planting comfrey in front yard

here's my situation:  I'm going to buy a small house in the suburbs of the portland region, on hopefully 1/2 acre or more, if i can find it.   No Bleepin HOAS!, that's for sure).  I want to make all my own compost but I"m going to need a lot of biomass to do that.


Since food production is mostly in the backyard, i was thinking of planting comfrey in the front yard - the 10 or 20 feet closest to the street since that area gets hit with a little bit of the street pollution.  but, i can't move into the house for the first few years, so we'll have renters.  I'd like to plant about 500 cuttings or so at 2 ft spacing that would produce about 10K lbs of biomass per year.  Would comfrey be fairly low maintenance in the first few years?  Will it become too unsightly without regular pruning?   how high is it gonna get and will it be too much for the suburbs?

After about 1 to 4 years, we'll be moving in and I'll be able to harvest regularly.

i understand comfrey will always be whereever i plant it.
anything else to consider?

I have four comfrey plants about a foot high in my front yard.  Mine are small, in a waste patch of grass.

However, they can supposedly get this big:
source
I mow mine once a year, other than that I personally do nothing with them.

A couple things to consider:
- be sure to get Bocking 4 or 14, which are sterile.  If you will want more, trust me, you can divide the roots, and meanwhile you won’t be tormenting the neighbors with seed-spread volunteers.
- I don’t know how comfrey acts in the PNW; maybe someone can chime in? Here in 7b comfrey dies to the ground in winter.  A whole front yard of flat black leaf remains sounds… unattractive.  Maybe it could be interplanted with something evergreen?
- Speaking of interplanting, my comfrey under trees does almost as well as in the sun, so if I were planting more I’d fill in the spaces under fruit trees to keep grass down.  Not too close, though; you don’t want to provide a rodent home complete with bark to eat, and also I suspect comfrey doesn’t play well with some shrubs.
- Finally, after the first year you can whack it down 2 or 3 times a year and throw the leaves into the compost.  Be sure to agree with your renters that you have occasional access for that and that a compost pile is ok.


Sounds like a fun idea!

Replying to my own comment:

- yes, my comfrey does grow as large as in Rachel’s picture.  Fear the comfrey!
- also, bees love the flowers, which is great, but I have to whack it down early morning or late evening to avoid their wrath.
- which also suggests checking that renters aren’t allergic!
- and looking back at your original post, 2 feet apart is too close.  I’d say 4 feet apart, mulch in between, and maaaybe you can fit something in between that will have time to get tall before the comfrey overwhelms it.

My comfrey patch quickly grows 3-5' tall, and I prune it daily to feed the piggies.
Expect massive self-propagation if you plant 40 plants this year, you will have 60 in just a few years.
One year the pigs got into the fenced-off area where the comfrey grows.
They were only in there a few hours but managed to chow down all the above-ground plants.
They did not have enough time to go root hunting.
Within a few pig-free weeks, all plants were growing like crazy again.
I expect that even with time to root, they would not have wiped out the plant, they are extremely prolific.

EDIT)  They are under several feet of snow here  in zone 6A

I have planted literally hundreds of them.  I have a particularly fertile area around an apple tree that I mulched very heavily with wood chips.  I have had comfrey grow to 7' to 8' feet near the trunk of the tree where the low hanging branches support its growth.  In areas where nothing is touching them, the ones I have planted in good soil will get higher than my head before tipping over from their own weight.  In less productive soil, they will tip over at 3' or 4'.  

If you plant them in your front yard, they will get to the soil dependent height they are going to reach, and then the stalks will fall outward creating a big daisy-shape on the yard.  If they are 2' they will fall against each other and tip over to varying degrees.  If you can spare the room in the backyard, I would grow most of them in the backyard, maybe putting a couple staggered rows in the front yard at the 4' distance mentioned earlier.  I love, love , love comfrey and have been raising it for many years.  I wouldn't want my front yard covered in it, but that would be very much a personal preference.  In the suburbs, I think you will probably get some unkind feedback.  In addition to that, having it in the backyard would make it much closer to where it is needed, and moving 10k lbs of biomass would necessitate it being close to where I would be using it, at least for me.

I don't know if I would call it "low maintenance" for a few years.  Comfrey in good conditions (for it) grows like crazy.  If you can cut it down to the ground a few times a year, you can keep it looking fairly neat, but if you do nothing, it will be organized chaos :)  I like that, some people, probably most, do not.

