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Making Comfrey Liquid Fertiliser

Apr 07, 2010

This is my Comfrey liquid making system. The upper container which is packed with comfrey leaves has a hole in the bottom. As the comfrey decomposes a dark brown liquid drips out of the top container and into a plastic bucket inside the lower container. The leaves in the upper container are covered with a plastic sheet, steel mesh and a stone. It takes about a month in summer to totally rot down. I will get about a gallon of concentrate from one container full of leaves. When used the liquid is diluted about 10:1 as a liquid feed. [ To the colour of weak tea] You can use it as a foliar feed or pour it on the soil. The biggest advantage of using this fertiliser is that it is FREE!!!! The type of comfrey i use is Russsian Comfrey [Bocking 14] which is sterile and will not seed itself around your garden and become a nuisance. If you want to learn more about this type of comfrey then google the name 'Lawrence Hills'.


Hi Glenn, Do you imagine that you will still get those spiny soldier fly maggots in that open bucket? I gave a friend some tea to use on his bio-dynamic organic dairy cow. She had hoof rot and he irrigated with tea following his normal treatment, it seem to have worked. At least, she is up and about much better. Thought you would like to know that comfrey has more uses than a compost starter and as a source of potassium. I noticed a marked smoothness to my hands after I harvested last Fall. I plan to divide one of my five plants this spring. I want to see how it will do as living mulch at the base of my windbreak trees. They are drip irrigated so there should be no problem with ample water. I always treat the windbreak with Castor oil to preclude root eating pocket gophers and, then foliar spray fertilizer once the leaves are well out. Your friend, Mike DeLate, Tetonia, ID USA
That looks interesting. ? used comfrey for a liquid fertiliser but just threw it into a large container ie plastic rubbish bin and added water then left it for about a month in the sun. ? will have to try your idea in the future, thanks.
Thanks Glenn, I like your technique better than mixing leaves and water. I'm just guessing, but is that top container 16" or so in diameter? We just got another 10" of snow and Buckwheat brought a friend to my bird feeder. Tomorrow the State Dept of Ag is putting on Organic Producers Training course in Blackfoot (1 1/2 hr drive). This will be the first of any training on this side of the state (300 miles distance) & most welcome. I take it that Lawrence D. Hills is the father of Organic Gardening in the UK. Mike
Hi Mike I think the top container is an old automatic washer drum. It is difficult to scale a photograph i know, but i think the drum is about 2' - 6" diameter. The advantage of this method is that you end up with concentrate, which takes up less storage space. The bottom container is what is called a 'Dolly Tub'. That was a washing method from the time before washers were invented. You put your clothes in the tub with soapy water and bashed them with a special wooden implement or 'Dolly'. I like to recycle things. I don,t know if they sell 'Baby Bio' in the states. This is a houseplant fertilizer that they retail in tiny little bulb shaped bottles at a heck of a price. I am almost certain that Baby Bio is comfrey liquid as they look identical. The home of organic gardening in the UK is at a place called Ryton Gardens. The organisation used to be called the 'Henry Doubleday Research Association'. Nowadays they call it 'Garden Organic' which i suppose is a bit more to the point but lacks the kudos of the original name. I have been to Ryton gardens a couple of times, but it is 150 miles away from us in Coventry. Good luck with the gardening. Glenn
Hi Glenn, Thanks for the recipe. I started my comfrey from seed this year, it'll be planted between the grape vines away from the vegetable garden. I look forward to making the fertilizer.
