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A wide variety of plants growing in the Medieval Herb Garden on a sunny day

Medieval herb garden blog 74: Comfrey

Wednesday, June 10, 2026

Week 74 volunteer update

Due to the garden being sopping wet, little work could be done this morning. Carole and Kim weeded in front of the lavender. They then planted some more nasturtiums on the drystone wall.

$Green nasturtiums planted on the drystone wall at Pontefract Castle.$

New nasturtiums planted on the drystone wall at Pontefract Castle.

Carole spoke to several visitors. The first was a development chef from a restaurant in Aberdare, South Wales. They were particularly interested in our Russian tarragon. After speaking to a couple from Salisbury, Kim and Carole talked to a visitor from Seattle, Washington. The visitor thought his family was related to Ilbert de Lacy, the first owner of Pontefract Castle in the eleventh century.

Plant of the week: Comfrey (Symphytum officinale)

'Symphytum' comes from the Greek word 'symphyton'. It combines 'syn' (together) and 'phyton' (plant) or 'symphyo' (to grow together).

'Officinale' is from the Latin 'officina'. It means a workshop, storeroom, or pharmacy, where herbs were traditionally kept.

The word 'comfrey' comes from the Latin 'confervere' (to boil together). This is via the old French 'cumfirie', and then the middle English 'comferi'.

Its common names are knitbone, knitback, consound, blackworm, bruisewort, slippery root, boneset, gum plant, consolida, and ass ear.

Being native to Europe and Asia, comfrey is a deep rooted, bushy, deciduous, perennial plant. It will grow in any moist to well-drained, soil type of any pH, and prefers full sun to partial shade.

Comfrey grows to a height and spread of 4 ft (1.2 m) to 5 ft (1.5 m). It will regrow if chopped back after the first flush of flowers are spent.

It has hairy stems and coarse, hairy, dark-green leaves. Its leaves grow up to 1 ft (30 cm) in length; these decrease in size the higher up the stem they grow. The stems are multi-branched, terminating with one-sided clusters of drooping flowers.

The flowers arrive in late Spring and early Summer. They are hanging clusters of pairs of tubular, scorpioid, purple flowers. The flowers can be up to 1 inch (2.5 cm) in length and have winged stalks.

Comfrey produces small 5 to 6 mm pods containing four glossy, egg-shaped seeds. The seeds mature to a shiny, brownish-black colour.

Comfrey has a large, fleshy taproot that can grow up to 6 feet (1.8 m) deep. They are white, juicy, and covered with a distinctive dark brown to black bark.

New plants will grow from any remaining piece of root. This makes the plant extremely difficult to eradicate.

Comfrey is practically scentless. However, when crushed, the leaves give a faint, earthy, green, or cucumber-like smell.

Lots of tiny pale purple flower clusters growing on green leaves

Comfrey in flower in the Medieval Herb Garden

Culinary uses of comfrey

Comfrey used to be treated as a leaf vegetable. Young leaves were boiled or sautéed like spinach or were coated in batter and deep-fried.

However, regular consumption can lead to liver damage and cancer.

Use of comfrey as a dye plant

Comfrey produces subtle yellows, browns, and olives.

Folklore and other facts about comfrey

In Europe, comfrey has been used for tanning leather. In Angora a glue is made from it.

Comfrey contains high levels of nitrogen, phosphorus and potassium. This makes it good for adding to compost heaps. It can also be made into liquid fertiliser. However, as it ferments, it produces a "highly putrid, foul, and stagnant stench" often compared to manure.

Comfrey attracts pollinators. In particular hoverflies and bumblebees, as well as lacewings, parasitoid wasps and spiders.

Medieval medicinal uses of comfrey*

Pliny the Elder's (23? - 79 AD) 'Naturalis Historia' cites comfrey for the treatment of bruises and sprains in book 26, chapter 137. Chapter 148 also claims that comfrey ensured the rapid healing of wounds.

Comfrey was also used internally, treating lung problems, stomach ulcers and digestive issues.

Nicholas Culpeper (1616 - 1654) recommended comfrey for: “Spitting, pissing Blood, Inward Wounds & Bruises, Phtisick, Bloody Flux, Terms stops, Whites, Nervs cut, Muscles cut, sharp Humors, Wounds, Ruptures, broken Bones, Knotted Breasts, Hemorrhoids, Inflamation, Gout, Pained Joynts, and Gangreans”.

Comfrey was also thought to be “special good for ruptures and broken bones; yea, it is said to be so powerful to consolidate and knit together, that if they be boiled with dissevered pieces of flesh in a pot, it will join them together again.”

*As always, this isn't to be considered medical advice today. Please don't use any plants mentioned in these blogs as medicine without advice from a doctor.

Medieval herb garden blogs

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