Common comfrey - just how invasive is it?

I just bought a pack of common comfrey seeds. I haven’t planted them yet. I know most people get Russian comfrey or Bocking 14 but I figured it would be okay. Besides, I wanted a lot of it asap.

I’m in the rainy Puget Sound though, so I’m afraid it will grow too well. I’m curious if anyone here has experience with it? Will I be releasing a wonderful plague upon myself and neighbors if I plant this? How does it compare to say foxglove?

Hi there, I'm a landscaper in zone 5b Quebec. My client planted some years before I started working there. In the years since working there I see this white flowered comfrey growing in the ditches and forest surrounding their property.. I'd say too invasive! I dig it out every year and I don't think I am achieving anything lol.

Burn it immediately! There are many different kinds of comfrey, i grow about five. Most are well behaved, none don't make seeds, and most don't creep up agressively. I've got one that is agressively creeping through the roots, and i love it, but it takes up time keeping it where i want it.
I've read of poor bastards who talked about having spread an impossible to contain comfrey all over the garden which does the two, creep quickly and pop up all over the place and the neighborhood. Birds love to spread it too! Everybody knew it was his fault as well.
Nobody should sell the seeds without warning.
ps Ken, this white one you talk about i call well behaved, there are worse ones, and Tyler might have bought one that spreads by seeds on top!

I've lived two places with non-sterile comfrey present, both on vancouver island.

On a generally heavily shaded property with generally poor soil, it has been able to spread only quite minimally. No big deal at all.. so far..

On a farm with the best rich black bottomland soil I have seen, and lots of sun, it was REALLY invasive, everything it is reputed to be and then some.

I will never bring non-sterile comfrey onto my property, and will go to great lengths to kill it if it should appear somehow.

I grow it. I also have two or three other types of comfrey that only spread by roots and divisions.

I try to germinate the seeds in pots and it is difficult.  I do notice an occasional new plant near the main one but nothing I'm worried about.  I think it would be fairly easy to keep cut back so it never goes to seed.  The seeds only seem to germinate where they are in contact with soil rather than mulch.

I think this must be like so many plants that are considered 'invasive' in some areas....location and climate are everything.

Good luck getting it to grow if you have any sheep around. They'll destroy it. My in-laws had some comfrey...but not after they had sheep.
DK

the hybrid bocking comfrey doesn't make viable seed so stays put but the bush will spread bigger and bigger from the root crown over time but digging and sharing the roots can control it, so if you plant it make sure you want it there. once there it would be hard without herbicide to kill it. it can grow back from just a tiny root piece. that said I  love comfrey and i have 20 of them throughout the property here.

Steve, I am with you.

I only have 6 comfrey plants but I plan to get some root cuttings from my plants and get at least four and maybe six additional plants.

I have never cut comfrey roots, but from what I hear, all I have to do is cut out a corner of one of my existing plants, snip out a few choice looking pieces of roots and drop them in the ground.

This year I also plan to try something else.  I intend to both plant, and then cover the ground around the comfrey plants (old and new) and inoculate with mushrooms.

Eric

It all depends on what kind of gardener you are. I am a maniac, every day i'm in there. Photo one, neat, comfrey around the wooden grow stations. It took quite some work to pull it out, because it works it's way in. If it got roots, i'll put it in some pot for later transplantation. On grass end i'm mowing it, so it tries to pop up there too, but it can't. It's out competed by the grass, but only because i'm mowing it.
On the right side you can see a comfrey popping up of the Bocking variety, it flowers a bit later and will get a lot higher, but it stays there.
Photo 2, i've given it to my friend who put it against a wall, it wins a foot a year, but it is contained. She mowes and she loves,loves,loves plants to be and just let them go. No problem for now.
I've given it to another friend, a couple, the male who has listened and tended most of the garden put it under an oak. She told me the beautiful see of blue made hert think of me. I told her keep it there. She didn't listen. Moved it in to the core food garden. A bit here, a bit there. Couple split up, no time for the garden, two year later, it's a mess, it's everywhere in their core garden.