Hi Everett Comfrey has brittle roots which dive deep into the soil looking for goodness. Make sure that you plant it in a place that you know for certain it can stay. It is very difficult to eradicate without using weedkiller, if you find it is in the wrong place. Also watch out for it self seeding. I managed to obtain a self sterile strain [Bocking 14] which overcomes the problem of self seeding. I bought small root cuttings by mail order. Have a great day. Glenn
Hi Glenn, I just bought Fertility Gardening by Lawrence D. Hills but couldn't find any other old "All Muck and Magic" broadcasts, except one on wine. Considering the way that my comfrey grew last year, I should have plenty. I want to grow it around the base of my windbreak trees as a living mulch and then cut it. They cautioned me about tilling beds with comfrey in them. I was sent roots to plant early in the season. Which means that seeds aren't the only method of propagation. Apparently, one should be cautious. The snow melteth away! I very much admire your commitment to recycling, that washer tub was inspired. Mike
Hi Mike I remember watching those old programmes years ago. They were filmed at Ryton Gardens. I have a number of old gardening programmes on VHS and DVD, but i don,t know how to get them uploaded onto the internet. I think i will have to start a blog and get some feedback on how it can be done. Regards Glenn
My old comfrey collector was stolen, so this is the slightly tidier idea. This consists of a large upper container [Green Dustbin]which sits on a stool. Their is a 2 inch hole in the dustbin. The liquid drips out of the hole in the dustbin into the bucket below.The barrels to the left are for rainwater collection to save walking to the tap which is 50 yards away.
I found this site which i thought was very interesting.
Comphrey could be a globally robust garden-friend for soil building & I am so happy to see the relatively high organic fertilization comparison from the website > The chart copies perfectly into the text box but loses the chart form when I hit Save. I think I will leave it anyway, since it is not that hard to see the five fertilizer components compared > Comparative Nutritional Analysis of comfrey, compost and manure Material 1. Water % 2. Nitrogen (N) % 3. Phosphorus (P) % 4. Potash (K) % 5. Carbon-Nitrogen Ratio Farm Yard Manure 76.0 0.64 0.23 0.32 14 - 1 Wilted Russian Comfrey 75.0 0.74 0.24 1.19 9.8 - 1 Indore Compost 76.0 0.50 0.27 0.81 10 - 1 I hope to weigh in on the composting system for The Hope Garden, which is not yet set up. In your compost-essence-process that you describe above, can you tell me what kind of an odor factor you get, if any? And have you ever considered throwing some visqueen over it to warm up the process to compost temperatures? maybe speeding the process? Not sure what speed would have to do with garden time ... :-)
Hi Jessica I am going to fly in the face of tradition and say that comfrey tea, when made as shown above does not smell. Generally when comfrey tea is mentioned on a gardening programme on TV the next thing they say is that it smells awful. I think the difference is that i make the tea in what is in effect a large funnel, so any liquid produced drains out straight away. This means that some sort of aerobic decomposition is going on, whose bacteria do not make a smell. I am now in the habit of putting seeding weeds into a barrel of water to rot the seeds before they go on the compost heap. This barrel ferments with anerobic bacteria to produce the worst smell imaginable. This goes to show that it is the method you use which determines if there is a smell produced or not, and not what material is being decomposed. As you comment i do cover the comfrey with a thick plastic sheet which has an old steel mesh panel above which fits inside the container. The whole is weighted with a large stone. I think this pressure and the enclosed atmosphere is required to make the thing work. I used to use 4" plastic drain pipes stood vertically with a two litre pop bottle full of water in the top as a weight and a 6" nail in the bottom. This works OK for smaller amouts of comfrey, but is quite difficult to fill. There are more photo,s on the old site. Glenn
I have a single plant, when will I be able to cut the leaves or cut up the roots to make more plants? I have 100' x 200'(about31X 62 meters) space to let it grow in. So it has room to grow & if it ever gets to the edge, a lawn mower & shovel will keep it at bay.
