Comfrey: super-plant or overrated weed? Have you ever wondered why useful plants are usually delicate creatures, yet weeds just thrive, without any care at all, and pondered wouldn’t it be wonderful if there was such a thing as a useful weed? Comfrey is it. A perennial herb, a member of the borage family, its deep tap roots mine the soil of nutrients, filling its leaves with minerals such as the holy trinity of plant food, nitrogen, and phosphorous and potassium, along with calcium and iron. It remains only to harvest it and make a comfrey “tea” (concentrate) to use as a plant food, use it as a mulch and even feed it to animals. Comfrey leaves contain more Nitrogen and Potassium/Potash (K) than farmyard manure or garden compost and more Phosphorus than farmyard manure. They have a low fibre content, so they readily decompose, producing comfrey tea and a relatively low carbon to nitrogen ratio so that they don’t rob the soil of nitrogen as they decompose (when laid on the surface or dug in).
If I plant it, will it spread like a weed? That depends on what variety of comfrey you have. Common comfrey Symphytum officinale, seeds freely and therefore may well become a problem. Russian comfrey (Symphytum x uplandicum) on the other hand, produces very little viable seed, so conveniently stays where you put it. But it will always stay where you put it, as you’ll never dig it out without breaking off a little bit of root, which will re-grow, so choose the position of your comfrey patch with care. The Bocking 14 cultivar of Russian Comfrey was developed during the 1950s by Lawrence D Hills, founder of the Henry Doubleday Research Association (now called Garden Organic) and is even richer in the useful minerals. The Bocking 4 cultivar was developed to be more suitable as animal fodder but I can’t source any in the UK or France and have only found Richters in Canada selling it.
How do I grow comfrey? Without seed, we propagate it from root cuttings. Simply plant your root cuttings just below the surface, water them in and wait (you can mulch them with cardboard, as we’ve done here, see photo). One extra tip, use some anti-slug and snail strategies until the plants get up and going, as these gastropods really like comfrey (another of its uses to place cut leaves around plants as a slug barrier, as the slugs will go for the comfrey, in preference). If you’re starting off, I suggest that you buy no more than six plants. You’d be surprised how much leaf material you’ll be able to crop once the plants are established (leave them a year before you start cropping).
They might mine all these nutrients for you but they also appreciate being fed and are greedy for nitrogen when growing; they can cope with fresh (i.e., uncomposted) chicken manure, so we tend to clean our chicken house onto our nearby comfrey patch.
You’ll also then be able to propagate further plants by lifting one and divide the roots into offsets and cuttings (see photo: offsets at the top, cuttings below) and then plant these as you did with your original cuttings, and don’t forget to put one bit back in the hole where you lifted the original plant from.
When and how to cut comfrey? Use ordinary hedge trimming shears and chop it off 5cm (2 inches) above the ground.
Think about wearing gloves as the bristles can irritate your skin. Cut in spring, when the plants are around 60 cm (2 feet) high and before flowering stems develop. Once the plant is well established—I’d give the plant a year to settle in before you start harvesting leaves—cut every time the plant reaches 60 cm (2 feet) high and before flowering stems develop and you should get several cuts a season. At the end of summer, stop cutting, letting the plant grow on and build up its strength to see winter through.How do I make comfrey tea?
Making comfrey tea – liquid concentrate. I think that the video explains all. This photo shows the plastic dustbin full of leaves which reduces to the goo in the video, don’t add water. Dilute to use, 20 water to 1 comfrey juice (by volume) when it’s thick and black or 10:1 if it’s thinner and brown in colour.
Do animals like comfrey? Whether fair or not, the spread of wild comfrey along roadside hedgerows is often attributed to gypsies that fed comfrey leaves to their horses as a tonic. It’s said that Russian comfrey was introduced into Britain specifically as a fodder plant. We’ve got an established comfrey patch. The chickens peck at it en passant, a sort of “Drive-Thru” eatery, and Bunny Lapine scoffs it, so I recently thought I try out our pigs and goats on it. Fellow NotDabbling writer Monica, told me that she planted comfrey some years ago, “but the sheep ate it all before it could get going and I lost it.” So it’s thumbs up from sheep. However, our pigs, who are free range, and so have a wide variety of stuff to snack on, didn’t seem desperately interested and, as for the goat, watch the second video for our scientific taste test and make your own mind up.