It's a super plant, there is no better i would know of. It feeds the bees in march/april and in a good year october/november. I can just seize it and use the leaves as a mulch in the beds without fear of spreading it, or on the compost heap to cool it and keep it moist. I've quit mqking compost tea, because it reeks and is anaerobic, i worm compost it. There are whole topics on this, i don't need to elaborate. But don't plant one that seeds out, please, it is a lot of work at least, and a total disaster at it's worst. What if you move? What if you go travel a year? And so on.

Hey, thanks Hugo!

Don’t worry about spreading, all my comfrey is Bocking 14.  I ordered this for the deep rooting and abundant top growth.  Since I got it started it has really taken off like a rocket, though the first year it did occasionally look a little sad as it was establishing, it nonetheless persevered and now grows like mad.  I like to take about 4/5 cuttings per season, though it is so pretty that I just like to watch it attract beneficial insects.

I am certain that just about any root piece I stick in the ground will likewise grow furiously.  I guess my biggest concern is deliberately cutting into an existing plant.  Even though I know this won’t cause any serious harm to the existing plant (I plan on taking less than a quarter),  it still violates a no-harm instinct.  This is irrational to be certain, and I plan on replace the removed roots and soil with an equal volume of homemade mushroom compost just to give the “harmed” comfrey plant some really great fertility.  Further, I plan to really pile the woodchips inoculated with wine caps onto the ground around the comfrey.  Basically I plan to give an aggressively growing plant all the fertility it can handle.  

Am I overthinking this—probably yes.  But I would love to hear any critique of my plan.

And from the sounds of things, I am really pleased I did not plant common comfrey—that sounds like a never ending chore on s good day!

Thanks,

Eric

Hi Eric, i was speaking to Tyler, he's got seeding comfrey.
I don't believe small pieces of the Bocking varieties root will make it on theiir own, not mine at my place at least. I let them stand for two years, then cut the rootball in pieces that have and a big chunk of root attached to a big piece of foliage. Then i got 4 big chancers, those i spoil rotten, like you're about to. The rest of the small pieces i that have no foliage attached i nurse for in a pot in the shade. Just hope some will put up some foliage during spring. Most disappears.
But hey, there are so many kinds of comfrey out there. Somehow everybody is sure theirs is the bocking 14 variety? Everybody's got "the best" because they're so clever. I've taken mine from roadsides next to farms mostly so i'm not sure what on earth i got.
But anyway they love to be given good care Eric. Spoil them and they will give!

   Symphytum asperum – prickly comfrey, rough comfrey
   Symphytum bulbosum – bulbous comfrey
   Symphytum caucasicum – Caucasian comfrey
   Symphytum ibericum – creeping comfrey, Iberian comfrey[3]
   Symphytum officinale – comfrey
   Symphytum orientale – white comfrey
   Symphytum tauricum – Crimean comfrey
   Symphytum tuberosum – tuberous comfrey
   Symphytum × uplandicum (S. asperum × S. officinale, synonym: S. peregrinum) – Russian comfrey, healing herb, blackwort, bruisewort, wallwort, gum plant

permies comfrey varieties.

Hugo,

Come to think about it, my original whole root pieces did not do as well as I had hoped.  Part of this was because of nonstop rain and completely submerged comfrey plants.

I may start them in little peat pots to get them off and running, then plant the pots once they look healthy.

Eric

i gave no care to my comfrey other than mulch and they get huge! matter of fact , they establish and grow quicker in marginal soil. i just dig out a plug of sod, push in a 1in. root cutting in about a inch, then mulch. grows every time. not saying they won't benefit from some compost but from what I've seen they really don't need it. save your compost for your veggies. Eric, my wine caps grow great under my comfrey. ;)

Thanks Steve,

Actually I was bringing in mushroom compost as much for the comfrey sake as to start more mushrooms!

