Grow Your Own Fertilizer Using Comfrey

, written by Jeremy Dore gb flag


When it comes to feeding plants, nothing beats organic compost.  Good compost contains the ideal range of nutrients which are released slowly into the ground as plants need them.  Often, however, there is a valid reason to supplement plants with a fertilizer, such as when growing in less than ideal soil, or in pots and containers where the potting soil can gradually lose its nutrients.  When choosing how to supplement plants the environmentally conscious gardener faces a dilemma: many commercially produced fertilizers are either chemical based or highly processed and shipped in difficult-to-recycle plastic bottles.  But there is one brilliant alternative that you can grow yourself - comfrey.

Comfrey is a large herb, native to Europe, which grows prolifically in damp places such as river banks.  As such, it can easily get out of control in a garden, so would not normally be deliberately introduced.  However in the 1950s the organic pioneer Lawrence Hills (founder of the organisation now known as Garden Organic) developed a strain of Russian comfrey named Bocking 14 which is sterile and will therefore not seed itself all around the garden.  To propagate it root cuttings are taken although these are best bought from a reputable supplier (such as the Organic Gardening Catalogue in the UK) to ensure that you get the Bocking 14 variety.  It easily roots and grows very quickly so it is best to plant it in its own bed to prevent it taking over an existing area.  [A word of warning: wherever you grow it don’t ever expect to eliminate it as its root system is very hard to kill]


What is brilliant about comfrey is that it contains high levels of all the essential nutrients for plant growth: Nitrogen, Phosphorus and Potassium (NPK) together with many other trace elements.  Comfrey out-performs manure, compost and many liquid feeds for concentration of nutrients.  It produces these from a deep root system extending right into the subsoil that most edible plants cannot access.  It also has an ideal Carbon:Nitrogen ratio which means that it does not hamper absorption of nitrogen by plants. When cutting comfrey it is advisable to use gloves as the hairs on the stems can irritate skin.

There are many great ways to use comfrey around the garden:

  • Mulch: Leaves can be cut and left to wilt for a couple of days before piling them around hungry plants such as potatoes and tomatoes as a thick mulch.
  • Dig in: Wilted leaves can be dug into ground that is being prepared for a new crop and will break down to give an excellent feed.
  • Liquid feed
  • Liquid Fertilizer: Comfrey leaves can be crammed into a large container with a hole in the bottom with a small container underneath to catch the thick black liquid which will be produced in a few weeks.  Weighing the comfrey down with an old brick will help this process and some people add rainwater but this does make the resulting ‘comfrey tea’ smell awful!  Once produced, the liquid should be diluted 15:1 with water before using it as a leaf feed for plants such as tomatoes.
  • Potting Soil: Comfrey leaves can be shredded and mixed with leaf-mold to produce a balanced soil for plants in pots, although it is a little strong for young seedlings.
  • Compost Activator: Adding high-nitrogen sources is a great way to boost ‘hot-composting’ if you have the right balance of green and brown shredded material.  Comfrey, being high in nitrogen, is ideal for this and should be well combined with the whole mixture rather than adding it as a layer.

Just over a year ago I planted some Bocking 14 comfrey root next to my compost bin and the growth has been astounding, despite it being a shady part of the garden that I would struggle to use for much else.  (Planting it next to a compost bin is a good use of space, as vegetable plants often get eaten by slugs near compost heaps but they leave comfrey well alone.)  I get three good crops of leaves each year from the plant, which can be cut right down to 2" above the ground and then re-grows vigorously.  Plus, the purple flowers are great for attracting beneficial insects.  Of course, I will need to keep a careful eye on it, perhaps splitting off some of the root every couple of years to prevent it getting out of control but apart from that it is so easy to grow.  The resulting leaves are perfect for mulching my tomato plants and help to suppress weed growth at the same time.  Comfrey really is nature’s answer to fertilizer for organic gardeners and best of all it is free – the perfect plant supplement you can grow yourself.

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Show Comments


"I have planted what was given me as comfrey but it has with flowers not purple. Is it not comfrey?"
Dorothy on Friday 5 June 2009
"It's good to know I can use comfrey for something useful! After reading your article, I'm going outside to mulch my tomatoes with it today. My half acre garden has been taken over by comfry and it is the bain of my gardening existence. When digging up the deep roots, each missed sliver of root turns into a new plant. It is hard to imagine anyone welcoming it into the garden but if it makes such great plant food, I will at least have some benefit. I would advise anyone thinking of growing it to make sure, as you said, to get a kind that doesn't seed. Also to be sure to keep it under control or it WILL take over. I can't imagine how I would get rid of mine. Do you have any advice for that aside from removing top two feet of soil and shipping it to a far away land?"
