BOTANICAL NAME: Symphytum officinale
COMMON NAMES: comfrey
FAMILY: Boraginaceae
PLANT DESCRIPTION
Comfrey is a herbaceous perennial herb originating in Europe. It has large, hairy leaves and grows in a rosette to 1 m in height. The mauve flowers are bell-like and borne in clusters. Comfrey rarely flowers in subtropical and tropical areas as there isn't sufficient winter chill to induce flowering. In cold areas it is dormant in winter. It is a hardy plant, with a wide climatic range, from cool temperate to tropical. It provides high yields on fertile, well-watered soil.
USES
Comfrey probably has the widest range of uses in a permaculture system of any plant.
- The leaves are a useful addition to compost or used as mulch, as they contain silica, nitrogen, magnesium, calcium, potassium and iron. Comfrey is lush and fast-growing in the right conditions and can provide abundant supplies of mulch. When planted in the orchard, it can be slashed to provide mulch under fruit trees. Comfrey leaves, measured as dry matter, are about 15 to 30% protein which is as high as most legumes. The leaves readily decompose when soaked in water to make a liquid manure.
- The whole plant is an excellent soil conditioner, the roots penetrate deep into the subsoil and are able to access nutrients beyond the reach of more shallow-rooted plants. This allows the gardener to cycle nutrients leached from the topsoil back to the surface by cutting comfrey leaves and using them as mulch. This deep nutrient mining is particularly useful for the health of soils in heavy rainfall areas. The large, deep roots of comfrey act to break up compacted soils. Plant comfrey downhill from poultry runs or animal pens to trap the nutrients that would otherwise be washed away in heavy rain.
- Weed barrier; one of its more unusual attributes is its ability to stop running grasses in their tracks. When comfrey is planted as a 'weed barrier', it should be in a strip several plants wide.
- Animal forage; the flowers are an excellent bee forage. The leaves are nutritious and readily eaten by poultry but should only be given in small quantities. Comfrey has been used as an animal forage for centuries but modern research suggests that in large quantities it can cause toxicity problems for grazing animals. Comfrey contains pyrrolizidine alkaloids (PA). The amount of PAs is highest in the roots. While the level of PAs in a green plant may not be very high, it can be a cumulative toxin. Pigs, horses, goats and cattle are most commonly poisoned by PAs, while sheep are much more resistant.
PLANTING DETAILS
Recommended Planting Time: Plant in cool areas in spring, in warmer or more tropical areas plant in the wet season. Comfrey can be propagated by root cuttings or crown division. Root cuttings are the most economical, cut pieces of root 3 cm long and lay horizontally in a prepared garden site or a styrofoam box filled with potting mix. The cuttings should be buried 3 cm deep. Keep moist until the first leaves appear.
Spacing: If a row of comfrey is required, space the plants at 50 cm apart.
Growing Details: Try to plant comfrey in the right position the first time as any root disturbance will create new plants. If it has to be removed, simply cover the clump with several layers of wet newspaper and then top with mulch. The comfrey will rot out, leaving a rich, black compost.
