A robust vigorous perennial with long fleshy taproots and large bright green leaves. The roots are prized for their pungent hot, peppery flavour.
Family: Brassicaceae
Botanical Name: Armoracia rusticana
Common Names: Horseradish, pepper root, pepper turnip, red cole, mountain radish, great raifort.
Foliage: Deciduous, large, coarse, dock-like leaves.
Flowers: Loose panicles of small white or pale pink flowers.
Flowering Period: Early Summer.
Soil: Well-drained, fertile soil (chalk, clay, sand or loam). Acid, alkaline or neutral pH.
Conditions: Full sun or partial shade. Best planted in a west or south facing aspect.
Habit: Upright, spreading.
Type: Herbaceous perennial.
Origin: Europe.
Hardiness: Fully hardy in the UK.
Easy to grow. Thrives in any good, deeply cultivated, moisture-retentive soil, in sun or dappled shade.
Horseradish can quickly become invasive so you will need to restrict the root run, usually by growing in a large deep container. Alternatively, they can be grown as an annual crop by digging up all the roots in autumn and storing in damp sand. Use the larger roots in the kitchen as required and replant the smaller roots in spring.
Water freely in summer. Control spread of established plants by digging out wayward roots.
Cut down foliage once flowering has finished in autumn.
Prone to club root.
Sow or plant in spring. Plant roots in early spring. Planting depth 6in (15cm), spacing 2ft (60cm).
The young leaves are sharp, hot and spicy. Mild in spring but fiery in autumn. The thick, white fleshy root can be peeled and grated (or crushed) to produce a hot seasoning to flavour sauces and dips.
Tip: Like onions, grating horseradish can make your eyes water, so protect your eyes with swimming (or other tight fitting) goggles to reduce irritation when grating.
The grated root can be mixed with a little vinegar and thick cream to make horseradish sauce - a traditional accompaniment to roast beef or smoked mackerel.
Harvesting Horseradish: dig up the roots as required in autumn and either use straight away or store in damp (but not wet) sand until needed.
Horseradish is usually sold as Thongs (roots or bulbs) in the spring (usually around end March).
Armoracia rusticana is the main strain, which produces rough, wavy-edged or lobed, dark green leaves and small white, flowers in early summer. Long yellowish-buff tap roots with white core. Height to 3ft (90cm). For sale at Crocus.