Comfrey fertilizer is considered a powerhouse in the permaculture garden. Here are seven comfrey uses for building healthy soil and growing healthy crops.
This page may contain affiliate links. Please read my disclosure for more info.
Comfrey: The Permaculture Star
If permaculture design had a poster child, it would be comfrey! It is a multi-functional, prolific, and low-maintenance herb—all the things we look for when selecting plants for the permaculture garden.
Among comfrey’s many attributes are its beautiful purple flowers that attract pollinators and other beneficial insects. Meanwhile, the large leaves shade the soil and provide habitat for beneficial insects.
It is also one of the most potent and effective medicinal herbs. Learn more about comfrey’s medicinal benefits in my article about how to make herbal salve.
What’s more, comfrey is known for enriching soil and accelerating soil-building.
7 Comfrey Uses in the Garden
If you’re wondering how to use comfrey in the garden, here are seven ways to take advantage of its ability to enrich and condition the soil.
1: Activate Compost
This is the most versatile of all the comfrey uses I mention in this article. Activating a compost pile allows you to more quickly make a rich and balanced soil amendment, which can then be used anywhere organic matter is needed.
In fact, because grass clippings and other compost ingredients can be contaminated with herbicides (even if you don’t spray), this prolific green matter is important for home composters.
Comfrey cuttings make an excellent bioactivator in the compost bin. If you have a large amount of dried brown material—such as fall leaves—layering it with comfrey cuttings is an efficient way to balance out the carbon-to-nitrogen ratio and jumpstart decomposition.
To give the compost pile an immediate kick into high gear, collect comfrey leaves and crush them. I like to use garden scissors to quickly cut through the leaves roughly. Add a small amount of water and stir/crush for a minute or two.
Add more water to liquefy, then pour the entire solution onto the compost pile. This quick little extra step is the equivalent of chewing food. The pre-digestion helps beneficial microorganisms of the compost pile (like those of our stomachs) work faster.
The finished compost will have a higher nutrient content with the addition of comfrey fertilizer.
Would you like to grow food in your front yard without sacrificing curb appeal? Check out my mini guide, The Permaculture Inspired Edible Landscape.
2: Comfrey Green Manure
Green manure is an alternative to—or supplement to—animal manures as a soil amendment. Green manure plants are simply cut back and turned into the soil.
For those on city lots who may not have easy access to livestock manures, green manures are the way to go. In fact, out of all the comfrey uses in the garden, this is by far the simplest.
Manure sources are rated for their NPK values (Nitrogen-Phosphorus-Potassium) since these are the primary nutrients that plants need for healthy growth.
Compared to animal manures, comfrey values of NPK are relatively low. However, its nutrients are more immediately bioavailable to plants. Whereas animal manures can burn plants if added during the growing season, comfrey green manure can be applied at any time.
When using comfrey as a green manure, add chopped comfrey to garden soil in the fall. Gently mix it into the top layers of the soil using a digging fork. By spring, it will have decomposed and enriched the soil.
Alternatively, comfrey manure can be added in the early spring—at least two weeks before planting. To jumpstart the decomposition of the comfrey manure at this late date, try the quick method explained above under Activate Compost.
Note: Comfrey plants may not emerge from their winter slumber until late March/early April depending on your location, so there may not be comfrey leaves to chop and spread before the growing season gets underway.
To counteract this potential problem, see the next step!
3: Powdered Comfrey in the Garden (The Best-Kept Secret of all the Comfrey Uses!)
Having dried comfrey on hand is a habit that I’ve grown accustomed to. Dried and powdered (root or leaf) comfrey can also be used to build and fertilize garden soil.
Make your own by air drying comfrey or by using a dehydrator (here’s mine) at 95 degrees until crisp. Remove the dried leaves from the stems and use a blender or coffee grinder to make a leaf powder. Store in an air-tight container.
Simply mix powdered comfrey into the soil with a digging fork, about two weeks before planting. Remember that powdered comfrey is more concentrated than fresh leaves, so a little goes a long way. A sprinkle along each row should be plenty.