Comfrey as medicine? A vernacular English name for comfrey is “knitbone” and medieval herbalists called it “bone set”. It contains a substance called allantoin, which promotes healing in connective tissue. Effective as it is externally, don’t take it internally, as it contains alkaloids, which can cause liver damage in large quantities.
Thanks to the following books for their information: Comfrey for Gardeners published by and available from Garden Organic (Henry Doubleday Research Association); Flora Brittanica by Richard Mabey; The Earth Care Manual: A Permaculture Handbook for Britain and other Temperate Climates by Patrick Whitefield and Wikipedia.
Thanks for this Stuart, it’s great! Couple of things:
1. Are you saying that you simply put harvested comfrey leaves in a garbage pale, put a lid on top, and let it sit till that goo shows up? If so, in the sun or out? and how long does it take?
2. I think the goat is trying to tell you it is not that he doesn’t like the comfrey but that he’s read Culpeppers and he’s trying to fix the tiny fracture at the base of one of his horns.
PS. Brilliant idea to put the tap at the bottom of the pale!
Same question as 1 above from me, if you will. I have the blocking 14 cultivar to prevent crazy spread and it is my only hybrid plant. I have it in huge and very deep containers to get full root development. It is one of the most attractive plants, I think, with those large leaves and little nodding purple blossoms looking down.
As for the goat, to me it looks like a cat with catnip in a way!
I bought some Russian Blocking comfrey several years ago for my patch. I do like using them for compost, I also throw a few leaves in each planting hole when I plant something.
I made comfrey tea one year and the smell kept me from ever making it again. It smelled like there were rotting corpses all over my garden, I can only imagine what the neighbors though, not to mention the constant gagging while trying to work until it all rained off. So a word of warning to those wanting to try to comfrey “tea”.
Bonjour, tout le monde!
Thanks for all your comments and questions. First up, une petite precision: It’s Bocking (not Blocking) named after a village in SE England which was the original home of the HDRA.
For comfrey “tea”, it’s just the leaves in the dustbin/garbage pale, stuffed in, right to the top. Do NOT add water, if you do, it really will stink to high heaven. I can’t remember how long it takes to decompose but I’m sure it’s only two to three weeks: just keep looking at it and when it’s reduced down, as in the video, it’s ready to pour off. Put the slimy residue in your compost heap or on the garden as a mulch.
Christy, have confidence that Bocking 14 won’t spread and put it into the earth, as opposed to a container. That way, it’ll get right down deep into your subsoil and mine those minerals, taht it won’t get in a container.
On your recommendation at your blog some time ago, we purchased the bocking 14 to see how it would do here in our subtropical weather. It’s as hardy as can be, and while it’s lush, it’s not appearing to be at all invasive. This year we hope to have enough to divide it and do some root cuttings, yay 🙂
Robbyn/thebackforty
I received some comfrey palnts that were from my great-grandmother’s garden. SO much great info on them here. Thanks so much & definately plant it where you want it forever. Wish I had known…
Where is the best place to buy either the plant or tea leaves? This info seems difficult to find.
Regard’s
al@xtek.net
Hi Al,
I live in France, so I can’t help you too much with sources, other than to recommend Richters Herbs, based in Canada, who sell the right sort of comfrey. The link to take you there is at the end of the second paragraph above.
You don’t need “tea leaves” as such, you just cut the leaves of established plants to make the liquid concentrate that people often refer to as comfrey “tea”.
Best wishes
We have have 5 goat kids with loose stools due to eating too many elm leaves and clover. Traditional scour medication was slow to act. We were advised by wise goat ranchers to use comfrey leaves to aid in our goats digestion woes. They had the same opinion as the goat in your video. We had to tear the leaves in half and place it in the kids mouth until they chewed and swallowed. After what seemed like forever and many attempts to spit the chewed leaf back in my hand, they went succesfully down the hatch. The smart kids pretended to swallow and spit them out around the corner only to start all over again. These people swear by them and gave me several roots to plant in my garden for the future. We will let you know tomorrow how they are doing. If this works I think I will try a food processor next time and squirt it down in a bit of water drench gun.
