Botanical name: Symphytum officinale
Other common name: knitbone
Description: A non-woody herb with large, hairy leaves growing from a central rosette, pale purple flowers and thick roots. In good conditions the leaf mass grows up to fifty centimetres, with flower stems emerging above the leaves.
- A classic soil builder – the fast growing, mineral-rich leaves can be harvested regularly for use in compost (as an activator) or liquid manure (comfrey tea), or used directly as mulch.
- A medicinal plant, especially useful for healing cuts, bruises and broken bones with a poultice of roots or leaves.
- The leaves are a great feed for livestock, especially poultry.
- With its formidable root system, it makes a useful barrier plant to help protect garden beds from creeping grasses.
- As a companion plant for perennials.
Comfrey grows in cool, temperate and subtropical areas, but dies down in winter in colder areas. It is a tough plant but does best in nutrient-rich moist soil in full sun or semi-shade.
Roots will sprout if broken or cut – it can be hard to remove or transplant without leaving root pieces. Avoid planting it in areas where there is likely to be root disturbance if you don’t want it to spread.
Poultry are likely to destroy the plants if they have direct access – feed leaves to them by hand, or protect it with wire mesh.
Its fast growth enables it to use nutrients rapidly, making it a good plant to put near greywater or septic outflows.
Comfrey contains alkaloids that, in large amounts, can damage the liver, and it has been banned as an internal medicine in Australia despite its long history as a food plant.
Very easy to propagate from root cuttings, and will also grow from seed.