Powdered comfrey fertilizer can be used in the late winter/early spring garden before comfrey plants have woken up and produced leaves. The powder also decomposes more readily than fresh leaves, which is better for the spring garden.
I use the dried comfrey leaves to make a healing salve for cuts, scrapes, bites, bruises, sore joints, and all manner of external ailments. Sometimes I get busy, though, and purchase this farm-grown and handmade comfrey salve. Either way, I always keep some on hand!
Would you like to learn more about using herbs to improve the biodiversity of your garden, reduce maintenance, and increase yield?
You’ll find loads of information just like this in my award-winning book, The Suburban Micro-Farm.
4: Condition Soil on Future Perennial Garden Sites
Comfrey’s roots break up heavy clay and creating channels for aeration and better water absorption, similar to dandelion roots.
Over time, its decomposing leaves and roots enrich and condition the soil. This dual action of decomposing leaves and roots can help improve marginal land.
If you have an area with compacted soil where you plan to grow edible perennials in the future (such as a food forest), plant the area with soil-busters like comfrey to break up the hardpan and loosen and condition the soil in preparation.
Here are a few more of my favorite soil-busting plants.
Since comfrey prefers rich soil, give it a head start in poor soil by adding a shovel of compost.
5: Boost Seedlings When Transplanting
Young perennials (fruit trees, berry bushes, asparagus, herbs, etc.) and fruiting vegetable seedlings (tomatoes, peppers, cucumbers, squash, etc.) will enjoy a nutritional jumpstart from comfrey.
At the time of planting, bury a few comfrey leaves underneath each planting spot. As the comfrey leaves decompose, they will provide a nutrient boost for young plants.
6: Comfrey Tea Fertilizer
Compost tea is an excellent way to provide an immediate nutrient boost to established plants. It is made by steeping fresh plant matter in water for a certain amount of time, straining the liquid, and using it to water stressed plants for a mid-season boost.
Comfrey compost tea can help overall growth, and encourage better flowering as well as more vigorous growth in perennials and mature fruiting vegetable plants (i.e., tomatoes, peppers, potatoes, cucumbers). Do not use comfrey compost tea on young plants.
Out of all the comfrey uses list here, this method takes a bit of extra time and planning. However, its effectiveness is noticeable very soon after application. There are several ways to make this fertilizer.
- My favorite is an aerated comfrey tea, which includes beneficial, “living” organisms along with the nutrients. I use a compost tea brewer kit to make this, which takes about two days.
If you don’t have a bubbler kit to make the aerated version, there are other ways to make this fertilizer.
- To make a strong comfrey tea: Fill any size container halfway with fresh comfrey cuttings. Fill with water, cover, and steep for 3-6 weeks. Warning: This will smell really bad! Strain off the liquid and dilute by half. Or if using a hose end sprayer, no need to pre-dilute.
- To make a weaker (less smelly) comfrey tea: Add one gallon of water for every quart of fresh comfrey cuttings. Let sit for three days, stirring daily, then strain and use full strength.
- For a quicker comfrey tea: Measure one quart of water for every ounce of dried comfrey. Boil the water and pour over the dried comfrey. Let it cool for 5 minutes, then cover and steep for 4 hours. Strain, then dilute with 1 gallon of water unless using the hose end sprayer.
Be sure to compost the leftover plant solids.
7: Comfrey Mulch (My favorite of all the comfrey uses!)
Mulching is a great way to protect soil and prevent erosion.
Mulching with comfrey—also called chop-and-drop—can help to retain moisture and protect beneficial soil organisms. Comfrey mulch decomposes quickly, which activates soil microbes.
I grow comfrey underneath my perennial edibles, such as fruit trees. I chop and drop the comfrey to feed the fruit trees, or I can pick up the cuttings and take them to the vegetable garden.
Read more about growing comfrey under fruit trees in my post The Cherry Tree Guild.
Here’s the kind of comfrey that I buy for planting. Also see: How to Build a Fruit Tree Guild
For more information about this herb, see my article about growing comfrey.