Hi Dawn,
Thanks for your comment. How did your young goats do on the comfrey medicine? I’d be very interested to know.
oh Comfrey! very good for Capsicums!
If using it early on in the season it combines well with worm castings to even out the NPK ratio that would otherwise be more generous in favour of the “K”, just dont forget to feed your comfrey too!
Thanks for your comment, Wesley. I no longer write for NDiN as, strange to say, even one blog a month was too much with all that we have to do around here and my own blog. Yes, of course, comfrey must be fed with nitrogen-rich fertiliser; we top dress fresh poultry manure. It’s very rich and I think comfrey is one of the few plants than can cope with it uncomposted.
I like your tip on wormcasts, thanks for sharing it with us.
has anyone heard of a variety of comfrey from South America? I have some seeds which I was told were from there and am not sure if I should plant them.
Dear Kristine,
Sorry that my reply has taken so long, it’s cold outside and I’m having a good sort out of my Inbox, when I came upon your message.
I don’t know anything about SOuth American varieties of comfrey but what I can say is that wild comfrey is a robust plant and can become a bit of a weed as it spreads from seed.
One of the main benefits of Russian comfrey is that it produces almost no seed, so is propagated by cuttings, so it stays where you put it.
My fear with the variety that you’re talking about is that as it clearly produces seed and so it might spread. because of it’s deep roots, it’s difficult to get rid of.
My advice would always be to stick to Russian comfrey that won’t take over.
Very helpful article – thank you! When making comfrey tea, do you put a lid on the dustbin?
Yes we do and remember, no water, otherwise it’ll stink.
Hi,
One of my uncles (who sadly is no longer with us God rest) was a very keen gardener, his forte being herbs.
Prior to his passing at a ripe old age he still had all his own ‘mass’ of hair and all his own teeth. He was a commando during WWII and escaped from POW camps on three occasions.
He would swear by the use of various herbage for health and persistantly spoke of the use of Comfrey to strengthen ones heart. With my own extremely varied knowledge over many subjects, l could only put this down to the seemingly high potassium content, which is also available in bananas. l hae been told by more than one doctor of the advantages of potassium in keeping ones heart strong and healthy and indeed various medications are available containing potassium to this end.
My uncle used to make Comfrey wine for human consumption and l have to say it was quite delightful and very strong. l found myself one morning, after just one bottle of the stuff, asleep upside down at the foot of the stairs.
l myself have not the inkling to undertake wine making but l hope this may be of interest and useful to readers.
Hi there , great article on comfrey , just a little question on taking root cuttings – do I have to have a leaf and a bit of root on my root cutting for it to take ? How small can I make the cutting to be successfull ? Thank you for this oportunity to ask a question and looking forward to the answer .
Derek
Hi Derek,
Dig up the entire plant: from the crown, split it into “offsets” each piece with its own growing tip (don’t worry about leaves as you’ll be buring the whole thing. Cut the tap root into 2 inch lengths. Plant all these bits of roots 2 inches deep, either in their new home or into pots for onward planting out.
Good luck?
Stuart
Thank you Stuart , have done what you said with my one comfrey plant , it hopefully should in a while become ten plants 🙂 . How long should my ten plants grow untill I can repeat the process ? I love this plant so much I want to spread it all over my neighbourhood .
Derek
I would leave the plants a full year before you dig ’em up and chop them into new root cuttings. If you have the intention to do this, you might not want to take many (any?) leaves from them–and certainly not towards the end of the season–so as not to exhaust the plant.
Experiment. Lift one plant after a year and see what you have root-wise before making the decision to lift the rest.
What ever you do, make sure you have the Bocking Russian Comfrey variety, so it stays where you want it. If it’s comon comfrey, you’ll have it everywhere without doing a thing (it’ll self-seed) and that’s not desirable, however much you like comfrey!
Thanks Stuart and Gabrielle , going to leave my ten plants in then – they are growing well as it is summer here will wait till spring – September to take some root cuttings , thanks again for the help – peace and love !