This is unrelated, but is one of my "pro tips" for comfrey growing.  When it gets to the point of tipping over, it will probably be flowering.  If you don't need it immediately and want the bees to continue to be able to use it, just step on the middle of the plant, breaking the stalks down to the ground.  They will continue to grow and flower, but the new growth will start from the middle again and it's like growing a new comfrey plant in the middle of the old one.  After flowering, you can cut the broken stems and use them, and by then, the middle new growth will be much closer to full size.

Trace Oswald wrote:In less productive soil, they will tip over at 3' or 4'.

I can corroborate that. I bought my comfrey from Trace maybe three years ago and grow it in lousy sandy loam -- 3-4 feet is where mine tip over.

I have been planting comfrey cautiously because of how many people insist it will take over the universe.

I suspect it would interplant with Borage fairly well, and my Borage seems to overwinter with minimal protection in some places. Depending on the winter weather, the Comfrey will put up some leaves.

I think mowing could be messy - it is very easy to chop lower with a hand blade like a hand scythe.

If it goes wrong, sheet mulch would be my first choice of removal. It might take several applications, but in our summer droughts, it is quite possible to kill the stuff... I've done it!

Borage is also a bee magnet. Our pollinators are in trouble. If you're worried about complaints, put up some sort of "Pollinator Garden and Refuge" sign and plant it as a polyculture. I find that most of the bees will totally ignore me if there are flowers they like. They also adore raspberries, and they will bloom twice in my area.

I have comfrey in my front yard, but my front yard was already terraced and planted with other things before I started planting comfrey.
If you get winter dieback, wall to wall comfrey could mean a muddy mess.
They compost well and easily but they do not contribute much bulk.
During summer I can cut it down and lay it around my vegetables and it will kinda disappear into the soil in a week or so.
When dried, they reduce down to very little, much like cooking greens do.
For bulk, consider planting clumps of  non-invasive ornamental grass, maybe with Comfrey around the base.
Ornament grasses are suburbia friendly and should be cut back once a year for plant health.
I have had good luck with alfalfa, but that is all fed to the rabbit.

everything everyone else says - comfrey loves moist so it should do well there but unless you are chopping it down by hand 2-3 times a year it will indeed get 4-5 feet and then fall over and discolor etc... it won't create a meadow like grasses/wildflowers

you may well have a mess and 500 cuttings will yield a LOT of comfrey in 2-3 years .. so def plant other stuff in there

Another thing to remember is that the dead comfrey leaves are supposed to be the best overwintering spots for spiders. So they may be a little dark and drab but ecologically they are amazing! It is also true that they tend to flop over every once in a while when not cut.

I'm in NW Washington. I went a little nuts planting cuttings from my comfrey all along the pasture fence and under many of the fruit trees.  My old girls easily hit 5 feet and spread and collapse and send up new leaves all summer long if I don't harvest some. My goats love it! In the winter, they just kind of wilt down and my geese finish them off but spring brings them back in a frenzy. I have noticed they don't seem to get as big in the shade of the trees but they still do just fine. They shade/smother everything near them so planting something like evergreen shrubs by comfrey may not work so well.

I have 5 scres of clay and agates. Terrible pasture grass. I was thinking of comfrey to aid in adding organic matter and to break up the soil. All the comments here make it seem positive, especially the bee comments. Does it grow in clay without a lot of bother?

I'm in Melbourne Australia, and have comfrey throughout my front and backyard. We are in heavy clay and it grows no problem.
I'd just caution that if you ever dig it up - you'll always leave at least a bit of root behind, which will sprout again. you really don't need much to propagate and spread it. So, don't plant it where you don't want it!
I'm aware that most of you are above the equator, but down here, my species of comfrey grow to about 70cm (i don't know what that is in feet!), and then die down. I can cut it down 3-4 times in Summer alone, no problem, and it will shoot up again. It does die down in Winter, and the spikey leaves can be a little irritating to the skin if you're taking the leaves for compost / moving it for where ever you need. I tend to just chop and drop.

I have planted comfrey at home and at my in-laws place.

At home we have thin soil on well draining chalk. The soil tend to get dry in summer. The comfrey grows, but does not thrive. I do get to cut it typically once per year as mulch but don't get a large enough quantity to use elsewhere. Where it gets crowded by other plants it tends to die out after a year or so. It is far from being a thug under these conditions.

At my in-laws the conditions are very different. They are on low lying flat land with deep silty soil and high year round rainfall. The water table is at most 18 inches below the surface and stays moist even into summer. Under those conditions comfrey is amazing! It grows to 5ft high over a matter of weeks. It protects and nourishes the soil around the fruit trees. It makes huge amounts of biomass for mulching. The trees it is planted around thrive and crop really really well.

