Comfrey, treasure of our gardens, enemy of the pharmaceutical laboratories

This vivacious and vigorous plant draws deep in the soil large amounts of mineral elements (including potash) that it then restores to other plants. Its rich allantois, which promotes the multiplication of cells, stimulates the microbial life of the soil, facilitates the emergence of seedlings and promotes leaf growth.

It is used for so many things, is so undemanding and the good idea to push everywhere! Originally from Europe, comfrey or Symphytum officinale grows naturally on the edge of the forest, in wet areas (moat, creek edge, wet meadow …).

The ancient Greeks thought that this plant could heal all the injured organs. This plant has been used since the dawn of time, since it has been found in the food of cavemen. It has unfortunately fallen into disuse, but has experienced a revival in the Anglo-Saxon countries since the 19th century. It has long been used to feed animals: horses, cows, pigs, hens (which lay more and better).

The plant can be eaten fresh as well as dried, in feed (it is rich in protein, up to 35% of the dry matter). The Romans cultivated it where they went: they “retap” with comfrey old carnes they bought at low prices, and resold them much more expensive a few weeks later!

This plant will look far for its nutrients: its root, once installed, plunges to 1.5 m and even two meters deep! No herbaceous plant goes so far. Once installed (at the end of 2 or 3 years) it does not fear any more, but before, it is necessary to take care that it has a sufficient watering, to bring him nitrogen, for example in the form of manure of nettles, and weeding around it. She likes deep lands, because of the development of her roots.

It makes an excellent fertilizer, rich in potash, so very complementary to the nettle, which is rich in nitrogen. When planting, one can take some fresh leaves of nettle, one or two of comfrey, cut them into pieces, and put them directly at the bottom of the planting hole. Guaranteed return of the plant!

Is she the enemy to shoot?


In recent years this plant is controversial across the Atlantic. It contains alkaloids, mainly concentrated in the root, seeds and young leaves. Several studies have been conducted but the results are contradictory.

Advocates of the comfrey denounce the studies conducted by the pharmaceutical industry, according to which this plant could cause liver disease, called veno-occlusive liver disease or Budd-Chiari syndrome.

This disease causes narrowing of the blood vessels of the liver resulting in poor liver function. As a result of these studies, carried out in the 1980s, Canada and the United States have taken measures to prohibit or restrict the use of this plant, provoking the anger and indignation of many citizens, herbalists, specialists, who cry scandal.

So what is it?

What remains certain is that this plant has been used by men for more than two thousand years, both for its therapeutic and nutritional properties. For internal use (food and care), it is better to consume only mature leaves (avoid roots and young shoots), and to be confined to the Symphytum officinalis, the wild comfrey, also called Comfrey, Comfrey, or cut grass.

Avoid “Comfrey of Russia” or “Bocking 14” cultivars, species sold in specialized stores, and prefer wild and local comfrey, found at forest edges, near streams and all places wet.

For the garden

Purin de consoude:

Comfrey manure is actually an extract obtained by maceration in water and fermentation. The active substances are concentrated there. To prevent the liquid from spoiling, you will have to filter it. Like all manures, that of Comfrey is kept in a hermetically sealed bottle or plastic container for several months in the dark and at about 12 ° C.

A kilo of fresh plant for 10 liters of water (preferably rain or spring water).

Coarsely chop the plants. Fermentation takes 15 days at 18 ° C. It can be longer in the spring, or faster in the summer. It feels less bad than the nettle manure! To use diluted from 5 to 30%, on the ground, not on the leaves. Comfrey is used especially for plants giving fruits or tubers. You can add to horsetail maceration, wormwood, tansy, thyme, etc. to add insecticidal and disinfectant properties. Let’s not forget the nettle, of course, with which it forms a very complete fertilizer.

How to use it :

• Place a few handfuls of fresh leaves at the foot of tomatoes, squash and fruit trees. You can also drag it into the compost to activate it.

• Place the stems and leaves, dried for 48 hours, directly in the planting furrow of the potatoes or incorporate them in the fall, when tillage.

Comfrey is also used to make dyeing: with leaves and stems, with alum as a mordant, it has yellow, with tin of lemon yellow, with chrome a light orange.

The medicinal properties of comfrey come from the allantoin it contains, which is a very powerful cell growth activator. For this purpose, the root is preferred, which is much richer. As we saw earlier, do not abuse in internal use, but there is no restriction for external use, alkaloids are not absorbed by the skin.

Comfrey was very much used by nannies, who often suffered from cracks in their breasts: they dug a hole in a comfrey root, and put on their breast.

Comfrey leaves, cooked in poultices, have long been used to cure animal eczema.

In medicinal use

This plant has been used for more than 2,000 years in traditional medicine. For example, Dioscoride, a Greek doctor, advised her to treat hemorrhoids as well as pulmonary or digestive inflammations. It contains rosmarinic acid, a recognized anti-inflammatory, as well as mucilage with emollient properties and allantoin, a healing substance.

These active substances are generally credited with the therapeutic properties of comfrey administered internally, but these uses have been abandoned because comfrey may contain potentially toxic pyrrolizidines for the liver. Nowadays, we generally limit its use to external applications.

General Properties, comfrey is:

Healing, vulnerable (heals wounds), astringent, emollient, bicic (calms cough), refreshing (calms thirst, decreases body temperature), soothing (calms inflammation), soothing, analgesic, antihemorrhagic.

The harvest time of the root is at the end of winter, the leaves throughout the growing season, for easier drying before flowering. As for nettle, it can be dried overhead to use comfrey throughout the year. Maria Treben Ointment: Cut in small pieces 4 to 6 fresh and washed roots. Fry them briefly in 250 g lard, leave overnight. Warm the next day, filter. Put in small containers and store in the refrigerator. Treats wounds in humans and animals.

What is most active is the fresh root pulp, as a poultice on even infected wounds, burns, fractures, ulcers, sprains, & c.

Decoction for compresses: 200 g root in 1 liter of water, boil ¼ hour. Because of its regenerating power, the comfrey root is also used for cosmetic treatments.


  • Chop the fresh leaves, then pour on them boiling water. Or pour comfrey leaf flour into boiling water to get a thick paste. This soft and green porridge is wrapped in gauze (double layer) or linted to apply it by holding it with a bandage on the part to be treated. This process allows the release of allantoin, while sterilization is ensured. The poultices must be renewed every three hours as an indication. Apply the hottest poultice.
  • To avoid having to put gauze, prepare a compact paste by mixing half and half of the starch or a starchy substance and comfrey leaf flour. Mix the starch in cold water to obtain a thick paste. Pour boiling water to obtain a slightly liquid paste. Mix the comfrey flour immediately to dry the mixture to a consistency that adheres to the skin, but can be removed without leaving a trace. Applied without gauze, directly on the skin, it keeps the heat for quite a long time being quite light.
  • 100 g of roots peeled in 1/4 l of decoction water 10-15 min. Apply in the same way a minimum of 15 minutes every three hours. The root contains twice as much allantoin and Bocking 14 is the richest.


Apart from drying, you can also freeze the comfrey and make some preserves, as for the nettle. In England, comfrey is found in natural products stores, in many forms. Comfrey can be cooked like spinach. You can also use large leaves to make spring rolls, meat or cereals.

Quote from Hildegarde of Bingen (1) : “If one has a broken or injured limb, or covered with ulcers, eat comfrey. But comfrey taken for no reason sends the rot inside: it is like throwing stones into a large ditch to prevent the water from leaving, and then the mud is at the bottom. “

(1) Hildegarde de Bingen (1098-1179), a visionary, poet and musician of the first rank, is considered the first true modern herbalist.

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