traditionally used as a stimulant and for congestion and circulation
- Companion: Sometimes planted near potatoes as a reputed pest deterrent
The intense heat fades quickly once grated, so it is best prepared fresh and used soon after.
Frequently asked questions
Is wasabi made from horseradish?
Much commercial 'wasabi' is actually dyed horseradish, since true wasabi (Eutrema japonicum) is rare and expensive. The two are related plants with similar heat.
Why is horseradish so hard to get rid of?
Any small piece of root left in the soil can sprout into a new plant, so it readily regrows and can become invasive.
When should I harvest the root?
Roots are best dug in autumn or early spring when the pungency is strongest, after the plant has stored energy in the root.
Why does horseradish make my eyes water?
Cutting or grating the root releases volatile mustard-oil compounds (isothiocyanates) that irritate the eyes and sinuses, much like onions.
Horseradish guides
In-depth guides for identifying, growing, and caring for Horseradish.
