Principles vs. practice: a replacement for comfrey

Greetings permies! (Uh, permians?)

This being my first post, i will start with a brief introduction by saying that i grew up in a gardening household and also worked on a commercial farm seasonally. I am a botany enthusiast of sorts, having kept various exotic plants for years, and a physical scientist by education. As is often the case with childhood inculcation, it didn't occur to me to question the way things were done in the home garden i grew up with, in spite of being naturally skeptical. As i stumbled upon this site and similar ones recently, it was fascinating to discover the various schools of thought and numerous techniques for horticulture going around these days.

I'd like to employ permaculture priciples, but optimize the traditional practices along the way, and it's easiest to separate the mere traditions from the true principles during the initial adoption. So, it is with that background that i ask for your input on a critical permaculture issue: embracing comfrey. I hope to avoid being burned as a heretic.

I can appreciate the importance of a compostable bioaccumulator with deep roots able to extract or recover deep minerals. I have my doubts about using comfrey for this purpose. These concerns come from the toxicity of comfrey to animals, its potentially irritating foliage, poor drought tolerance (from what i have read) and its inability to fix nitrogen.

It seems that the perfect bioccumulator would have the very deep and hungry, flood-tolerant roots and fleshy foliage of comfrey while fixing some nitrogen of its own, thriving in dry conditions (especially by drawing water from depth and having low transpiration loss) and producing a useful fruit or seed product.

Is there any other plant that has the potential of fulfilling these roles? Maybe a perennial succulent legume with particularly deep roots? What about potential candidates that might be selectively bred to fit that role (thinking of long-term permaculture tools)?

Perhaps something good might come out of a re-evaluation of this particular practice.

Regards

There may not be one perfect plant - different plants could be selected for different habitats.  But they would need to be tested for their ability as bioaccumulators. 

A possibility for my region is Desmanthus illinoiensis, Illinois Bundleflower, though I have not found it to be as drought tolerant as I would like. 

It seems that the perfect bioccumulator would have the very deep and hungry, flood-tolerant roots and fleshy foliage of comfrey while fixing some nitrogen of its own, thriving in dry conditions (especially by drawing water from depth and having low transpiration loss) and producing a useful fruit or seed product.

i like dandelion but most hate it. deep roots, bio-accumulator, hungry, vigorous, flood tolerant, drought tolerant, grows everywhere, self seeds, produces useful leaves, flowers, and roots for food and medicine. the only thing is it doesnt fix N. but relying on a single soil building plant would be silly imo.

we have a mix of yarrow, dandelion, white clover, native clovers, chamomile as a basic ground cover here along with a few eatable "weeds" in the forest garden.

I love dandelion but have not been able to get it established at my place. 

While we permies love comfrey, be sure that embracing it is not a permaculture principle. It just happens to be very useful for a number of reasons. The leaves are not irritating to me, but that could vary from person to person. Comfrey does lose leaves in drought, but it seems to bounce back pretty quickly. I'm sure there are other, similar plants for drier climates. The leaves break down very quickly, which is why it is so valued as a soil builder.

Dandelions do have a lot of good attributes, but they don't get nearly the depth of roots or easily-composted green mass AFAIK.

I agree that relying on a single plant is not really a good idea, but finding a better tool for a job is a worthwhile pursuit.

you can get quite a bit of green material from properly managed dandelions, im not saying its better or anything, just a suggestion because it works well for me. one reason is you can harvest it more than comfrey. my comfrey can be cut to the ground every 4-5 weeks. 3' x 3' of dense dandelions(about one mature comfrey plant) can yield leaf cuttings every 2 weeks here in the growing season. which is a lot of greens from a small area. specially nutrient packed leaves for eating, chickens or compost. so every time i harvest the comfrey once, i get 2 cuttings from the dandelions.

but like i said i grow both and more for many many reasons.

Sweet clover, although it's also toxic to animals.  Or alfalfa, but that will only grow if the land is fairly fertile to begin with.

Look for wild legumes in ditches and along the roadside. 

Pouletic wrote:


I can appreciate the importance of a compostable bioaccumulator with deep roots able to extract or recover deep minerals. I have my doubts about using comfrey for this purpose. These concerns come from the toxicity of comfrey to animals, its potentially irritating foliage, poor drought tolerance (from what i have read) and its inability to fix nitrogen.

Not everything should fix nitrogen. 

Thanks for the comments.

It doesn't necessarily have to be a N fixer, i'm just giving that as an example of a positive attribute comfrey doesn't have that some other common bioaccumulators do.

Kirk Hutchison wrote:
While we permies love comfrey, be sure that embracing it is not a permaculture principle.

Paul worded it that way in another thread. I might have been preemptively overstating.

It just happens to be very useful for a number of reasons. The leaves are not irritating to me, but that could vary from person to person. Comfrey does lose leaves in drought, but it seems to bounce back pretty quickly. I'm sure there are other, similar plants for drier climates. The leaves break down very quickly, which is why it is so valued as a soil builder.

Well that's what i'm talking about: it's a fairly good all-around plant, but seems to have an abnormal number of fans considering the limitations. I'm thinking there must be better all-around plants to be had. Coming from a desert climate myself, the ability to grow in arid conditions (rather than just survive) seems like an important area for improvement in the go-to soil builder plant. Are you aware of anything like that with the same bottomless roots, etc. of comfrey?

rbrgs wrote:
Sweet clover, although it's also toxic to animals.  Or alfalfa, but that will only grow if the land is fairly fertile to begin with.

Do any of these have roots as deep as comfrey? It seems to be a standout in root depth for plants i see being commonly recommended as bioaccumulators.

Look for wild legumes in ditches and along the roadside. 

I definitely need to get out and prospect with this goal in mind. At the moment, i don't live in a dry climate but almost anywhere i am likely to settle that would have land to cultivate is likely to be that way.

Water-hungry perennials aren't always the best in my climate, due to long dry periods. Fava beans and borage do some of the work that comfrey might, for me.

Here's the way I've been using comfrey...keeps the foliage down to a minimum while keeping most of the benefits.

Let the comfrey die back from lack of water and watch the nearby plants take off.

The companion plants really love it.

Kind of a chop n' drop without the chop or drop...more of a die and dine.

After they've died back a bit I water the comfrey and it pop right back up.

Seems to be working well...

Favas set nitrogen, and mullein seems quite drought tolerant and has medicinal uses, as well as the seed stalks were used for torches, from what I understand.  Buckwheat can be tried and works well in some places. 

Amaranth can be a pain, but maybe some of the decorative kinds are less bothersome.

There are edible mums, but you have to have a taste for bitter I would say.  I let feverfew go where it will.  I used to have migraines, and once in a while I eat a leaf just for good luck.  Chinese people have traditionally used mums in tea in particular.  I have seen feverfew used in the florist trade as well.

Most brassicas seem to set pretty deep roots which till and can often just be left in place with the tops used.  I have had arugula that froze and then popped back up.

Personally, I use potatoes quite a lot, especially the pink and purple ones which seem hardier, and the flowers are prettier.  With good tilth, they are easy to harvest, just pull and harvest what comes up, leaving some to make more. 

I also find some alliums to be nice to spread around.  I have seen garlic wands sold for as much as $3.  I tell the neighborhood kids they are magic wands, and they seem to like that.  Shallots are handy because they push themselves out of the ground when they are ready to be harvested.  You can leave what does not come out easily.  They make a new crop.  Garlic seems to survive cold exceptionally well here in Portland.  Though slugs and snails bother garlic, they never take it totally down.