Ramona on Friday 5 June 2009
"Dee, I would dig it up if you are not sure, as it may not be the bocking 14 variety of comfrey and will spread wildly if it is the self-seeding variety. Non-fertile comfrey does not cost much and will be well worth buying."
Jeremy Dore on Saturday 6 June 2009
"Ramona, There are some strong weedkillers that are said to get rid of comfrey but personally I would not be happy using them. Instead you could try to get out as much of the root as possible and then continually dig up every bit that appears. Even then I think you will just end up controlling it rather than eradicating it, although perhaps the best thing is to see it as a positive plant food that can be harvested. Just don't use any flowering stems to mulch other plants otherwise it can root around the garden - just the leaves should be used."
Jeremy Dore on Saturday 6 June 2009
"I have comfrey growing along the fence on one side of my garden. As soon as the bumblebees are finished enjoying a flush of blossoms, I lop off the branches and toss them on my compost. That way, there is no reseeding. Keeping the plants along the fence, with mowed grass on the open side, keeps them in their place, too. Overall, though, they are not nearly as invasive as several other familiar plants, for example garlic chives or even tomatoes. I probably pull as many volunteer tomato plants as any other weed."
Barbara Pleasant on Saturday 6 June 2009
"Wow, Barbara, I wish I had your problem with tomato volunteers! Wish you could send them over here :-) Then again, I live in San Diego, essentially a desert... thanks for info on comfrey- very useful..."
Adrienne on Sunday 5 July 2009
"Chickens like to eat comfrey also, it is a great tonic for them :)"
Jan on Sunday 26 July 2009
"Dont forget about the pig's they can eat around 20lbs a day of the stuff and it does them a treat and they are effective eradicators of the plant roots and all"
Richard on Tuesday 18 August 2009
"I have been told by a lot of the old boy veg men on my allotment that 15 to 1 is too strong and can burn the plants and use 20-25 to 1 is a lot safer and still gives superb results."
david fountain on Friday 16 July 2010
"I live in South Africa and have just bought 2 comfrey plants. I put them in full sun, and in just half a day they have wilted, even though they had water. Is the African Sun too harsh for them, or is it perhaps that because they were re-potted they are still weak?"
Candice v/d Leek on Friday 8 October 2010
"Candice, I would recommend you keep watering them. Comfrey is very resilient and you may find that it picks up after a month or two."
Jeremy Dore on Saturday 9 October 2010
"Hi, has anyone ever seen comfrey grown commercially? I'm wanting to grow a field of it to add to my compost piles."
Lee on Monday 21 February 2011
"I have had a 'barrel' full of comfrey tea from last Autumn. While I will be using it to feed tomatoes and potatoes, can I use it for my other vegatables such as cabbage/broccoli/leeks etc. Also can it be used for plants in the garden ?"
David on Saturday 19 March 2011
"David, yes - at the right dilution it will be perfectly good for all other vegetables when applied as a foliar feed (watered onto the leaves). Just don't apply it for a couple of weeks before harvesting plants that you eat."
Jeremy Dore on Saturday 19 March 2011
"i'd like to use comfrey for animal feed/fresh and in hay for rabbits and goats- i read about it sometime in my past but can't seem to find anything about how much or any side effects of feeding to much or if the horses get into it or other livestock, does anyone feed it to their animals?"
linda fawcett on Monday 11 April 2011
"Linda, I think comfrey is well established as a fodder for poultry, and for rabbits and goats in moderation. Here's a link to Harvey Ussery's take on it. He's a wise and experienced homesteader:"
Barbara Pleasant on Monday 11 April 2011
"I saw a bag of dried "Comfrey Tea" in a local natural market. Can these dried leaves be used to fertilize my plants as well? Is it better to soak them in water and use the liquid to feed vegetables? Interesting article - I have been looking for a way to fertilize my tomatoes naturally. "
Dorian on Monday 16 May 2011
"If the dried leaves are 100% pure comfrey then yes, you could use them to fertilize your plants or as a mulch. However, since they are already in a form which makes them easy to use as a liquid feed you will probably find you get more benefit from soaking them and watering it onto the plants' leaves."
Jeremy Dore on Tuesday 17 May 2011
"I have two dobermans and they love eating Comfrey especially the young tender leaves on our land it grows next to a burn, they also eat Cleavers (Goosegrass)quite happily, it is virtually part of their daily routine, I call it their cabbage patch :-) "
Gillian on Thursday 15 September 2011
"Can comfrey be grown successfully in containers?"