As you can see, there are many comfrey uses in the permaculture garden. By reducing costs on imported soil amendments, creating healthier plants, and improving yields, it provides a lot of value to gardeners.
How have you used comfrey in your garden?
Best explanation of comfrey’s benefits I’ve read. My first plan of action is to rescue the comfrey plants I have from marauding deer and improper placement. After recently pricing organic fertilizers, I’m highly motivated to implement your suggestions. The plants and the wallet both get a boost!! 🙂 Thanks Amy!
Thank you for your kind words–I’m glad this information is useful for you. Those darn deer 🙂
I have a new container garden(24 containers) and want to plant herbs and flowers around them that will attract beneficial insects to that area. Have a list of things to plant but missed the comfrey, glad to read about all the benefits of growing it, adding it to the list!
Comfrey would be a great herb/flower to add to your list for beneficial insects. The only challenge is that because comfrey has deep roots, eventually it will be too constricted by a pot and lose its luster. I wonder if you have a spot in the ground near your pots to plant it?
I tried growing comfrey in pots (really just starting out the root cuttings but let them go too long… oops) and they didn’t really grow more than a couple of leaves before they just stopped growing. I finally got around to putting them in the ground and HOLY COW! They got huge seemingly overnight.
Awesome! Comfrey is very clear about what it likes LOL 🙂
This is a great article – I grow comfrey for it’s medicinal benefits, and as feed for my meat rabbits. I knew it could also be used as mulch, added to compost, and made into fertilizer tea, your suggestions make me feel less overwhelmed.
Thanks, Michelle! It’s nice to know when something can be used as a mulch–for example–but it’s even better to know how to do it 🙂 It sounds like you’re already doing great things with your comfrey!
Thanks for this post. I was having a hard time finding info on using dried comfrey, which is what I have. I will refer my husband back to your site when we plan our next garden!
I will look forward to hearing how it works for you 🙂
Judith Janes says
I used comfrey root when my husband was building a cedar-shingled entryway onto the front of our house back in the early 1980s. He banged his shin into a stack of cedar shingles and the toxins in the cedar caused an infection that would not heal. Neo-sporin wouldn’t touch it. I got out the herb book and discovered that comfrey root might cure it. I bought dried comfrey root at the health food store, simmered them covered with water until they were very mucilege-y and made a poultice, which I applied to his leg. I could not believe how rapidly his injured leg healed! Planted my own comfrey plant in our yard and haven’t been without it growing nearby wherever I moved since then. I’m a believer!
Wow, that is quite the testimony! Thanks so much for sharing 🙂
Lisa Gehrig says
I used a poltice on a dogs leg with a large gash on it. It healed amazingly well. Not sure why they call it “Bone Knit” but it helps healing. I grow the bocking 14 also. I’m a Fan!
I too have used comfrey this way. I make small bandages by wrapping the dried leaf with an open weave gauze. This worked so fast on a deep wound made by my sharp hatchet while camping. Overnight the skin closed up and in no time there was hardly a scar left.
in addition to my gardens, i grow comfrey in out of the way places where nothing much wants to grow or needs to grow – behind the garage, in the small space between the bulkhead and the house, etc. then i harvest several times per season and just throw it onto the rest of the mulch on my year-round mulched beds, Ruth Stout style. i love comfrey!
This idea makes me happy 🙂
Jeanne Marie says
Thank you for all the information you put out there,& making it fun!!!
Yay! I’m glad you’re enjoying it 🙂
Enid Adams says
If comfrey is so good at extracting nutrients from the soil, does it leave the soil where it has grown depleted of nutrients? As beginning gardeners, we planted it with other herbs in a fairly small space, not understanding how large it would loom over it’s neighbors. Now I would plant it on the verges to help break up heavy clay where beds might need to be expanded. Or near the compost pile for reminder to use it.