But you are probably correct in that I am overthinking things—the comfrey I planted a couple of years ago is going gang busters.  Actually, it was the success of the existing comfrey that made me want more.

Thanks for your help Steve, for now and for in the past!

Eric

your welcome! keep up the good work!

I have creeping comfrey, bocking 14 and white comfrey. They seem to behave themselves if you cut them after flowering. I spend vastly more time weeding grasses out of areas my garden, they help to compete against grasses so I would not consider the comfrey invasive with my circumstances.

Henry Jabel wrote:I have creeping comfrey, bocking 14 and white comfrey. They seem to behave themselves if you cut them after flowering. I spend vastly more time weeding grasses out of areas my garden, they help to compete against grasses so I would not consider the comfrey invasive with my circumstances.

Yes! anything that can hold it's own against bermuda grass can stay and spread all it wants here.  

I do cut several times through the season for mulch and compost greens.  I'm hoping for some large enough patches eventually for scything.  The creeping one with brilliant blue flowers spreads much more quickly than the pink flowered clump one or the one with the 'live' seeds.  I love them all.

For me, in this area, where we have vinca, bittersweet, ivy and privit all encroaching from the creek out back, comfrey seems a friendly choice.  

I am rather new to gardening, so I was wondering if someone could explain me why you guys seem so fond of comfrey even though it is such a hard to contain plant? Does it have benefits that other plants don't have? What is it used for?
Also; is there a beneficial difference between comfrey and borage? The plants look very similar, and if I'm not mistaken they are related. Here in Italy borage grows wonderfully well, and is seen as a great beneficial plant for foraging purposes.

. the hybrid comfrey puts out a lot more leaf growth for chop and drop fertilization. also grows bigger than other comfrey and doesn't produce viable seed. i wouldn't plant the regular wild comfrey unless your just trying to cover poor land. once its there its impossible to get rid of. i also have a patch of borage and nettle i grow for my chickens. they prefer that to the comfrey.. it reseeds itself but its growing in partial sun so it hasn't spread much.

I bought some from a garden club. It had no ID on type but flowers blue. It’s helped establish healthy trees where I planted it. It breaks up the hard packed clay to help tree roots have an easier time of it. In one area it did spread, despite my harvesting for mulch regularly. Never dig it because that encourages spreading. I am going to sheet mulch over it where it spread too far. The only escapees are in my neighbors driveway. They just mow it. In the second area I planted it, the burdock is out competing it. It hasn’t spread.

It’s just too useful a plant. I use it in salves and tinctures, as well as mulch for the other garden beds and to make compost tea. It brings up nutrients from deep in the soil. If you are worried about it spreading, plant it in a container, a tall one.

In my soil, it is no more invasive than anything else I grow. Skirret can be invasive. Mine has walked all over the yard. My coreopsis made it all the way down to the corner. So has the Lamb’s ear. Invasive-ness will depend on your environment. I harvest the comfrey flower heads and toss them in a rain barrel for compost tea diligently but they still spread slowly. It likes growing in partial shade. Try a container first would be my recommendation. That’s how I grow nettles.

S.

Comfrey is perhaps the ultimate permaculture plant.  If it is a hybrid, like Steve mentioned already, it becomes something like a tamed weed, that is that it stays in place but yields up a great amount of leafy vegetation.  Being a perineal, comfrey will come back indefinitely and it’s foliage can be harvested several times a season.  Even better, the comfrey leaves are loaded up with nutrients mined up from deep in the subsoil thanks to a 6’ or more taproot.  Finally, the leaves can simply be dropped on the garden and be left to decay on its own.

It is almost like growing and harvesting your own compost.

Eric

Eric Hanson wrote:S.