I suspect that if I were able to consistently irrigate my comfrey at home that it would do better, but under the conditions I have it is lacklustre.

I'm not s fan of monocultures even in small zones like that.  By using comfrey this way you lose out on a lot of it's strengths and also have a challenging front yard for curb appeal.  But if you took this same approach but added a couple nice looking fruiting shrubs like haskaps, and some smaller fruit trees into the mix perhaps a couple apples, cherries, plums or pears.  Depending on size of the yard you could do a couple pairs of trees.  

So maybe 4 trees, 6 shrubs, comfrey around each planting, paths, and then comfrey or perhaps something else that would be a nice addition in the gaps, you've made your front yard beautiful, productive and the comfrey benefits the fruit trees, helps the soil, produces some mulch, produces biomass for compost.

Forget about removal.  The roots are extremely deep and determined!

Zone 9 here.

Comfrey only does well in the shade here due to the brutality of our summers.
Does well in the woods or under big trees particularly.

Mine never gets tall enough to tip over.
Seems to stay lower and spread.

A few links:

https://smallfarms.cornell.edu/2022/04/new-findings-further-the-study-of-dynamic-accumulators/?

https://www.interdependentweb.com/web/content/does_comfrey_really_improve_soil?

https://www.permaculturenews.org/2019/07/26/all-about-comfrey/

https://veganorganic.net/comfrey-wonder-herb/

https://www.tenthacrefarm.com/what-is-comfrey-and-how-to-grow-it/

https://www.motherearthnews.com/organic-gardening/comfrey-leaves-zmaz74zhol

https://soilandhealth.org/copyrighted-book/russian-comfrey/

https://soilandhealth.org/copyrighted-book/comfrey-report-the-story-of-the-worlds-fastest-protein-builder-and-herbal-healer/

It's true, you could never have enough comfrey, but you may struggle in the future if you plan on planting something else to replace a 5 year mature comfrey patch. One option would be to take a leaf from the school of famed English Gardner 'Monty Don' and create 'rooms' in your garden. Comfrey makes a great hedge. You can use hedges to surround annual plots (making rooms) and then grow cover crops in those plots until you are ready to plant something else in them. A plot of Sudan Grass and tillage radish can create even more biomass than Comfrey in the same area. With good cover cropping strategy, you may not even need as much compost as you think.

I'm just learning about comfrey so a few questions. How does it improve the soil around fruit trees? Is is just leaving the leaves as they die for compost or does it do something else for the soil. My place is mostly woods but I have a garden, some fruit trees and a large grass area that I use for a burn pile as I clear trees and brush. I'm sure I can find some places to plant comfrey that I won't have to worry about it getting out of control. Would like to use some as compost greens, but does it help the fruit trees if I just leave it natural around them?  I'm in zone 7b

Melissa Lanray wrote:
I'm aware that most of you are above the equator, but down here, my species of comfrey grow to about 70cm (i don't know what that is in feet!), and then die down. I can cut it down 3-4 times in Summer alone, no problem, and it will shoot up again. It does die down in Winter, and the spikey leaves can be a little irritating to the skin if you're taking the leaves for compost / moving it for where ever you need. I tend to just chop and drop.

Melissa, that's exactly how comfrey behaves at my place! We get tons (too much) rain here but the comfrey thrives in it and I get the same multiple growths whether I leave it to fall over or feed it to the critters! I don't have clay here, just gravel and sand but it doesn't seem to matter to the comfrey

Dave Bross wrote:Comfrey only does well in the shade here due to the brutality of our summers.

Huh. Weird. Here, full shade kills comfrey. It does kinda okay with 3 hours of sun, and looooves 6. It does fine in most areas of our acre, even with 9 hours of sun. But in one dry spot it 'died' to the ground both winter and our 2 month summer drought. That plant eventually died.

Comfrey's roots are quite deep, so they can reach mineral resources the more shallow rooted plants cannot access.  The leaves provide those resources to the trees and other surface plants, and they thrive on it.

Being so deep, the roots also help break up hard soil (I have heavy clay) so rain can percolate down and other plants have more of a chance at thriving in the loosened soil.

I cut my comfey back several times a summer, for use as mulch/fertilizer, for medicinal use, and to keep the flowers from setting seed.  My plants have rather boring flowers, even en masse, so while bees love them, don't expect a glorious show.

When they die back in the winter, they look black and unappealing.  Take the opportunity to cut them way back and compost the leaves, and the stumps that remain won't look so bad.