Excellent question! All plants have a certain life span, and comfrey is no different. The plant depends on extracting nutrients from the ground for its survival, so at some point the soil may become depleted, and comfrey will gradually diminish in vigor. But I wouldn’t expect this to happen in my lifetime except in very poor soil. I’ve also observed comfrey dying out more quickly in full sun/hot/dry areas. If it has access to a little bit of shade and/or moisture, it should last a long time. It is good at extracting minuscule amounts of nutrients.
Keep in mind that if you don’t harvest the comfrey and it dies back on its own, it will re-fertilize its own soil. I am always careful to leave some of my comfrey cuttings for the comfrey plants themselves 🙂
I was initially surprised by the size of comfrey, too 🙂 I love your idea of planting it near the compost pile!
George Bouthillier says
I planted comfrey over 50 years ago on our side border of our property near the garden and at the back part of our property is a swamp!This comfrey that I plant only a few now today is going very strong and healthy and has seeded itself all over our property here and there I guess the birds or other animals must have at the seed and then pooped them out here and there all over the place!Plus iI dug some up once in awhile and threw it in the side of the swamp where skunk cabbage was growinf it took over there and drove the skunk cabbage away!Plus I did it on purpose cause it attracts tons of honey bees and they continue to pollinate my garded and other crops and the bees have set up there homes all over my property which was my plan aswell!I use it as a mulch in garden and tear up leaves and put then in planting holes and I always have fabulous crops!
Steven Gaylord says
Thanks for the tip. I’m putting it into action.
Mustafa Taner says
What is the exact Latin (international) name of the plant ?
Melissa Keyser says
“If permaculture had a poster child, it would be comfrey” HA!
I often say that if organic gardening has a poster child, it would be fava beans. Comfrey works as well. 🙂
Arthur Pearsall says
I live in the subtropics in Australia. I planted comfrey under my citrus trees, following the practise of my sister in New Zealand. When the comfrey grew too dominant under the young trees, I would cut it and use it as much under other trees or on garden beds. I have used comfrey as a herbal medicinal resource for over 45 years now. But only in the last 10 on.my new property in the subtropics have I found a need for caution. It seeds so effectively here, that I now have comfrey as a dominant plant all over the garden. Lots of Mulch though, but I remove the flowers first.
Yes, it seems that removing the flowers regularly is a good habit to get into with the true comfrey 🙂
I’ve discovered a way to get the benefit of the comfrey tea without the awful smell. I simply used an aquarium air pump to bubble air into the bucket while steeping the leaves. You get all the goodness without the stench.
Hi, I have a comfrey plant that we planted about 15 years ago if not more. At first it grew quite slowly, but later on started growing quite figurously, it dies back every winter because of frost, but comes back with a vengence. I have tried taking some of the plant out, but it just keep growing back, taking up more and more space.
Truly don’t think it can die or deplete the ground.
Thanks for a great post, know what I am doing with ALL the plants I have.
Mike B says
We have used comfrey for many years. First in the UK and now here in France. To avoid having it spread all over your property make sure you use the Bocking 14 variety. This was produced to create a plant that can be managed in any size garden but also comes back each year to produce its excellent leaves. Our dozen plants have served us well for over 13 years and two weeks ago there was no sign of it, now we have large leaves and can think of starting to harvest them quite soon. That is early April.
Wear gloves and cover your arms when handling the leaves as the tiny needles on the leaves and stalks can cause irritation.
The advice on here is very good but its a good idea to research comfrey’s use generally so you get to know its advantages but also its limitations.
It is very important to be aware that as a medicinal plant it has its dangers. In fact I understand that some States in the USA have prohibited it as a herbal additive or have sent out warnings about its use. Please do your research thoroughly before using it medicinally.
I found that if one puts a wire mesh around the plant it won’t grow further. Same with putting down pieces of plywood all around it. The large plant next to our compost was wonderful and stayed within its bounds.
Where did you find the NPK ratios for comfrey?
Great question. The NPK numbers are quoted in this article, which refers to a research study in British Columbia. I wasn’t able to track down that study, unfortunately, but this presentation by Cornell University shares similar findings.