Donna on Friday 4 November 2011
"I used comfrey leave green a couple of inches in the bottom of each hole then lined the hole with it right up to the surface of the soil then poke some holes in it with a small stick or simalar or it will stop good drainage and muck up the soil then put a little soil in it and put your tomatoe plant in and fill with soil then water periodically with 9 parts water 1 part milk plus aspoma 3-4-5 fertilizer periodically and water periodically with the compfrey solution I had fantastic tomatoes abundant fruit very healthy stalky plants some grew 8 feet I had to top them they were totally virus and desease and drought resistant and were the best unequaled plants and fruit set and large and medium fruits the best in connecticut I ever saw try it I will garuntee total success oh sorry by the way I also put 1 tablespoon of epsom salt in bottom of each hole and previously had used dolimite pelletized lime on garden and also put bone meal in each hole and bone meal thinly scattered in whole garden this combination is fantastic for mostly all your plats in the garden please believe me I am liveing proof if you want more info contact me at thats my personal address I will be glad to give you any further info my name is georgie bouthillier my yellow tomatoes were still producing late into the cold season aswell as my winter squash and zuccinni was medium and large out of site I sincerely HOPE THIS INFO HELPS YOU GLAD TO ASSIT YOU IN ANYWAY I CAN"
GEORGIE BOUTHILLIER on Sunday 27 November 2011
"sorry I for got I also mulched with green comfery and shredded some up and mixed it in whole raised bed georgie email is drop in anytime i will respond with other helpful experienced input if you so desire"
GEORGIE BOUTHILLIER on Sunday 27 November 2011
"georgie sorry again I planted borage near my tomatoes and absolutely had no pesty bug problems plus borage improves the flavor and health of the tomatoe plant and attracts ton of bees"
GEORGIE BOUTHILLIER on Sunday 27 November 2011
"I am planning on growing comfrey for my eggers, I mean chickens. I am glad to read that dogs can eat it, my dog likes to sample greens to figure out what he wants to eat. I live on a half an acre full of weeds and figured I would like it if comfrey took over. But upon reading that someone on the same size land is over ridden with it maybe I will get the blocking type so I can grow other things too. Does the non-blocking type spread by roots? I do want it to spread some."
Je9Jeanine on Sunday 29 January 2012
"My (very healthy) dog loves to eat comfrey leaves. Does anyone know why?"
Duncan on Saturday 5 May 2012
"Try crushing a comfrey leaf to bring out the sugars and rolling it into a ball, leave it near the plants that the slugs are eating, they will go for the comfrey leaf instead, a night time hunt should help deplete the numbers of them"
Angela on Tuesday 8 May 2012
"Try crushing a comfrey leaf to bring out the sugars and rolling it into a ball, leave it near the plants that the slugs are eating, they will go for the comfrey leaf instead, a night time hunt should help deplete the numbers of them"
Angela on Tuesday 8 May 2012
"Try crushing a comfrey leaf to bring out the sugars and rolling it into a ball, leave it near the plants that the slugs are eating, they will go for the comfrey leaf instead, a night time hunt should help deplete the numbers of them"
Angela on Tuesday 8 May 2012
"Jeremey Can you please change your email contact to me from blueyonder to Thank you David"
David Fountain on Tuesday 8 May 2012
"Can I use it for my grape vines too"
Carol on Thursday 21 June 2012
"Last year I never got round to emptying the barrel in which I make liquid comfrey.I have used the liquid to feed my tomatoes this year and the leaves have started to droop.I wondered if the old comfrey could have burnt the roots.Has anybody got any thoughts?"
