Comfrey

I have lots of favorite plants, but comfrey has to be pretty close to the top of my list. For all around versatility, usefulness (culinary, medicinal, agricultural, horticultural), ease of propagation and growth very few plants can match it). Comfrey should be in every food garden, it has so many uses you will no doubt find at least one you can’t do without (it is also quite attractive). I can’t think of a reason to not grow it (unless you have some kind of phobia about it I suppose).

For centuries Comfrey was considered an important edible plant and was widely eaten by country people, but in recent years this use has become controversial. It is now known that the leaves and (especially the roots) contain toxic pyrrolidizine alkaloids, which have led to it being classified as a poisonous plant. Exactly how much of these alkaloids are found in comfrey, of what kind, and exactly how dangerous they are, is the subject of some debate, with two opposing camps. On the one hand you have the scientists with their scientific methods, who decided that the plant contains toxins and must therefore be dangerous. On the other hand you have the traditionalists who say the plant has such a long history of use as food for domestic livestock (and humans) with no apparent ill effects (in fact only apparently beneficial effects) that it should be considered fairly safe.

I would never recommend that anyone eat comfrey because I can’t say for absolute certainty that it’s safe, but I throw a few leaves into my green blender drinks (see separate post) without any qualms. The young leaves have also been eaten as a potherb (they are too rough to be good raw) for centuries by country people. They were once popular fried in batter.

Comfrey also has a long history of medicinal use, for healing burns, wounds, ulcers, insect bites, sprains, broken bones, torn ligaments and bruises. The leaves or roots can be used as a poultice (put the leaves in a blender with a small quantity of water and some flour to thicken), or mixed with oil and beeswax to make a wonderful salve.

Comfrey is one of the world’s most efficient producers of plant protein (yielding up to six times as much per acre as Soybean) and is also rich in vitamins A, C and (maybe) vitamin B12 (one of the few vegetable sources), as well as calcium, phosphorus and potassium. It has been widely used as feed for livestock in the past. Horses, goats, pigs, sheep and poultry will eat it fresh, rabbits and cattle will eat it when wilted (which eliminates the rough hairs and reduces its water content). It is particularly well suited to feeding chickens and can be used to supplement (or even to replace) commercial feed.

In the garden Comfrey can be used as a groundcover, ornamental foliage plant, or to fill in any spare ground (to cover the soil, prevent weed growth and to make it productive). If you have a suitable site you could have a large bed of comfrey for use as fertilizer, perhaps irrigated with gray water and fertilized with Humanure.

Comfrey is usually grown from root cuttings and few plants are as easy to propagate vegetatively. All you need is a single piece of root and within a few years you can have as many plants as you could possibly use. Plant a single root and it will grow into a substantial plant in one summer, which can then be broken up into a whole series of root cuttings and replanted. These will all grow into new plants and can in turn be broken up. The simplest way to propagate established comfrey is with a shovel, simply cut off the top 6 inches of root and replant it (maybe break it up into several pieces). The broken off roots that remain in the ground will all grow into new plants too.

Comfrey is one of the most important non-nitrogen-fixing fertility plants and has few equals as a fertilizer and soil builder. Its vigorous root system breaks up compacted soil and mines the subsoil for nutrients. The nitrogen and potassium content of the leaves makes them an excellent green manure and compost material (they can even provide the nitrogen component of compost piles). For maximum production the leaves should be cut regularly (4-5 times in a summer). They will grow in part shade, but do much better in full sun.

Comfrey leaves can also be used to make a liquid foliar fertilizer. Just fill a bucket with as many leaves as it will hold, top it up with water, cover and leave to ferment for 2 ‑ 3 days. Then strain out the remaining fibers, dilute with an equal amount of water and apply with a watering can. The resulting anaerobic fermentation makes this a smelly process however. If this is too smelly you could try making aerated compost tea by bubbling air through it.