I think the suggestions to interplant comfrey with some fruit trees are a great idea.  If you're not ready to take on the maintenance of the fruit trees yet (Grow a Little Fruit Tree is a fantastic resource)( I can't remember the author), plan out where you'll want them, and don't plant comfrey too near those spots.  

The way comfrey grows and spreads, I really think you'll want to plant less than half of what you're thinking. It's great around trees (not too close), and my raspberries love it, but smaller plants will probably be overtaken by it.

Joe Klerekoper wrote:I'm just learning about comfrey so a few questions. How does it improve the soil around fruit trees? Is is just leaving the leaves as they die for compost or does it do something else for the soil. My place is mostly woods but I have a garden, some fruit trees and a large grass area that I use for a burn pile as I clear trees and brush. I'm sure I can find some places to plant comfrey that I won't have to worry about it getting out of control. Would like to use some as compost greens, but does it help the fruit trees if I just leave it natural around them?  I'm in zone 7b

What I know about comfrey.  It does do something beyond providing mass for decomposition.  As a “bioaccumulator” it absorbs particular minerals out of the soil, which provides those minerals to surrounding plants as they decompose.

Comfrey has mucilagenous roots.  In moist conditions, if a root is wounded there is an exudate which promotes healing, as medicine for people and livestock and for its own roots.

Comfrey has allantoin, I don’t know if it’s in leaves and roots or concentrated in just one or the other.

Worms have grown in abundance next to comfrey roots in my gardens, promoting soil aggregates.  (The highly desirable cottage cheese appearance of soil, which indicates that the soil will allow water to soak in).

I think if you mow or cut the comfrey it will be more beneficial for soil development and adjacent trees.  This is because cutting back stimulates the plant to provide root exudates for soil bacteria and fungi.  The fungi carry nutrients to the roots of the comfrey plants.  The bacteria produce ?is it called glomulin? a gluey substance which also contributes to the production of soil aggregates.  But if you don’t have time to cut it down, don’t worry!

Comfrey promotes the soil food web.

Comfrey does fabulous things for the soil!

As for whether it’s good right up next to trees, I cannot say.  Someone posted above problems with creating habitat for rodents that eat bark.

Pascal, when you plant your Comfrey, put some manure into each planting hole. I used 3-4 horse nuggets per hole and the Comfrey came up with a vengeance! At 2' spacing, it forms a nice border along walkways. You can prune it back during the growing season and use the leaves as a mulch around garden plants and flowers. Comfrey is tough. You can even use chicken manure around it and it won't burn it.

I live with blueberries, black spruce, peat and red maples so acid soil and lots of clay. I sowed common comfrey and kept a close watch afraid that it would spread. It does self-seed but it's not invasive at all here. That would be 7-8 years ago and most died. They gave very little leaves but lots of flowers and attracted lots of bumblebees which I like. I've seen claims that roots can get 8-10' deep, not for me. I've never seen any root deeper than 3' here, not just comfrey, everything.  

Next I tried bocking 4. Much better leaves and much larger plants but all the flowers are brown inside and bees don't like them. That was a big disappointment. I don't know if it's just my plants or if it's characteristic of bocking 4. I can cut it all the way down once and it will come back before the frost put things to sleep. But it's ugly then, and takes much longer than two weeks to grow pretty again. So I would not do this in front of my house if I want to keep things pretty. My chickens don't care at all for the leaves.

I plan on trying bocking 14 this year see what it does.

All I do is get a plant, dig a hole put it in, water and wish it luck. Maybe I'll water again but maybe not so yeah it's a though plant.

Thelka wrote:Comfrey has allantoin, I don't know if it's in leaves and roots or concentrated in just one or the other.

Allentoin is a cell proliferant. Herbalist speak for it make new cells grow very well, promoting fast healing. It is in both leaves and roots, but is more concentrated in the roots.

pascal billford wrote:here's my situation:   I want to make all my own compost but I"m going to need a lot of biomass to do that.      
I'd like to plant about 500 cuttings or so at 2 ft spacing that would produce about 10K lbs of biomass per year.  Would comfrey be fairly low maintenance in the first few years?
anything else to consider?

Well, 500 cuttings will give you a LOT of bio-mass, however, when that composts down you won't have nearly as much as you would think coming from those huge plants. So that 10 K lbs that you are expecting will be a fairly small pile of compost. And WHERE is your compost pile going to exist? It will be huge with cuttings (in your operation you need to cut and grow, cut and grow, all summer long) that eventually will compost, but not as fast as you think either.

I have one plant that looks as large as the one in the photo. I grow it for the bees mostly, but I want to see if I can make a tea using young leaves. I do know that Comfrey is great at stopping blood flow from wounds.