Pete Tennant on Wednesday 18 July 2012
"I do mission development in South Africa and planted several comfrey plants near the chicken fence so they could eat it when they wanted. They loved the plant, but when I butchered the chickens which looked very healthy the liver which indicates the internal health of the chicken was very poor - rather poor color and very fragile. In 2009 we found out the government had put a restriction on it for human consumption because it damaged the liver. These same plants we used did not seed out but we propagated by root. We helped many people who had scabies by putting some heat wilted leaf on the scabies sore. Within a day or so there was marked change and sometimes complete healing. It also works for bruises. It is best to put a thin cloth on the skin before applying the comfrey because it does cause some irritation. There was a comfrey grower in South Africa that indicated there are two varieties of comfrey - one is edible and the other not. Does anyone have knowledge about the edible one and what variety it is. This plant is so good for the poor since they can grow it. "
Thandolima on Saturday 21 July 2012
"I've been told that there are 2 types of comfrey in SA, the sterile Bocking 14 and the common/wild comfrey that can spread via seed. Both propogate easily from root cuttings. I have both but I haven't seen evidence of the common comfrey spreading via seed. Most scientific literature warns against human consumption of comfrey, but it is used as animal feed. I have as yet to find a nurserymen in SA who knows exactly which cultivar they sell! "
Leanne on Sunday 29 July 2012
"Just discovered this excellent thread on a plant I have known since childhood and that means over six decades. I have several plants in a small middle England garden and use for medicinal as well as horticultural purposes. I am willing to share what little knowledge I have accumulated via this blog, starting with an explanation that Bocking 14 is one of several varieties grown and catalogued by Lawrence D.Hills back in the 1950s and named after a now defunct site in Bocking, Essex,UK. This was an important milestone in the growth of the Henry Doubleday Research Association which is now better known as Garden Organic and has its own 10 acre development centre and a website. I should point out that I am not a member of any organisation and that my opinions and recommendations are simply based on my own interest in, and usage of, Comfrey. I also have fingers in many other hobbyist pies so be patient regarding my responses to any questions aimed me. "
Mr Pomfret on Friday 8 February 2013
"Comfrey: Home Grown Fertilizer Holy... I have found my soul mates. I moved to a house with two acres and a plant that had taken over much of the garden and was impossible to eliminate so I decided to live with it. Good thing. I first noticed it seemed impervious to insect damage, slugs in particular, and mulched my tomatoes and other garden plants with as much as I had. It worked but I also noticed the tomatoes were bigger, healthier, better fruit...the whole nine yards. OK...I'm diggin' this. I started planting with comfrey right from the get go. I am a bit of a lazy gardener but mostly just always have a few dead plots that get weedy...and soon start sprouting comfrey!!! I scatter plant a lot of the small seeds like lettuce and basil and in Hood River the wind will scatter some no matter what. Interestingly, I had a huge differential in the survival rate of seeds that fell in the weeds versus those in the prepared bed. was the weed bed that some how protected the seedlings. I am theorizing the native or adapted plants have some chemical repellent that disguised the tender basil shoots. Worked subsequently with beans too: Both plants are slug targets for sure. When I first figured out what the plant was I read that it was used as thoroughbred feed: high in protein, nutrients etc because the roots grew so deeply. I have dug some up over two feet down into some hard Oregon ground (I live in a place locally called Rockford for a good reason.) My mule loved it and the chickens go bonkers. Cheap feed frankly and the eggs are amazingly rich shortly after they have a few days on it in the spring. I could go on...but glad to have found you."
Daniel Baxter on Saturday 13 April 2013
"hi is the comfrey liquid feed only to be used as a foliar feed, sprayed on the leaves?? or can it also be used to water the plants with(root feed) "
jack brown on Tuesday 23 April 2013
"As long as you dont over do it it is edible in moderation for Gods sake carrot top are loaded with vitamin (A) and is exellent for you but if you consume to much Vitamin (A) it is poisoous to you and carrot tops are concentrated with it so just limit how much you eat that is a known fact it is not poisonous unless misused so comphrey is the same thing I forget what substance it is that is in it but it is good for you also help bones to heal better but you have to drink comphrey tea in moderation or it will be bad simalar to carrots also if you can get beyond the fuzziness of it boil and steam it and eat in in small amounts now and then if you research it you will find this is true and stated on articles on it with those who are well informed and knowledable of this in a profressional open minded way and as far as the state or federal government is concerned I do respect and honor them greatly and will back them on most all their wats but sometimes when it comes to a food source they can be pig headed think about it they allow pestcides and fertilizers to be used that slowly poison and ruin the enviorment and allow this to be used on soil and the foods that we grow our food on and eat that food so be careful on who you listen to when it comes to precious healing herbs that is said to be totally bad for you when I truely believe what should be stated is that some of theses herbs or foods must be used in moderation then they will be very beneficial to you and be careful not to use large amount similar as to carrots or they have a tendacy to toxify your system think about it if you use a prescription medication as directed it helps you but if you take alot more then they tell you too without proper direction it possibly could kill you"
george on Wednesday 24 April 2013
"Well jack brown I dont know about the comphrey liquid feed you said you have if you bought it but one thing im sure of is I have a large comprey hedge in my yard and pick alot of fresk leaves as directed by organic gardeners and specialist in this:you can soak alot of them in a little water mix in some powdered fat free dry milk some unsulfured molasses and cover it and let ferment for 2 to maybe 4 weeks then you start to take some of the liquid out when needed and cut it 20 parts water to 1 part comfrey concentrate water your soil directly around the plants any of them they love it the reason it is so good is comfrey root grows deep deep deep into the earth and draws up a whole lot of trace minerals into it as well as having other good nitrogen phosphorous and potassium levels in it it becomes very concentrated so be sure to dilute it with 20 parts water when used sometimes I cheat and dilute it 10 to 1 all my plants did fantastic tomatoes ect.P.S.if im not mistaken the powdered milk kind of nuetrilizes the smell as it ferments be it cover but periodically uncover for short period and stir this will give it oxegen and feed the necessary bacteria thats needed to break it down to make it available to the plant also "
george on Wednesday 24 April 2013
"Pete Tennant I going to take an educated guess cause I use comfhrey like you aswell and never have that problem the fermented mixture after 4 weeks is very concentrated and they tell you to cut it with 20 parts water when you use in on the plant you had yours in there very much longer so you could be superman concentrated and you have to dilute it with maybe at least 40 parts water maybe up to 60 try it but I would try it on only a couple at first just to make sure you didn't have an unfreindly bacteria or virus grow in your solution cause you had it in the barrel for such a long period of time if you dilute it 40 to 60 parts water and plant does well and does not droop its leaves your fine and use it on the other plants but if it damages the plants with a large amount of water added dig up the plant and throw it out and the root ball and then disinfect your barrel with large amounts of vinagar mixed with borax soap that has boron in large amont will kill the bacterria and virus that is attacking the plant and by the way dump the borax and vinagar some where away from the garden cause a high concentration of boron will kill plants so will vinegar"
george on Wednesday 24 April 2013
"ok thanks george. so it's definately ok to water the roots with sufficient dilution? just wondered why everywhere i read, it only ever mentions foliar feeding and not root feeding."
