Any seasoned gardener knows that comfrey is a controversial herbaceous plant. Ok hold up there. Don’t run screaming because it can be invasive and potentially a nightmare to eradicate. More about that later.
Comfrey is a perennial herb, pretty much every permaculture gardener’s friend. Everywhere you go, you read or hear about permaculture and organic gardening folks using it. I typically avoid mainstream anything, and this is a mainstream recommendation in the permaculture world. But the more I discover, the more it doesn’t matter if it’s mainstream or not. It’s simply a great plant.
Here is a great video on the subject.
At our garden club, another community gardener had an abundance of comfrey growing. So Jim (a fellow gardener) and I chopped it all down, with permission. We piled the leaves under every tree, in the community orchard, for mulch. Wow, it smelled great when chopping it too.
Controlling the spread of comfrey
Comfrey is invasive if you don’t know what you’re doing. It will pretty much stay put if you don’t allow it to go to seed, but mostly, do not rototill or dig it up. You will be effectively creating a zillion broken off roots, where each one will develop its own plant. You cannot uproot the whole thing.
If you want to get rid of the stuff, you pretty much have to smother it with cardboard and mulch. Or build a hot compost heap on top.
Which strain is best for gardening?
There are two main types of comfrey usually used in organic gardening. They are Bocking No. 4 and No. 14, though there are 21 altogether. Each has different characteristics, beneficial in different ways. No. 14, (Stephenson strain, called Russian comfrey), is most often used in compost, for compost tea, and enhancing the soil. No. 4 is principally used for livestock fodder. Here is an excellent article on the two types of comfrey most widely used, Russian Comfrey: Bocking 14.
I gleaned this comment from Permies forum:
- For a strictly medicinal use, the true comfrey S. officinal seems to be more in favor
- For fodder, the B-4 seems most popular
- For compost/tea production, the B-14 seems the most productive
So in the Spring, we’ll be planting some comfrey between the two rows of daffodil (and/or elsewhere nearby) within the tree rings at the orchard. I also plan to have it in our garden plot.
Comfrey leaves can be chopped (or mowed) and dropped right in place, several times each season. You can also allow it to grow fully. It will literally flop over onto the ground by itself, not requiring chopping. It breaks down rapidly and regrows.
Comfrey is a dynamic accumulator, adding calcium and other minerals to soil. All varieties of flowering comfrey are beneficial insect attractors. The roots, due to their extensive system, aerate the soil and break up hard clay.
Comfrey is resistant to disease and pests. It usually requires no care whatsoever. Comfrey will also stop flowering about the time fruit blooms appear, not competing for beneficial insect pollination.
Comfrey can also out-compete grass and weed growth within the tree ring, or in other areas.
Comfrey tea can be brewed to water plants. You simply chop the leaves, put them in a watering can, bucket or larger container and cover with (preferably non-chlorinated) water. Let it steep for at least 24 hours, up to five days. Strain and spray or water plants with it. It’s a great nutrient boost.
The whole plant (true plant mentioned above) can be used medicinally. It’s called “bone knit” because of the rapid healing of bones and tissue from a poultice over injured parts. Many people tell not to ingest comfrey due to liver toxicity, but I would research those claims thoroughly to make your own informed decision (the two links later in this paragraph). This is a great resource to learn more about this aspect, from A Modern Herbal on Comfrey. And here is a more detailed discussion on the safety of comfrey.
When we harvested that large amount of comfrey to mulch the orchard, I was carried away by the fragrance of the leaves. Even the garden variety would likely be a good tea or herb to use.