Name: horseradish (Armoracia rusticana).
Height: up to 1.2m.
Plant type: herbaceous perennial.
Climate: cool and warm temperate, sub-tropical.
Soil: moist, deep and well-drained.
Position: full sun to part shade.
Foliage: broad, green with wavy margins.
Flowering and fruiting: small white flowers appear from mid-summer to mid-autumn.
Feeding: a light dressing of slow-release organic fertiliser in spring.
Watering: water regularly over summer to keep the soil moist.
Horseradish is easy to grow, but you need to give it its own permanent patch or pot as it spreads and can become a bit weedy if allowed – although that’s not necessarily a bad thing, especially if you love horseradish. The foliage is made up of large crinkly leaves with wavy margins, and grows vigorously over spring, summer and autumn. It dies back completely in winter, but reshoots in spring. The leaves are edible raw or cooked, but are typically ignored in favour of the pungent roots.
The roots are long, fleshy and white-cream coloured, growing up to 60cm long and 5cm thick. They give off a strong spicy aroma when broken or crushed.
Horseradish is grown by root cuttings or divisions – you will rarely find seeds available.
Roots can be freshly sliced or grated and added to sauces or cooked dishes. Use it to flavour protein or vegetable recipes, where a rich spiciness is desired. Add it last to a hot dish as the heat can dissipate the pungency.
The best time to plant is in spring or autumn. Horseradish is a vigorous spreader, so it’s best to give it a permanent spot in the garden or keep it contained in a large pot. Choose a warm, sunny spot with well-drained soil. Add well-rotted organic matter and dig in deeply, turning over the soil to help loosen it up for planting. In pots, use a top-quality potting mix.
To plant root cuttings, place the segments vertically or at a 45-degree angle and cover with soil. To plant crowns or root divisions, set them vertically, with the growing top or ‘eye’ just protruding above the soil surface. Gently water in well and keep the soil moist until the leaves appear.
If planting a few plants, space cuttings or crowns at least 30–50cm apart to allow for adequate growth.
Horseradish is a thirsty plant, so needs regular watering to keep the soil moist. Additional watering may be required in summer. Other than that, it’s fairly low maintenance. As a herbaceous perennial, it grows vigorously during the warmer months but dies back completely in winter. Winter is the ideal time to lift and divide the entire clump. Use a sharp knife or a sturdy spade to divide it and replant in other parts of the garden.
To remove it permanently, you need to get rid of all the roots. Horseradish regrows easily from root fragments buried in the soil, so it’s important to be thorough.
Water regularly to keep the soil moist. If allowed to dry out, the roots may split. Spread a thick layer of organic mulch over the soil surface and this will also help conserve moisture and suppress weeds, too.
Horseradish needs little in the way of fertiliser, especially if the soil has been improved with organic matter at planting time. However, a light dressing of blood and bone in spring will promote robust growth.
Individual roots can be harvested from autumn to spring. Use a garden fork to loosen the soil and gently lift and divide the whole clump. You can replant any surplus offcuts. Horseradish can be stored for a couple of weeks in the crisper; alternatively grate it and store in the freezer for up to six months.
Use the leaves in moderation to add a spicy bite to salads and side dishes.
Protect plants from snails and slugs with physical traps or scatter baits around pots and garden beds.
Horseradish only grows from root cuttings or root divisions.
After applying fertiliser, delay harvesting for a few days and rinse fruit well before cooking and eating. If using products to deal with pests, diseases or weeds, always read the label, follow the instructions carefully and wear suitable protective equipment. Store all garden chemicals out of the reach of children and pets.
Rocket: a peppery leafy green that’s ideal for spicing up salads.
Chilli: varieties to suit all heat levels, perfect for pots and garden beds.
Swede: a sweet, mellow root vegetable that also requires little care.
Check out our huge range of plants now and get your garden growing!
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