jack brown on Wednesday 24 April 2013
"Jack you say every where you read it only mentioned it as a foliar spray or foliar feeding that is sad maybe you just did not come across the more essential detailed uses of comfrey in all around garden and plant use as well as the very healthy limited consumption of it tea made and drank limited amounts aswell and of coarse to mention a poltice made from the leave that have been steeped in hot water then put the compress on a sprain or sweel relieves it and draws poison out from what I heard I use it it is also called bone knit herb loaded with calcium Ivv drank the tea used the poltice and my bones healed fast and fantastic of coarse after I went to the doctor and had them look at it and set it if it were a compound fracture and also the leave make a great mulch in the garden it robs no nitrogen at all when it readily decomposes but actually almost immediately adds it I lined it in my plants hole pocked holes in it for water release put my tomatoe in hole with a couple other admendments and my tomatoes were unequal in the entire state of connecticut I never had such a fantastic crop in my life plus the were almost bug free and had absolutely no health problems and were uneffected by drought and dry periods there is so much to share but I must stop now I could write pages on it with my successful use of it old timers years ago turned me on to it and its also in the book back to edan used with natural pathic healing its worked for me as a person and it worked great in my garden plants in a damp area where you can let in take over and you will have an endless useful supply and never have to buy comfrey again or the comfrey extract again for your garden you will have all you need make your own and also use it as a mulch and a great compost activator loade with nitrogen that is needed to feed the bacteria that break the material down into useful compost Im george email is drop me a line we can communicate you can help me and i can help you if you need more info"
george on Friday 26 April 2013
"Hi - can you tell me if there are any veg plants that you shouldn't put comfrey fertiliser on. "
Wayne on Wednesday 17 July 2013
"I've just come in from the garden and was shocked to see my four young comfrey leaves were munched away in one afternoon. I old German shepherd ate them. I assume it isn't poisonous to eat four leaves? curious...Jen."
jen on Saturday 20 July 2013
"My question is this: If I plant a Comfrey plant next to my young scrawny struggling Mexicola Grande Avocado tree, will the tree derive any benefits therefrom just by growing next to it?"
RowBear on Thursday 29 August 2013
"When I've used comfrey too neat on my tomatoes I've had blossom end rot,to combat this I watered well for the next 4 weeks and used comfrey 20:1 , I used the mix once a week and had my best crop ever"
Mike seadog on Monday 9 September 2013
"I live in Sydney Australia and I have extensive back yard gardens. My garden enjoys the benefit of comfrey. It really goes to work in liquid form, accelarating growth and yeild.I highly recommend the use of this lovely plant which I like growing along my fence and also I give the leaves to my chickens."
DON on Tuesday 5 November 2013
"How much comfrey should I grow to feed 1 tomato plant? I'd like to work out how much space I should dedicate to Comfrey growing if I wanted to feed 18 tomato plants over a full season."
greenfingeredG on Saturday 5 July 2014
"GreenfingeredG, it depends on how long your summer lasts, but you should be able to get three harvests from each comfrey plant. I have six mixed Bockings (four with violet and two with deep purple flowers) and these collectively produce about five litres of strong black liquid over the growing season. I use it as I go along so it's difficult to be accurate but there is easily enough to feed 18 tomato plants using a 20:1 dilution. I compress the leaves in a milk churn, open-topped to allow rain water in. However, while waiting for the first leaves to rot down to liquid form, I let a few handfuls wilt for a few days and then spread them around my tomato stems so that they gradually leak goodness into the soil where it needs it. This adds nitrogen as well as potash and guarantees healthy fruit growth. I can't be certain but, in my experience, the liquid form is best used once the fruit has set, e.g as trusses, otherwise it will stimulate too much leaf growth. Works wonders with my strawberries as well but when feeding, avoid adding directly to the berries and wet the surrounding soil instead. "
Mr Pomfret on Sunday 6 July 2014
"I tried the Comfrey tea but I'm concerned that it is anaerobic as evidenced by the ghastly smell and I question the use of an anaerobic tea on or around any plants. Any scientific or good experiments known on this?"