To avoid the smell Place comfrey leaves in an old pillowcase and don’t add water and allow to decay in a container..dilute the thick fluid really well. While not smell free it is less offensive and very concentrated so easier to store for later use.
The bag makes turning the sludge out at the end much easier. I put the sludge on the compost heap before reusing the bag.
I found a less smelly way…just fill a lidded container with comfrey leaves and stalks (crush or chop to speed process, and leave…can use small amount of water to start decomposing process. Very concentrated. Less smelly. Bottled it up and dilutes well to use. Was very effective.
If you have a tap, make sure you have a filter on the inside so you can take off some of the liquid as you go.
I chop the comfrey down two to three times each season to compost. Putting fresh cuttings into soil can result in more comfrey plants and I already have plenty. My chickens and ducks would eat some too. Deer as well were eating comfrey in the Fall.
Nice article. Seems like it would be important to caution readers of comfrey’s roots–that if you try to till an area of it, it will propagate profusely. It takes very little of the root to begin a new plant. That is good news if you want a lot of plants, but not so good if you don’t want your whole garden overrun by comfrey.
Having grown comfrey for years in the city and rurally, I used to cut and dry the leaves, putting them into a green bag and each year I learned of a friend or neighbour who’d injured themselves. I gave them the comfrey with instructions to make a poultice of warm oil, laid over the dried leaves. Comfrey’s other name (one of many) is knitbone and it is a great healer. I’ve had it as a tea plain or mixed with other herbs too. It has so many healing properties for the digestive tract as well.
I have some large comfrey plants at the back of my garage that a friend gave me a start of…. but I never knew what to do with it. When you harvest it several Tim’s in the growing season, how do you know when it’s time to cut it back? And do you cut all of the leaves back to the ground? How close to the ground? Thanks for the help?
It’s not really an exact science. 🙂 The leaves get huge, so you’ll know when they’re ready, but you can cut them back at any time. I give them a good clean cut at the base.
Your book was my first introduction into permaculture principles, and I loved it–thank you!
Here’s where I’m at: I’ve brewed up several 5 gallon buckets of comfrey tea to use to revitalize my back yard of mostly dead grass. The soil has lots of clay, and is highly compacted. It has been covered by thick layers of newspaper & topped with 4-6 inches of hay/straw for the past 4 months, trying to smother the old weeds and grass. I would eventually like to plant up that area with swaths of buckwheat and crimson clover to attract bees and beneficial critters, as well as to enrich the soil.
My question is this:. Should I pull back all the “sheet compost”, spray the ground with the tea using a hose end sprayer, then cover it back up? Or should I leave it off after that?
Another question: With impending rain forecasted, should I spray the comfrey tea before or after the rain? (Keeping in mind that I live in Southern California, where a “rain storm” could mean a spattering of showers throughout the day, a healthy amount of steady rain, or just some spitting rain clouds passing by!)
And finally, how long do I wait after applying the comfrey tea before broadcasting the seeds?
I sure thank you for taking the time to read through this!
I would spray compost tea on top of the sheet mulch a week or so prior to planting or sowing, but not before a big rain, which would wash it away. If it’s aerated tea, you can use it undiluted, if it’s not aerated, dilute at a ratio of 10:1.
Can you comment on the dangers of handling comfrey? I have read that the PA content can be absorbed by the skin, and can cause cancer and liver damage. Does this harmful agent leech into the soil and into the plants it is nourishing?
Toxicity is not known, to my knowledge, at the level of handling, and any phytochemicals readily biodegrade in the soil. In addition, plenty of skincare products, store bought and homemade, include comfrey.
Bonnie French says
The only danger I have found is from touching the stiff hair in the leaves and stems, it gives me a bad rash like stinging nettles. So I wear long rose trimming gloves.
Bonnie French says
How do you kill established comfrey plants when you want to plant something else in that area? I have about one quarter of an acre of comfrey, which is more than I can keep cut back and it kills everything else planted in the area.
