Horseradish (Armoracia rusticana)

Perennial
A. lapathifolia. Gilib. Cochlearia armoracia. Rorippa armoracia.
Common Name Latin Name Plant Family
Horseradish
Armoracia rusticana
Cruciferae

Horseradish tea is effective against brown rot of apples and other fungicidal diseases[18, 201].

The growing plant deters potato eelworm[14].

  • Medicinal Use

    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].

  • Edible Use

    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].

  • Cautionary Notes

    Large quantities of this plant can be poisonous due to its content of volatile oils[76].

Cultivation & Habitat

Seed – this is seldom produced on plants in cultivation[200]. If seed is obtained then it is best sown in situ during the spring[238]. Division is very easy and can be carried out at almost any time of the year, though it is probably best in spring[33]. It s best to use sections of root about 20cm long, which can be planted out into their permanent positions in February or March, though even very small bits of root will grow away[4, 264]. Division should be carried out at least once every three years or the crop will deteriorate[4].
A very easily grown plant, horseradish prefers a good deep moist well-drained soil and a sunny position[16, 27, 33, 200]. Plants require a good soil if they are to produce good roots[4], though once established they are very tolerant of neglect and will continue to produce a crop for many years[264, K]. Plants do not thrive if they are in the shade of trees[264]. Excess nitrogen causes heavy top growth and forking of the roots[200]. Prefers a wet clay soil according to one report[14], whilst another says that it will not grow in wet clay[16]. Tolerates a pH in the range 5.8 to 8.3. Horseradish has long been cultivated for its root which is used as a food flavouring and medicinally, there are some named varieties[4, 17, 61, 183]. If the roots are given some protection they will produce fresh young leaves for the salad bowl all through the winter. Digging up some roots and putting them into a greenhouse for the winter is the easiest method. If the young shoots are blanched they will produce white, tender, sweet leaves[183]. A very invasive plant[33], it is considered to be a pernicious weed in some areas[200]. Even quite small sections of root will regrow if they are left in the soil[4]. The plant has yet to prove invasive on our Cornwall trial grounds, though it has survived and even prospered in a very overgrown site[K]. The forms of this plant grown in gardens are almost sterile and seldom produce good seed[264]. This is a good companion plant for potatoes since it is said to deter potato eelworm[14, 18, 201] and the Colorado beetle[238]. One plant at each corner of the potato patch is quite sufficient[201]. When grown under apple trees it is said to prevent brown rot, powdery mildew and other fungal diseases[201].
Europe. Naturalized in Britain[17].

Become ungovernable, break the chains of the matrix; grow and forage your own food and medicine.

*None of the information on this website qualifies as professional medical advice. Take only what resonates with your heart and use your own personal responsibility for what’s best for you. For more information [brackets] [000], see bibliography.