Horseradish, Red Cole

Armoracia rusticana

Physical Characteristics

Armoracia rusticana is a PERENNIAL growing to 0.7 m (2ft 4in) by 0.8 m (2ft 7in) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 5 and is not frost tender. It is in flower from May to June. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees, flies, beetles. The plant is self-fertile. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very alkaline soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Distribution

Europe. Naturalized in Britain[17].

Habitats

Woodland Garden Sunny Edge; Dappled Shade;

Edible Uses

Edible Parts: Leaves Root Seed Edible Uses: Condiment Young root - raw or cooked. The grated root is used to make the condiment 'Horseradish sauce'[2, 9, 13, 14, 27, 33, 34, 52], this has a hot mustard-like flavour[100]. The sauce is best used uncooked or gently warmed, heating it will destroy the volatile oils that are responsible for its pungency[238]. It is said that in Germany the roots are sliced and cooked like parsnips[183] - rather them than me![K]. The root is a rich source of sulphur[201]. Fresh roots contain the glycoside sinigrin - this is decomposed in the presence of water by the enzyme myrosin, producing mustard oil which gives the root its hot flavour[268]. The fleshy roots can be up to 60cm long and 5cm thick[268]. The plant is fully hardy and can be left in the ground all winter to be harvested as required[4]. Alternatively, the roots can be harvested in early winter and stored for later use, they will retain their juicy state for some time if stored in dry sand[4]. Young leaves - raw or cooked[2, 9, 14, 177]. A very strong flavour, though nice when added in small quantities to the salad bowl[183, K]. A pleasant mild flavour according to another report[238]. Seeds - sprouted and eaten in salads[183].

Medicinal Uses

Antibacterial Antirheumatic Antiseptic Aperient Digestive Diuretic Expectorant Rubefacient Stimulant Urinary Horseradish is a very pungent stimulant herb that controls bacterial infections and can be used both internally and externally[238]. The plant is a powerful stimulant, whether used internally as a spur for the digestive system or externally as a rubefacient[4]. It should not be used internally by people with stomach ulcers or thyroid problems[238]. The roots are antiseptic, aperient, digestive, diuretic, expectorant, rubefacient and stimulant[4, 13, 14, 165, 171, 222]. They should be used in their fresh state[4]. An infusion is used in the treatment of colds, fevers and flu and is of value in the treatment of respiratory and urinary tract infections[254]. A sandwich of the freshly grated root is a traditional remedy for hay fever[254]. A tea made from the root is weakly diuretic, antiseptic and expectorant[222]. The plant is antibiotic against gram-negative and gram-positive bacteria and also pathogenic fungi[222, 240]. It is experimentally antitumor[222]. Externally, a poultice made from the roots is used to treat pleurisy, arthritis and infected wounds[238]. It will also relieve the pain of chilblains[244]. Some caution should be employed, however, because it can cause blistering[254]. The German Commission E Monographs, a therapeutic guide to herbal medicine, approve Armoracia rusticana for internal & external use in catarrhs of the respiratory tract, internally as supportive therapy for urinary tract infections, externally for the hyperaemic treatment of minor muscles aches (see [302] for critics of commission E).

Known Hazards

Large quantities of this plant can be poisonous due to its content of volatile oils[76]. Traditional texts suggested possible thyroid function depression. Contraindicated with chronic nephritis, hepatitis, gastro-oesophageal reflux or hyperacidity conditions, and inflammatory bowel conditions. Avoid during pregnancy and lactation (moderate amounts with food ok)[301].