Bonny on Thursday 19 November 2015
"Bonny: I have never heard the word 'anaeorbic' before and neither is it mentioned in Lawrence Hill's authoritative book 'Comfrey - Its Past and Future'. Mind you, it was published in 1976 but is packed with scientific data gleaned from extensive research over a long period.The only reference the author makes to the smell relates to silage making which farmers accepted as a by-product of the high protein content while slowly breaking down.This was later alleviated by adding molasses or by using the addition of certain acids (A.I.V process). If this sounds too highbrow, my next door neighbour used to boast about his tomatoes always winning prizes in his local garden competitions during World War Two. He confided in me that he used to fertilise his plants not with comfrey, but with the produce of his family's outside lavatory and it can be assumed that the aroma did not carry into the judge's tent. As Wordsworth wrote "We murder to dissect". I would advise not only you, Bonny, but all of you to Google this quote and read the whole poem. "
Mr Pomfret on Thursday 19 November 2015
"I have read that common comfrey can cause medical issues to a human's liver. I hope not because a use it in my composter. Anyone have a update on the use of comfrey in the garden?"
Joe Mota on Wednesday 10 February 2016
"Joe, to clear up any apprehensions or misapprehensions about medical issues, take a day off and read the rather lengthy but thorough article on comfrey, as follows: For many years I have made root extract ointments and tinctures for relatives and friends and nobody has suffered any side effects. Though I personally feel it's unnecessary, I play safe by printing "Not to be used internally" on the label. However, I do include "Not be used on broken or bleeding skin" in the instructions because it will quickly heal the outer surface and seal in the root cause of whatever damage or infection lies beneath. To directly address your worry about composting, you can add as many leaves and stems as you like to the bin. It's protein-rich and rots down amazingly quickly, adding potash and nitrogen to whatever else is in there. "
Mr Pomfret on Wednesday 10 February 2016
"COMFREY POWDER. My comfrey has spread at an alarming rate, invading native species around my stream and jumping out of my property so I have felt a bit panicked since it is out of control. I have decided that I should try comfrey powder as a fertilizer. To me it sounds better than compost tea because it seems like it would take less space, it has no odor, and can keep for much longer. I am not sure why there is not much info out there about using the ground dried leaves. I am not sure how much powder I should use? I would appreciate it if someone could help me with this. Should I dilute the powder in water before watering garden or should I sprinkle it straight on the garden plants ( around base)?"
A.CIsnes on Sunday 21 August 2016
"A Cisnes -you are have two challenges to face: the first one refers to your comfrey getting out of hand. It most likely originates from the same plant sprouting in different directions so trace the stems back as far as you can reach under the soil and dig out as much as you can of the root. Either that or borrow some goats or pigs to clear it for you - you will produce some excellent milk, cheese or pork that way. Unless you use the root for medicinal purposes as I do, put it in the council garbage bin but keep the leaves for composting.I have my comfrey compost bin away from the house to avoid the smell and use the black liquid from the leaves as a fertilizer (see my previous post). Comfrey powder is normally made from the root so I have not heard of leaf powder and don't see the point of it making it. However, I would guess that any comfrey powder should be treated like fish bone granules and worked into the soil when planting out your fruit or veg. This should gradually release nutrients and help the retain the life of whatever compost you use as a home for your crops. "
Mr Pomfret on Monday 22 August 2016
" For Bonnie - Anerobic bacteria multipies when there is an absence or little oxygen. This will smell badly. If the water is aerated like a fish tank the solution will develope much desired bacteria which are very beneficial to the soil and plants. "
Thandolima on Monday 22 August 2016
"The idea of comfrey powder is interesting, but it might be more practical to come up with a way to dry the leaves so you could have them for composting at all times. "
Barbara Pleasant on Tuesday 23 August 2016
"I agree with Barbara that dried leaves will work just as well as powder but if you need a quicker change to the planting medium, do what I did yesterday. I sieved and bottled the liquid from my leaf compost container before scooping up the residue and placing clumps around the base of my now-fruiting tomato stems (I am in the English Midlands). This mulch doesn't smell once its exposed to the air and will inject an immediate hit of potash and other nutrients vital to the development of tomatoes and similar crops."
