Comfrey
Symphytum officinale L.
Botanical family: Boraginaceae
A large perennial of the Boraginaceae family (Symphytum officinale), with powerful roots and potassium-rich leaves. Cut several times a year, these make a rich mulch and a fertilising liquid manure prized in permaculture. Nectar-bearing, it feeds mainly bumblebees; the 'Bocking 14' variety, sterile, does not self-seed.
Partial shade
Deep, rich
Regular: a plant of damp meadows, which prefers moist, rich soil
Very hardy
Overwinters in your zone
Role in permaculture
A mainstay of fruit-tree guilds: its potassium-rich leaves are cut several times a season and dropped at the base of trees as a living mulch (chop-and-drop) or steeped into a potassium-rich liquid feed, traditionally used to support flowering and fruiting. Ringed around an apple tree, it covers the ground, checks competing grass and draws bumblebees to its nectar-rich bells. The sterile 'Bocking 14' cultivar does not self-seed, which keeps it easy to contain. It is one of the most widely used fertilising-biomass plants in permaculture.
Good companions
Traditional companion planting (benefit not demonstrated)
Insects attracted or useful
Seasons & availability
A perennial increased by dividing the crown or by sowing; it flowers from May to July, and the leaves are cut three to five times a year, from spring to the end of summer.
Available: April, May, June, July, August, September.
Guidance for the oceanic / temperate climate; it may vary with your region, altitude, exposure and growing method.
Sources
- La Ferme de Sainte Marthe, « Réussir la culture de la consoude » (fermedesaintemarthe.com/en/blogs/comment-reussir-la-culture-de/reussir-la-culture-de-la-consoude)
- Plants For A Future, « Symphytum officinale » (pfaf.org/user/Plant.aspx?LatinName=Symphytum+officinale)
- Tela Botanica, « Symphytum officinale L. » (tela-botanica.org/bdtfx-nn-75402-description)
Nutritional & medicinal properties
For educational purposes. Not a substitute for medical advice. Effects depend on the form, the dose and personal context.
Precautions & contraindications
Internal use formally not advised (ESCOP, EMA): its pyrrolizidine alkaloids are hepatotoxic, with a cumulative toxic effect on the liver. External use possible ONLY on intact skin (never on an open wound, transcutaneous absorption of the PAs is documented). Limit to 4-6 weeks per year cumulatively. Not advised in pregnancy, breastfeeding, and in children even externally. When harvesting, do not confuse the rosette (before flowering) with that of foxglove (Digitalis purpurea), toxic or even LETHAL (heart-rhythm disturbances): the comfrey leaf is rough, bristling with hairs, and decurrent (it runs down the stem), the foxglove leaf soft and downy; if in any doubt, wait for flowering. Sources: ANSES, “Cet été, à quelles plantes faire attention pour éviter les intoxications?” (2022); Tela Botanica, “Symphytum officinale L.” and “Digitalis purpurea L.” (Coste's flora); Plants For A Future, “Symphytum officinale”.
In the kitchen & the apothecary
Where to find comfrey in preparations: recipes and traditional herbal teas.
Recipes
Family behaviour: Boraginaceae
In general, Boraginaceae bear very nectar-rich flowers on hairy foliage (borage, comfrey); their cut leaves make a mulch and a liquid feed rich in potassium. Excellent neighbours and refuges for pollinators.
Understanding families means learning one rule per family rather than every pairing one by one. Learn more →
Species & varieties
The best-known species and varieties in France.
Species
Common varieties
Voices of peoples
Paraphrases attributed to their documented sources. Never an invented quote.
English and Scottish rural tradition · British Isles, Middle Ages to 19th century
In the English countryside, comfrey bears the name 'knit-bone', 'that which knits the bones back together'. Its botanical name Symphytum comes from the Greek sumphuo, 'to grow together', 'to knit'. The old herbalists credited it with mending fractures as well as tears in leather, cloth, and bindings. According to them, some plants spoke to what was broken.
Maud Grieve, A Modern Herbal, Jonathan Cape, 1931 (entrée Comfrey).
Keep in mind
The real, measured value of comfrey is that of a potassium-rich fertilising biomass (mulch), according to Tyler and Zarro (Cornell Small Farms, 2022). The idea of a 'dynamic accumulator' that would pump minerals up from deep layers is poorly supported: its leaf content depends on the soil it grows in.
A note on rigour: many companion pairings are gardening folklore; this note sums up what the sources say, where there are any.
Before you forage
This plant is often gathered from the wild. Only pick what is abundant, never a protected species, and never uproot a whole plant (roots) without the landowner's permission. Rules vary by country and region, check locally.
Key takeaways
- • Prefers partial shade exposure.
- • Ideal soil: deep, rich.
- • Classic companion: Apple tree.