Comfrey is a perennial herb of the family Boraginaceae with a black tap-root and large, hairy broad leaves that bear small bell-shaped flowers of various colors. Old school comfrey was a voracious self seeder, taking over an area the size of a football field in just a few years. The main species of focus now is russian comfrey, particularly the ‘bocking 14’ cultivar that was developed in the 1950s. Bocking 14 produces a sterile seed that helps stop its spread, the plant will still spread by root but not nearly as quickly.
As far as contemporary herbalists are concerned comfrey is a very controversial herb that, although it offers many therapeutic benefits, has been linked to liver toxicity in a number of studies. Comfrey contains allantoin, which is thought to stimulate cell growth and repair, while simultaneously depressing inflammation. Scientists and physicians agree that comfrey should be used as a topical treatment only and never ingested, the possible benefits of ingestion are outweighed by the damage it can do to the liver.
My issues with comfrey are solely based on removal… In a multi-acre farm setting this would not be an issue, but in the city, removal is something you will have to consider. Even homeownership is no longer permanent… Although comfrey does not spread by seed it will spread like a wildfire when you have to remove it. Comfrey pulls nitrogen from the soil using a deep tap- and an extensive root network, it will sprout from any root left in the ground including the tap-root.
The first time I ever removed a comfrey plant I had planted it in my flower bed, I dug the plant out and filled in the hole thinking nothing of it, a few weeks later I noticed 10 new plants coming up. I dug each one of the new plants out and composted them, 2 weeks later I had several hundred of them coming up all over the place, I ended up removing and replacing 3 square yards of topsoil to remedy the situation.
Now that I know what goes into removing the plant, I don’t plant it anywhere near my house or flower beds, but I do grow it… I just respect it now. Comfrey really is a valuable source of fertility for the organic gardener acting as a dynamic accumulator, mining a host of nutrients from the soil. These nutrients can easily be incorporated through teas, compost activator, tillage and mulch or side dressings, the only real differences you will find is the amount of time needed for the nutrients to become chemically available to the plants.
I find as long as comfrey is planted in an out-of-the-way area you will have no problems, find an abandoned house and fill the yard with comfrey if you want. Comfrey should be planted with an awareness of removal, way to many gardeners have tons of experience planting things, but they have never had to remove them. Permaculture is not a “set in stone” list of plants that you can put under trees, even though I don’t like comfrey in an urban setting, a lot of people do. I do not like the fact that every piece of permaculture literature I read requires comfrey to be interplanted with everything, I prefer to plant it off site, harvest it, and then move it in when needed. Just something to think about…
peace – chriscondello
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