Hi Joel, I highly recommend that you read Glenn's link on comfrey: You will need a dedicated site to plant it. Mine grows 3 feet in diameter and the same height. Get Bocking 14, a sterile hybrid and never ever cut the roots. Scraps from root division which fall on the ground grow new plants. They love water and hate convulus like morning glory and bindweed just as much as they hate quack grass (Agropyron repens)....the name has changed. You could get way more than the four cuttings that I got up here in the high country (May through September). I put some leaves on my garlic and could definitely see a size difference. Please read Glenn's link, I has much more than comfrey info. Mike DeLate, Tetonia ID,USA
Hi Jessica, I hope this reaches you, I'm never quite sure about the navigation on KGI. Your data appears to be out of Fertility Gardening by Lawrence D. Hills '81 (I bought a used copy through What a fascinating book, I have already used several of the techniques described within. My next project is making comfrey tea in a plastic garbage can with a spigot in the bottom. Hills mentioned a product named "Odorcure" which I have been meaning to ask Glenn about. I plan to store the tea in A & W Root beer bottles which are tinted to stem any degradation of the tea. I'm on my third and final cutting of Bocking 14 comfrey. I'll have to report back on odor but I like Glenn's idea of letting it drip. Glenn's link to is most excellent, Lawrence Hill's is quite the dapper fellow. Mike DeLate, Tetonia ID, USA
Hi Mike Its good to hear from you. I hope you are well, the last time you posted i think you said you had been ill. I,ve not read any of Lawrence Hills' books, so maybe its time i read one. I do more reading in the winter anyway. I must admit that i am still working my way through the last one you suggested 'Teaming with Microbes' so you can see how slow i am. I have not heard of 'Odorcure' but i don,t find odour a problem. Today i stuck my nose into one of my 5 gallon plastic storage bottles full of comfrey concentrate, and i can honestly say it was nearly odourless. Mind you my nose does not work perfectly. One thing i did get one year was some nasty looking larvae living in the dripping bucket. I don't know what they were but they were happy in there. Glenn
Hi Glenn, Good to hear from you in return. I am in much better health trying to make up for lost time int he garden before the pretty white stuff falls. I "Googled" odurcure and got a couple of New Zealand sites, its primary use was for septic tank odors. I recall mention of fly larvae (maggots) but I'm not sure if it was in nettle or comfrey tea. It seems like they mentioned gauze or screen over the container to exclude the flies. I highly recommend Lawrence D. Hills Fertility Gardening, I find something new every time I refresh my memory about his techniques. It has a wealth of info on older and much more sensible garden applications. I also had to put "Teaming with Microbes" up until this coming winter. There is so much to digest that I wanted to sleep on it for a few months. I just finished my comfrey extractor and can't wait for the tub and tile caulk to cure around the spigot. How much comfrey do you grow to fill 5 gal bottles full? I'm fairly sure that I can get 4 cuttings off my five plants. I'm going to divide one and begin planting it under my windbreak trees. I could have a hundred plants in a couple or three years. With my lettuce failure (due to poor health)I concentrated on infrastructure and easily got 5 years of work done. We have had five frosts and there is a foot to 18" of snow in the high country. So it looks like I will have another month for chores. I save the heavy work like digging for the colder months and hardly break a sweat. Be well My friend, Mike DeLate, Tetonia ID, USA
Hi Mike I have comfrey plants growing along two lower edges of my allotment, which would be about 100 feet in length with a plant every 12" to 18". That would be about 75 to 100 plants. I imagine it like like a seive trapping underground leaching of the nutrients. I think it is worth pointing out to people that comfrey in the wrong place could become a problem weed. So it is worth finding the sterile type [Bocking 14] and also giving thought to the placing of the plants. The roots are very long, fleshy and brittle so digging up a plant that is in the wrong place is not easy. The fleshy roots break when you dig and each piece of root left in the ground will produce a new plant. I started with five tiny pieces of root [1" long] about 10 to 15 years ago and by taking root cuttings have increased to the number of plants i have now. I get three to four cuttings a year as well. Good Luck. Glenn
Hi Glenn, Page 75 in Hill's Fertility Gardening said & I quote. "The object of covering the butt and blocking the pipe hole in the lid is to keep out drone flies, which will lay eggs that develop into very unpleasant looking larvae known as 'rat-tailed maggots', and also mosquitoes.....'. I believe the reason they got odors is that they added water. Odorcure may have been used for chamber pots. I completely filled a plastic 20 gal. trash can with comfrey from my 4 1/2 plants. It would have been to much had I not trimmed the stems, which I used as a compost activator. Do you add the stems and do you wilt the comfrey first? I put a small screen from an old faucet on the inside of the spigot, I hope it doesn't plug up. I'm going to start closing the garden down for winter tomorrow. I still have a few wiring, construction chores, winter rye to plant and a new spigot line to dig. I will then be officially ready for winter and garden research. Mike DeLate Tetonia, ID USA

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