Mr Pomfret on Tuesday 23 August 2016
"I have had comfrey for many years and have managed to keep it under control by using it frequently. The root dug and scrubbed and ground up with a little water in the food processor can be used as a poultice for bruises, strains, sprains, possibly even fractures. The roots contain allantoin which is proven to assist in wound healing. The paste will keep about a week in the refridgerator. But I'm still not convinced about " comfrey tea". "
Bonny on Tuesday 23 August 2016
"Hi All, I have just read through previous contributions. I live in the Scottish Borders and have used Comfrey for 20 odd years. I started with Bocking 14, but then accidentally introduced a non sterile strain, so it does self seed. If used frequently (i.e. before flowering) then this should help cut down the spread, but once established it is virtually impossible to eradicate fully. I work on the basis of cropping vigorously and digging up as much root as possible and this more or less keeps things under control. I find that having a "better half" who expends great energy in reminding you how useless you were in allowing in the non-sterile Comfrey in the first place helps immensely. I think water should be avoided, which greatly reduced the issues of smell. I use an old bin with holes drilled in the bottom and put in the leaves, compressed with a large stone. Within a few days the liquid starts to drop into the tray below the bin and within a couple of weeks all the liquid has been extracted and the remains of the leaves go on the compost heaps as an accelerator. We then turn to usage. Plants need water and they need feed, they do not necessarily need them applied at the same time. I water my tomatoes, Sweet Corn and Asparagus as I think they need it. I apply Comfrey liquid as they need it, always on to damp soil. This massively reduces the smell issue. An earlier mention of bottom end rot on tomatoes is attributable to and irregular watering regime rather than anything to do with the Comfrey feed. I find that I have a very good success rate with the above. So, Golden rules 1 - Use only Bocking 14 if you can 2 - Extract liquid without using water 3 - Treat watering and feeding as two separate, but essential, regimes. 4 - Enjoy healthy crops. Mike "
Mike on Thursday 6 October 2016
"I fully endorse Mike's advice on usage and we are not alone in valuing it's benefits to fruiting and soil enhancement. I recently visited Nunnington Hall in North Yorkshire where the gardeners grow Bocking 14 in a designated plot to avoid it spreading. They drip water into leaf containers and pipe it well away from visitors' noses for use as their main fertiliser. The flowers, shrubs and fruit are literally a joy to behold, adding extra charm to the grounds of this old manor house. I should add that comfrey is similarly used in even more elevated society, namely by the gardeners at Prince Charles's Highgrove House. You can't get a much better endorsement than that. "
Mr Pomfret on Sunday 9 October 2016
"Is there any plants that you should not fertilize with compfrey?"
Cindi on Thursday 29 December 2016
"Hi All, I prefer to think long the lines of feeding the soil and then the plants just take what they want and leave what they don't. Comfrey is an all round feed, with a bias towards helping Fruiting and roots. Before Comfrey is ready in the year you can use nettles in exactly the same way and this produces a liquid higher in Nitrogen, which is good for leaves, so handy for growth at that time of the year. We have produced large numbers of plants for sale at our local horticultural society for over 20 years and for sales at our own garden for the last 5 years when we have opened under Scotland's Gardens. Our plants are fed with Comfrey and we frequently have comments about how sturdy our plants look in comparison with similar fed on commercial composts."
Mike Madden on Friday 30 December 2016
"Cindi, there is some useful advice on the following site about potash-hating plants: Mind you, I spread rotting comfrey leaves at random to enrich the soil but it's safer to avoid using liquid fertilise on the leaves and flowers of acid-loving plants. "
Mr Pomfret on Saturday 31 December 2016
"Hello this is to Pete Tennant who used his soaked comfrey leaves from a barrel he soaked last year that he had left over!When you soak anything it becomes very concentrated especially comfrey and it must be diluted at least 20 to 1 with water or it can damage the plant!Also when you have it in the water way to long it becomes anarobic bacteria riden which is a bad no oxigen bacteris that is poisonous to plants at high doses which you did!When you have very old soaked comfrey leaves and that liquid it is best to throw it out or you take a very high rish of killing your plants or making them very sick which you did by accident!It is on of the best natural fertilizers in the world but you must try to use the liquid in about 6 weeks cut 20 to 1 the longer it is in the water with no air circulation it becomes anarobic which is damaging to plants but that goes for anything you soak in water for long periods of time!Good luck and continue to use it but do it as I suggested!"