Comfrey is perhaps the ultimate permaculture plant.  If it is a hybrid, like Steve mentioned already, it becomes something like a tamed weed, that is that it stays in place but yields up a great amount of leafy vegetation.  Being a perineal, comfrey will come back indefinitely and it’s foliage can be harvested several times a season.  Even better, the comfrey leaves are loaded up with nutrients mined up from deep in the subsoil thanks to a 6’ or more taproot.  Finally, the leaves can simply be dropped on the garden and be left to decay on its own.

It is almost like growing and harvesting your own compost.

Eric

Wel, that does sound mighty attractive. Do you mow it down to the ground several times year, or just remove some leaves every now and then that you drop and let the rest stay where it is? And where can one obtain this permie-super-plant hybrid, if you want to make sure it’s the non-seeding variety?

S.

I do not mow comfrey, I go out with a bill hook and cut just above ground level.  After that I go and drop the leaves somewhere they will do some good.

As for getting one of these wonderful little plants, I googled bocking 14 comfrey.  The Bocking 14 is generally considered the best for production, while Bocking 4 is generally considered one of the most resilient (but they are all so resilient it is hard to know what this means), though really there is not much difference.

If I remember, Coe’s Comfrey has a great reputation but only sells Bocking 4.  I found some Bocking 14 from someplace I have since forgotten.

At any rate, comfrey can be an easy, great addition to your permagarden.

BTW,  it was comfrey that first brought me to Permies in the first place as I was (am) on a quest to make my garden totally self reliant.  My aim is to need absolutely no outside nutrients.  I am very nearly there.  Comfrey has been a great addition to my garden, which is why I want to try more.  My focus now is getting fungi into the garden beds (they are raised beds of woodchips), a task I am assigning to wine caps and eventually oyster mushrooms.  By this point the only amendments I give are woodchips I chip on my own land and occasionally diluted urine that comes from me.

Good Luck with your endeavors

Eric

I have some of the common comfrey growing a few places in the PNW and have had no signs of invasiveness.  Oe area is a grass pasture that gets mowed for hay each year - there are some decent sized plants growing, but they are sparse and just in one moist area of the pasture.  The other are is a shaded hillside that has some sparse plants but they are small and don't create a covering.

I'm inclined to not worry about invasiveness, and would even say that the bocking varieties spread more and grow more robustly, so I would prefer those  And propogating those by root cuttings is very easy...

In my ecosystem, Comfrey sometimes grows well, but it doesn't spread much, and is easily controlled.

I was considering some Dwarf Running 'Hidcote Blue' comfrey for a lot I own.
The soil is at least somewhat contaminated, so my food plants are fruit bearing and/or planted in raised beds.
I cut the grass,  but I hate having to.
Here's how Sean at Edible Acres describes the plant:
" A running version of comfrey (yikes!)... Only gets about a foot tall. Makes an insanely strong groundcover for orchards, vineyards, etc., incredible sources of nectar for bees all summer, amazing soil protection from erosion and drying. Very important to design appropriately with a running spreading comfrey! :)"

No mowing,  and I get comfrey?
It's  so tempting,  but also a potential catastrophe waiting to happen,  at least for me.
The guy living next to my lot has already sprayed and killed trees on my lot, he wouldn't hesitate to herbicide anything that crossed the line onto his land,  and he would call the law as well.
Well,  it might be bad in the winter anyway.
I've noticed nothing seems to thrive under its leaves,  but they still die back in the winter, leaving that space somewhat bare.
I wonder if there is a good partner plant that could survive  under the shade of the comfrey and thrive when it dies back.

The worst part of me wants to raise a bunch in containers, and then throw "root bombs" on barren bits if land, like hellstrips or the back yard of a certain aforementioned tree killer...

It might be fine at my house,  where I could corral it with concrete walls and a chicken moat.

Just purchased some seeds with intent of helping out the local pollinators and use the leaves to promote composting. Earth care Seeds, Heirloom, Non-GMO, zones 4-9. Suggestions?