How to grow horseradish
Overview
Horseradish is a hardy perennial herb grown for its pungent, spicy roots used in sauces and condiments. It is a vigorous grower that can become invasive if not contained, so plant in a dedicated bed or large container.
Varieties
- Maliner Kren — A German variety with high yield and strong flavour, well-suited to Australian conditions.
- Bohemian — A traditional variety known for its smooth, white flesh and pungent heat.
Soil Preparation
Horseradish prefers deep, loose, fertile soil with a pH of 6.0–7.0. Enrich with well-rotted manure or compost before planting. Ensure excellent drainage to prevent root rot; raised beds are ideal in heavy clay soils.
Growing Guide
Plant horseradish in full sun with well-drained, fertile soil. Space root cuttings 60 cm apart and 10 cm deep, with the crown at soil level. Keep soil consistently moist but not waterlogged; dry conditions produce thin, less pungent roots. For best flavour, harvest after frost has touched the leaves, as cold triggers root heat.
Care
Feed horseradish with a balanced organic fertiliser in early spring and again after midsummer. Cut back foliage in autumn to encourage root thickening. Divide and replant every 2–3 years to prevent overcrowding and maintain vigour.
Companion Planting
Horseradish pairs well with potatoes, fruit trees, and rhubarb, but avoid planting near brassicas (cabbage, broccoli) as it may attract shared pests. It also benefits from being grown near mint to deter some insects.
Common Pests & Risks
Flea beetles cause small holes in leaves; control with diatomaceous earth or neem oil. Caterpillars (cabbage white butterfly) can be hand-picked or managed with Bacillus thuringiensis. Root rot may occur in waterlogged soil; improve drainage.
Harvesting
Harvest horseradish roots in autumn after the first frost, when leaves begin to die back. Dig up the entire root system, selecting thick, healthy roots for use; replant small root pieces for next season's crop.
In the Kitchen
Grate fresh horseradish root for immediate use in sauces, or preserve in vinegar to retain heat. Store unpeeled roots in the fridge for up to 3 weeks; peel and grate just before use for best flavour.
Troubleshooting
Yellow leaves: overwatering or poor drainage; reduce water and improve soil. Thin roots: insufficient sun or overcrowding; thin plants and ensure full sun. Small roots: poor soil or competition; enrich soil and divide plants. Leaf spots: fungal disease; remove affected leaves and improve air circulation. No heat: harvested too early or in warm weather; wait for frost or cool season.