Practical Urban Permaculture – Comfrey Cautions

Comfrey has been recognized as a versatile plant for the organic gardener for a long time, it is used in medicine and as a fertilizer.

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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7 thoughts on “Practical Urban Permaculture – Comfrey Cautions

  1. sunnyromy says:

    Reblogged this on SunnyRomy.


  2. dee fairchild says:

    hi, if you plant comfrey, like dead or stinging nettle in compost heaps made in those white builders bags, you will be able to harvest a ton of leaves, but the compost is loose enough that the roots can be shaken free each year. peeps also need to be aware that comfrey can upset sensitive skin, wear gloves and use aloe vera if necessary. i would find/scrounge the bags, make a hot compost heap with horse manure (you could use rabbit bedding etc, but NEVER chicken manure) and old leaves at the bottom and lots of brown paper, newspaper and cardboard as a middle layer. then plant waste and brown/newspaper and soil again. i would plant a comfrey, a nettle and then a squash plant, with a 2L plant pot upended and marking the squash root. At the end of the season, after harvesting and first frost, turn the heap, plant the comfrey root bases in a bucket and cover with straw. spread the rest on your beds as a mulch now or in spring. repeat every year and the comfrey and nettle plants can’t become invasive. the extra heat helps the squash, the complete cover speeds the breakdown of the manure, and as i would put the bag on top of old carpet as i cleared my derelict allotment, i could crop while waiting to see what nightmares lay below (think 17 car batteries, 55 sacks of asbestos, 55 buckets of glass…) win, win, win… 😉


  3. Dia says:

    Great information. I have one Russian comfrey planted years ago for use in composting and for making the malodorous “tea” that my plants love and my neighbors graciously tolerate. (Mostly in compost though for the neighbors’ sake.) It’s an old plant that I love…and we have no thought of moving until we die…but I had no idea it would be so difficult to remove and would have thought twice had I realized. A truly great heads-up for the future. Thanks.


  4. Hi Chris

    Please come back and vote too!


  5. Hi Chris one of my projects is a railway line siding which is about 2 km of very inhospitable territory. It gets quite wind battered and sunbaked and having been sprayed with herbisides for the last 5o years there has not been much organic matter in the soil. Soil being a liberal terms for a pile of rock with a little very sand loose composite here and there. The old section where I have worked and where I can get water too is really coming on well. I just wondered if you thought comfrey might work in the more desolate places. Would the harsh conditions keep it in check. It really would be good to get something to add some nutrition to the area. On the other hand I would hate it to overrun everything else. Any suggestions.


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