Sounds like you have True Comfrey growing on your site, which spreads by seed. To prevent it from spreading more, simply cut it back or mow it about once a month to keep the flowers from dispersing seeds. It’s difficult to get rid of once it has spread, which is why I promote growing Russian comfrey (aka Bocking 14), which has sterile seed and cannot spread in this manner.
Is the Symphytum uplandicum that you recommend also medicinal like the Symphytum officinale, that spreads its seeds
The two are assumed to have similar medicinal properties, although I’m not aware of any scientific studies that confirm this.
After reading your article about fruit tree guilds I bought a few comfrey plants to put under the fruit trees. We live in Hawaii so we have comfrey growing actively all year long which means that I can do the chop and drop every few weeks during the year. When we first moved here we saw only a few bees but now we have many honey bees thanks to the constantly flowering comfrey! We’re ready to plant our first two raised beds in vegies and will try chopping a few comfrey leaves to put in the bottoms of the planting holes.
Thanks for all the good tips!
After reading all the benefits of comfrey, the person who lets me tend the garden planted some in the raised beds. Once it completely took over its designated area and started spreading into the edible veggies, I tried to move it, but even the smallest piece of root sprouts back. Any comments on this aspect of comfrey?
Hi Jeff—This brings to mind the phrase, “Right plant, right place.” Comfrey is not a plant for garden beds that are cultivated regularly. You don’t want to disturb its roots, which happily grow into new plants if nicked or cut. Rather, grow comfrey in perennial beds, the soil of which isn’t disturbed regularly for planting or harvesting.
Secondly, a new phrase comes to mind, something like, “Right variety, right plant.” True comfrey sows seeds when its flowers die back on their own, which happily turn into new volunteer seedlings. Instead, I plant—and recommend—Russian comfrey, which is a hybrid variety with sterile seed.
I’ve grown both varieties and have had success with both. My 50 or so plants of true comfrey never spread a single volunteer because I chopped them back so often (before they set seed) to use in the many ways that I’ve named in this article. However, I wonder how it’s treating the new owners of that home?
I love reading your blog. We moved to a different state for our declining years to be close to our daughters’ families. This HOA senior community has tiny yards with more rules than the Law of Moses. But…I was determined to have a permaculture food forest even in this setting. I brought my comfrey roots with me and planted them between 12 dwarf fruit trees that I’ve planted in the beds along the (south) side and (west) front of the little house and pruned according to Ann Ralph’s Grow a Little Fruit Tree book. In this strip guild, I also planted asparagus, raspberries, strawberries, horseradish, bush beans, various herbs, and beneficial insect-attracting flowers. Along the north side, I planted medicinal herbs and asparagus; this gives me two different harvest seasons for the asparagus. There is just enough room behind the privacy fence on the south grapes, artichokes, and four 4×8 veg beds. Where there’s a will, there’s a way.
I planted true comfrey years ago and it has spread to most of an acre. Any suggestions on organic ways to get rid of it? I am now propagating a patch of the Bocking-14 variety to replace it.
When you plant true comfrey, it’s there to stay. If it were me, I’d mow it continuously so that it can’t produce leaves or sow seeds. This may eventually exhaust the roots. Alternatively, you have an ideal setup for a permaculture food forest! 🙂
Just an unqualified suggestion. I live in east Florida and have no experience with comfrey. I am reading questions about removing established plants. I was able to eliminate a stand of bamboo by cutting it short and covering with heavy black plastic sheet. Between the loss of light and the extremely high heat generated under the sheet, the bamboo died off after several months. I would expect comfrey would be unable to survive such conditions either.
Dustin Bryant says
Hello, can you use dried comfrey roots and boil a tea and use it to establish and brand new true comfrey root in my garden to expedite its growth?
Any compost tea applications should be applied to established plants only.
Dustin Bryant says
Hello, if you make an aerated comfrey tea after 2 day brewing, do you have to dilute it? If so, what would be to the correct solution per gallon? Thank You
I have heard a story that comfrey roots alkalizes the soil around it causing plants needing acidic soil (like blueberries) to die. I’ve been researching but can find no definitive answer to the issue raised in the story.
What is your experience?