From the family Cruciferae.
Native of Europe naturalized in Britain and North America. Originally the horseradish was cultivated as a medicinal herb. Now it is considered a flavoring herb. The common name means a coarse or strong radish, the prefix horse often being used in plant to donate a large, strong or coarse plant. In the 16th century it was known in England as Redcol or Recole. In this period the plant appears to have been more popular in Scandinavia and Germany, where they developed its potential as a fish sauce. In Britain horseradish has become strongly associated with roast beef.
Species
Armoracia rusticana (Cochlearia armoracia)
Horseradish
Hardy perennial. Ht 60- 90cm (24-35in), spread infinite! Flowers white in spring (very rare). Leaves large green oblongs. The large root, which is up to 60cm (24in) long 5cm (2in) thick and tapering, goes deep into the soil.
Armoracia rusticana 'Variegata'
Hardy perennial. Ht 60- 90cm (24-35in), spread also infinite. Flowers white in spring (rare in cool climates). Leaves large with green/cream variegation and oblong shape. Large root which goes deep into the soil. Not as good flavor as A. rusticana.
Cultivation
Propagation
Root Cuttings
In early spring cut pieces of root 15cm (6in) long. I'm them either directly into the ground, at a depth of 5cm (2in), at intervals of 30cm (12in) apart, or start them off in individual pots. These can then be planted out when the soil is manageable.
Division
If you have a perpetual clump it will need dividing; do this in the spring. Remember small pieces of root will always grow, so do it cleanly, making sure that you has collected all the little pieces of root. Replant in a well-prepared site.
Pests and Diseases
Cabbage white caterpillars may feed on the leaves during late summer. The leaves may also be affected by some fungus diseases but this should not be a problem on vigorous plants and should be simply removed and burnt.
Maintenance
Spring: Sow seeds. Plant cuttings in garden.
Summer: Liquid feed with seaweed fertilizer.
Autumn: Dig up roots if required when mature enough.
Winter: No need for protection, fully hardy.
Garden Cultivation
Think seriously if you want this plant in your garden. It is invasive. Once you have it, you have it. It is itself a most tolerant plant, liking all but the driest of soils. But for a good crop it prefers a light, well-dug, rich, moist soil. Prepare it the autumn before with lots of well rotted manure. It likes a sunny site but will tolerate dappled shade.
If large quantities are required, horseradish should be given a patch of its own where the roots can be lifted and the soil replenished after each harvest. To produce strong, straight roots I found this method in an old gardening book. Make holes 42cm (15in) deep with a crow bar, and drop a piece of horseradish 5-8cm (2-3in) long with a crown on the top into the hole. Crown up. Fill the hole up with good rotted manure. This will produce strong straight roots in 2-3 years, some of which may be ready in the first year.
Harvest
Pick leaves young to use fresh, or to dry.
If you have a mature patch of horseradish then the root can be dug up any time for use fresh. Otherwise dig up roots in autumn. Store roots in sand and make sine von leave them in cool dark place for the winter.
Alternatively, wash, grate or slice and dry. Another method is to immerse the whole washed roots in while wine vinegar.
Companion planting
Grow near potatoes to improve their disease resistance. Be careful it does not take over.
Culinary
The reason horseradish is used in sauces, vinegars, and as an accompaniment rather than cooked as a vegetable is that the volatile flavoring oil which is released in grating evaporates rapidly and becomes nothing when cooked. Raw it's a different story. The strongest flavor is from root pulled in the autumn. The spring root is comparatively mild. Fresh root contains calcium, sodium, magnesium and vitamin C, and has antibiotic qualities useful lot preserving food.
It can be used grated in coleslaw, dips, pickled beetroot, cream cheese, mayonnaise and avocado fillings.
The young leaves can be added to salads for a bit of zip.
Make horseradish sauce to accompany roast beef, and smoked oily fish.
Avocado Pear with Horseradish Cream
Fresh horseradish root (approx. 15cm. (6in) long); preserved horseradish in vinegar can be substituted. If it is, leave out the lemon juice.
1 tablespoon butter
3 tablespoons fresh breadcrumbs
1 apple
I dessertspoon yoghurt
I teaspoon lemon juice
Pinch of salt and sugar
1 teaspoon chopped fresh chervil
½ teaspoon each of fresh chopped tarragon and dill
3-4 tablespoons double cream
2 avocado pears {ripe) cut in half with the stones removed
Medicinal
Horseradish is a powerful circulatory stimulant with antibiotic properties. As a diuretic it is effective for lung and urinary infections. It can also be taken internally for gout and rheumatism. Grate into a poultice and apply externally to chilblains, stiff muscles, sciatica, rheumatic joints, to stimulate blood flow. Its sharp pungency frequently has a dramatic effect and has been known to clear the sinuses in one breath.
Other uses
Chop finely into dog food to dispel worms and improve body tone. Make an infusion 600ml (1 pint) water, 25g (1oz) horseradish roots and dilute 4:1. Spray on apple trees to protect against brown rot.The roots and the leaves produce a yellow dye for natural dying.Slice and infuse in milk lot a lotion to improve skin clarity.Peel and grate the horseradish, melt the butter and add the breadcrumbs. Fry until brown, and add grated horseradish. Remove from heat and grate the apple into the mixture. Add yoghurt, lemon juice, salt, sugar and herbs. Put aside to cool. Chill in refrigerator.Just before serving gently fold the cream into the mixture and spoon generously into the avocado pear halves. Serve with green salad and brown toast.