George B. on Monday 29 May 2017
"Hello for a few years now i have used comfrey as a liquid fertilizer and i have always believed that it has really helped in growing my small crop and flowers. I went to my allotment today and as i gave it a good stir i noticed lots of white lavra in my liquid bin. I have never noticed them before and was wondering if this was ok? They were about 10mm in length and seemed to have a slight white strand or tail attached to them. I'm just a bit concerned about them as i would have them to damage my crop and flowers. Any ideas what they are. Thank you"
Riley on Tuesday 30 May 2017
"Riley, please search "rat tailed maggot" and see if it is a match. These are larvae of beneficial flies, and should not hurt plants. "
Barbara Pleasant on Tuesday 30 May 2017
"Hello Barbara Many thanks for the information. After checking, yes they were rat tail maggots, panic over kind regards"
Riley on Wednesday 31 May 2017
"Hi you say dilute 20to1 do you mean watered down comfrey or is that the liquid form ?"
Rodney Arnold on Tuesday 15 May 2018
"I understand your confusion, and after studying George B's reports above, I'm pretty sure he is saying to dilute the concentrate 20:1. "
Barbara Pleasant on Tuesday 15 May 2018
"Hi all, With recent comments I felt that maybe an update of my position might help. I had access to very large amounts of Comfrey and I would pack my "rubbish bin" absolutely to the top and, during hot summmers inside a polytunnel I would be filling plastic bottles with neat Comfrey most days. I was therefore very liberal with it's use on very infertile soil. Over a couple of years I had very heavy crops of tomatoes, sweet corn and peppers and all had above average taste. When I left that environment I took about 30 or 40 four pint milk bottles of Comfrey liquid with me (say 15 - 20 gallons) and, even used very sparingly in my tunnels at home, they have finally run out. Despite the fairly fertile soil in these tunnels the above crops, plus my 20 year old Asparagus, are cropping at greatly reduced levels. This is only my personal experience and, although I appreciate the space required to produce large amounts, I would say that Comfrey liquid is an exceptionally good feed. Mike."
Mike Madden on Tuesday 15 May 2018
"when I say 20 to one that is when you soak a barrel with comfrey in it about 2/3 comfrey and 1/3 water for along time and I stir it daily with a long stick to keep a fresh oxegen supply in it !But you do not have to go thru all that all I do now is have about two 40 gallon platic garbage cans by my garden and fill then with water and add about 1/4 of that barrel size with my chopped up comphrey and let it ferment for about two weeks but be sure to add about a cup of unsulfured mollasses this helps break it down by assiting the bacteria growth that breaks it dond be sure to stir it with a long stick 2 or 3 times a day to make sure it gets a good oxegen supply then you do not need to use the 20 to 1 ratio I use it directly like that to water my plants starting at the 2 week soak and use it till one barrel is gone then go to the next barrel that is full and start a fresh bach in the barrel I just emptied its easy all you need is two 30 to 50 gallon barrels by your garden to keep up on the rotation when one barrel is used up all I do is have a long garden hose that reaches to my garden and leave it there all the time to fill the barrels and water my plants also it is better to take 1 liter sode bottle or 2 quart juices bottles,or 1 gallon milk containers and drill about 4 1/8" holes in the bottom and 4 about an inch up on the sides insert them in the soil about 3" by the plant and fill them with your water or liquid feed for you plants its better that way it goes in soil slow but sure and it keeps diseases away from your plant that you gat from surface dampness on your soil plus there is no run off and it penetrates slow but deep to encourage a good rooting system!"
Georgie Bouthillier on Wednesday 16 May 2018
"P.S Sorry I shuold add I am sure I do not put 1/4 I might put in max about 2 gallons but if you want it to break down alot quicker to become available do as I do and I take the comfrey in the house take the knife chop it up small then put water in the blender chop it all up in the blender then I dump it in the barrels when they say a 4 week soak that is pretty much whole leaves of comfrey it breaks down extremely fast when you chop it up into small pieces and add molasses to the recipe"
GGeorgie Bouthilliereorgie Bouthillier on Wednesday 16 May 2018
"Hi I have bought a comfrey plant but it is not Bocking 14, I intend to put it in a large pot, can I still use the leaves to make fertiliser? My plant is Sphytum officianle? Thank you for your time Kind Regards Carole Dalton"
Carole Dalton on Thursday 7 June 2018
"Hi Carole, Any Comfrey makes excellent liquid feed. Bocking 14 is infertile and so will only spread slowly. Other Comfeys produce seed, which spreads everywhere and so is, effectively, a thug. If you grow your Comfrey, you can let it produce flowers, which are a massive attraction/ feed for bees, but then cut them back before they actually seed and you are on a par with Bocking 14. Should you wish to buy Bocking 14 then I think that the only trusted supplier is Garden Organic at Ryton. I started out with Bocking 14, but accepted other plants (which were obviously not) and they are controllable....ish, so all is not completely Black or White. Mike."
Mike on Thursday 7 June 2018
"I would just to Mike's comment that Comfrey also spreads from any fragments of root left in the soil. "
GreenfingersG on Thursday 7 June 2018

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