Symphytum officinale - Comfrey

Symphytum officinale, more commonly known as Common Comfrey or Greater Comfrey, is a powerful herbaceous perennial that is quite common in our woodlands, near wet areas or ditches bordering rural paths. Despite its rough appearance as a weed, it displays beautiful terminal inflorescences in spring in the form of small, modestly curved clusters, bearing delicate flowers filled with nectar, in shades of white, cream, pink, or violet. Known since ancient times for its medicinal properties, widely used in agronomy or horticulture, it is also a decorative and easy-to-grow plant. It is ideal for shaded or moist areas, even clayey ones, in a garden that leaves room for nature.

Native to Europe, especially central Europe, western Siberia, central Asia and China, greater comfrey belongs to the Boraginaceae family, just like common borage. Quite variable in nature and easily hybridising with other species, common comfrey invariably has a fleshy and brittle stump with a creeping habit, and develops a powerful root system with a black epidermis protecting a mucilaginous and white flesh. The plant quickly reaches a height of 60 to 80cm (24 to 32in), or even much higher in fertile soil, with a spread of 60cm (24in), and forms large colonies. It is entirely covered with iridescent and prickly hairs at the base of its square stems. From April to June, it bears an abundance of nectar-rich bell-shaped flowers in variable colours, grouped in scorpion-like inflorescences at the tips of the stems. At the end of flowering, the upright stems have a trailing aspect. Its large, rough, semi-evergreen leaves are green and leathery, oblong and lanceolate in shape with prominent veins. In shaded exposure, the leaves reach a length of 20 to 25cm (8 to 10in). This hardy perennial readily self-seeds.

In the garden, greater comfrey is one of the least demanding plants, and one that can adapt to the most unfavourable conditions. It prefers humus-rich soils in partial shade or full shade, but it will also thrive in full sun provided the soil remains cool and moist. All cool spaces are suitable for it. It looks beautiful in woodlands and beside water features, and in an informal bed, accompanied by simple plants such as common lemon balm, common borage, Iris giganticaerulea, garden columbines, or Euphorbia robbiae. It can also be paired with shrubs like rhododendron or hydrangea, as well as perennials like wild garlic or bellflower, for example.

Common comfrey gets its vernacular name of "knitbone" from its ability to consolidate fractures and heal wounds. It is used in many fields such as organic agriculture. It is an excellent fertiliser once transformed into liquid manure. In this form, it is also a good repellent against parasites. It is a fortifying plant for animals due to its richness in vitamin B12. In the garden, its powerful roots allow for the loosening and aerating of even the heaviest soils, thus making it possible to replace comfrey once the work is done with a more delicate and demanding plant.