Comfrey herb

Native to Europe and Asia, it was introduced into America in the 17th century, where it has naturalized. Traditionally known as Saracen's root, common comfrey is believed to have been brought to England by the Crusaders who had discovered its value as a healing agent -mucilaginous secretions strong enough to act as a bone-setting plaster and which gave it the nickname Knitbone. The Crusaders passed it to monks for cultivation in their monastic herb gardens, dedicated to the care of the sick. Elizabethan physicians and herbalists were never without it. A recipe from that time is for an ointment made from comfrey root boiled in sugar and liquorice, and mixed with coltsfoot, mallow and poppy seed. People also made comfrey tea for colds and bronchitis. But times have panacea for all ills, under suspicion as a line with its common 'Bruisewort', research in has shown that comfrey breaks down the red blood cells. At the same time, the Japanese are investigating how to harness its beneficial qualities: there is a research programme into the high protein and vitamin B content of the herb.

Species

Symphytum 'Bocking 4'

Hardy perennial. Ht 1m (3ft), spread indefinite. Flowers near to violet in color, in spring and early summer. Thick, solid stems. Large green lance-shaped leaves. Not a particularly attractive plant but it contains almost 35 per cent total protein, the same percentage as in Soya beans. Comfrey is an important animal feed in some parts of the world especially Africa.

Symphytum 'Bocking 14'

Hardy perennial. Ht 1m (3ft), spread indefinite.  Mauve flowers in spring and early summer. Thin stems. Green oval leaves, tapering to a point. This variety has the highest potash content, which makes it the best for producing liquid manure.

Symphytum 'Hidcote Blue'

Comfrey hidcote blue

Hardy perennial. Ht 50cm (20in) spread 60cm (2ft). Pale blue flowers in spring and early summer. Green lance-shaped leaves. Very attractive in a large border.

Symphytum ibericum (grandiflorium)

Dwarf comfrey

Hardy perennial. Ht 25cm (10in), spread 1m (3ft). Yellow/white flowers in spring. Green lance-shaped leaves. An excellent ground cover plant, having foliage  throughout most winters. This comfrey contains little potassium and no allantoin, the crucial medicinal substance.

Symphytum officinale

Comfrey (Wild or Common)

Hardy perennial. Ht and spread lm (3ft). White/ purple/pink flowers in summer. This is the best medicinal comfrey and can also be employed as a liquid feed, although the potassium content is only 3.09 per cent compared to Bocking 14s 7.09 per cent. It makes a first class composting plant, as it helps the rapid breakdown of other compost materials.

Symphytum x uplandicum

Russian Comfrey

Hardy perennial. Ht lm (3ft), spread indefinite. Pink/purple flowers in Pink/purple flowers in summer. Green lance-shaped leaves. This is a hybrid which occurred naturally in Upland, Sweden. It is a cross between S. officinale, the herbalist's comfrey, and S. asperum, the blue-flowered, prickly comfrey from Russia. A very attractive form of this variety is S. x uplandicutn 'Variegatum', which has cream and green leaves.

Cultivation

Propagation

Seed

Not nearly as reliable as root cutting or division. Sow in spring or autumn in either seed or plug trays. Germination slow and erratic.

Root cuttings

Dig up a piece of root, cut into 2cm   (1in) sections, and put these small sections into a prepared plug or seed tray.

Division

Use either the double spade method or simply dig up a chunk in the spring and replant it elsewhere.

Pests and Diseases

Sometimes suffers from rust and powdery mildew in late autumn. In both cases cut the plant down and burn the contaminated leaves.

Maintenance

Spring: Sow seeds. Divide plants. Take root cuttings.

Summer: Cut back leaves for composting, or to use as mulch around other herbs in the growing season.

Autumn: Sow seeds.

Winter: None needed

Garden cultivation

Fully hardy in the garden, all the comfreys prefer sun or semi-shade and a moist soil, but will tolerate most conditions. The large tap root can cause problems if you want to move the plant. When doing this make sure you dig up the entire root because any left behind will reappear later.

Harvest

Cut leaves with shears from early summer lo autumn to provide foliage for making liquid feed. Each plant is able to give lour cuts a year if well fed. Cut leaves for diving before flowering. Dig up roots in autumn for drying.

Container growing

Comfrey is not suitable for growing indoors, but it can be grown on a patio as long as the container is large enough. Situate in partial shade and give plenty of water in warm weather.

Culinary

Fresh leaves and shoots were eaten as a vegetable or salad and there is no reason to suppose that it is dangerous to do so now, although it may be best to err on the side of caution until suspicions are resolved.

Liquid manure

A quickly available source of potassium for the organic gardener. One method of extracting it is to put 6kg (141b) of freshly cut comfrey into a 90 litre (20 gallons) tapped, fiberglass water butt. Do not use metal as rust will add toxic quantities of iron oxide to the liquid manure. Fill up the butt with rain or tap water and cover with a lid to exclude the light. In about 4 weeks a clear liquid can be drawn off from the tap at the bottom. Ideal feed for tomatoes, onions, gooseberries, beans and all potash hungry crops. It can be used as a foliar feed. The disadvantage of this method is that the liquid slinks, because comfrey foliage is about 3.4 per cent protein, and when proteins break down they smell. An alternative is to bore a hole into the side (just above the bottom) of a plastic dustbin. Stand the container on bricks, so that it is far enough off the ground to allow a dish to be placed under the hole. Pack it solid with cut comfrey, and place something (a heavy lump of concrete) on top to weigh down the leaves. Cover with lid, and in about 3 weeks a black liquid will drip from the hole into dish. This concentrate can be stored in a screw top bottle if you do not want to use it immediately. Dilute it 1 part to 40 parts water, and if you plan to use is as a foliar feed, strain it first.

Medicinal

Comfrey has received much attention in recent years, both as a valuable healing herb, a source of Vitamin Bl2 and self-proliferate allantoin, and as a potential source of protein. Comfrey is also useful as a poultice for varicose ulcers and a compress for varicose veins, and it alleviates and heals minor burns.

Other uses

Boil fresh leaves for golden fabric dye. Comfrey is a good feed for racehorses and helps cure laminitis. For curing septic sores on animals, make a poultice between clean pieces of cotton and tie to the affected places.