Hi,
Does anyone know if comfrey has ever been planted commercially? Thompson and Morgan in the UK sell a comfrey fertilizer that is pelletized and to produce volumes where could they be sourcing the comfrey from? Any thoughts on this?
Concerning Feeding and Veterinary value of comfrey for goats and other livestock: Fresh comfrey leaf contains about 20% protein and is excellent livestock food. Because it is hairy alot of goats/cows etc won’t like it absolutely fresh so thats an issue. If you let it wilt for 24 hours the leaf will become softer and more acceptable as fodder. Or, you can dry it and rub it through a coarse screen and add the herb to feed or you can mash or rub the fresh leaves and then they don’t feel hairy and most animals will then relish them. You can also mash and mix with molasses, which is good. Another point is that perfectly healthy goats may turn up their noses to comfrey but sick goats will eat comfrey as if it was one of their other favorite foods–fir bark, green hardwood leaves, some kinds of grasses or clovers, broccoli plants, celery, parsley, lovage, the labels from soup cans, grandpa’s cotton underwear… Comfrey treats scours, the usual stomach ailments, broken limbs, but not infections such as mastitis. If your goats however go COSTIVE then you truly have a problem and comfrey isn’t going to fix it. What I mean by costive is fully unable to poop and starting to bloat and letting out little plaintive cries–the goat will be dead in 2 days unless you get their bowels moving, call a vet.
Hi,
Just a quick query regards Bocking 14 – we ordered some 10 roots from Garden Organic last spring and have been very pleased with them. This year, although they’ve re-appeared beautifully fresh and green looking with plenty of healthy outside leaves on them we’ve noticed that following a good feed with chicken manure pellets some seem to be rotting or have a slimy area in the central heart of the plant. I had thought that Comfrey was a fairly robust plant and did not have too many problems (except slugs) but there is definitely something wrong-looking in the centre part of some of these plants.
Can anyone suggest where we’ve gone wrong with them please?
PS Thanks for all the great info about how to make the special Comfrey ‘tea’ above.
Hello,
This is a wonderful website, thank you !
I want to read it again; and add to the source list might a couple of good recommendations:
Coe’s Comfrey in Topton, North Carolina delivered some very large and healthy Bocking # 4 roots for an excellent price.
Horizon Herbs in Oregon sells
Bocking # 14; and my only experience with them is to say what good medicine their high quality organic leaf made for me last winter.
Good people and good plants.
Comfreygirl
wonderful.can any body help me to get the plants or seed in india?
Hello there I’m writing today as I’m in search of some answers on comfrey as a medicine.
Although as many say not to ingest comfrey , why is it ok to drink it as tea?
My main reason for knowing is that my dog has developed bone cancer and I’m in search of a way to help her, I’ve introduced yarrow into her diet along with raw foods only , and a dose of milk thistle and apple cider.
I want to use comfrey as aware of the benefits but seems it can be fatal ! Any suggestions your help would be greatly apreciated
Well, I think the simplest and quickest and least stinky way to get the most out of comfrey as a fertilizer is to put it into your worm bin. You can cover it up with soil or just leave it on top. I use a large plastic bin with a spigot near the bottom, filtered by a bag of gravel inside. Then water it down once or twice a day and collect the runoff as “instant” worm and comfrey tea. Works great, very little effort or time involved and no waiting. Just be sure to use “red wiggler” composting worms, leave the lid OFF of the bin if possible and do not drill holes in the bottom of the bin. Please anyone who tries this, respond to let me know what you think.
I can’t believe the volume of experienced gardeners in my area in the north of England that seem to be ignorant of values that comfrey plant have to offer in various horticultural uses ,esp. the sterile hybrid Bocking 14 (Russian Comfrey) that stays where you put it , probably the only fertilliser you may ever need , the NPK is claimed to be far greater than any of the normal animal manures , the tap roots mine deep down into sub-soil to bring main nutrients , minerals & trace elements through the roots into the leaves , I have one well established patch of 7 plants cutting 5-6 times a year , am contemplating on securing a second patch , as long as you carefully select your planting area & plant it where you want it to stay .