In which our heroine attempts to eradicate well established comfrey plants which are tragically misplaced in the garden.
Everyone makes mistakes when they start gardening. Putting comfrey plants at what I thought were going to be the corners of the garden was one of mine. The garden has expanded twice since those plantings, and two comfrey plants are now positioned where I've decided there should be pathways. Comfrey is legendarily difficult of removal, and these plants seem to find their current locations quite agreeable.
I have a method to my madness, or so it pleases me to think. I've had a few years to observe the way comfrey grows, and how other plants behave around it. I've noticed that:
- comfrey leafs out early in the spring
- comfrey dies back late in the fall
- one comfrey plant generally gets to about 3.5' (~1.1m) in diameter
- nothing - I mean no plant - grows under the full shade of an established comfrey plant
So the first step in eradicating the comfrey was to take divisions of the roots and transplant them to the northern end of the garden. This area was heavily lasagna mulched in fall of 2009. The mulch did a decent job of holding the weeds in check all through last year. But as you can see, it would need renewal this year to keep the weeds back. I'd much rather create a self-maintaining border composed of a plant so profoundly useful, and not ever have to give that area another lick of work. With the help of our first WWOOF volunteers of the year, I took some dormant root pieces and stuck them in small holes in the unimproved soil at the garden's edge back in late February, spaced roughly 3.5' apart. I did absolutely nothing to help these roots along, and after watching for about a month I only needed to put in second root divisions at two of the transplant locations. I now have obviously viable comfrey plants at each of the ten orange flags in the picture above. I may expand the comfrey hedge along the western edge of the garden at some point.
Aside from getting rid of comfrey plants where I no longer want them, relocating comfrey seems to make good sense from a fertility perspective. I think of comfrey as a miner plant. It grows a formidable taproot and pulls up nutrients from deep underground, making them available to more shallowly rooted plants. But every mine plays out eventually. These comfrey plants have been in place for four years. Putting new plants in a new area should grant access to untapped resources. Comfrey is also a plant with an extraordinarily large surface area for its size. The leaves are very broad and long, while the stems are minimal. I don't know this for a certainty, but that would seem to suggest that comfrey transpires a lot of water vapor, well supplied by its tap root even when the soil surface is relatively dry. In times of drought that moisture would be helpful to other plants nearby. At the same time, by covering so much soil, comfrey regulates temperature and slows water loss from the soil through evaporation. Even if I'm wrong about comfrey's utility to nearby plants, establishing an entire row of these plants where nothing but grass was growing before seems like a good idea. It will store carbon in the soil, provide more food for bumblebees, and serve as convenient a trap crop for Japanese beetles, making them easy to handpick for the hens.
So much for all the benefits of moving the plants. But how do I imagine I'll eradicate the comfrey from its current location? Well, I plan to take a multi-pronged and long term approach. And to be philosophical about it, rather than allowing my personal feelings to come into it. Now that I know the root divisions have taken, I'll basically just keep cutting back the growth of the parent plants. I expect to take at least six cuttings this year, and I don't expect to win the war in one year. The first spring cuttings from the comfrey will, as usual, be used to provide some extra fertility to the potatoes when I plant them. This year I may also use comfrey cuttings to give the corn a boost as well. After that, I'll take several cuttings to dry for the chickens' winter feed, and also feed it to them fresh. I will even let them have direct access to the comfrey occasionally so that they can do some damage on their own; although I know they'll be far more interested in eating all the critters living below the mulch that the comfrey creates from its own leaves. The damage to the comfrey itself will be purely collateral. Other than that, I'll just keep cutting back the top growth of the plants, so that the roots gradually deplete themselves. Without leaves to photosynthesize, the roots will eventually starve and die.
Depending on how it goes, I may experiment with solarizing the root mass at some point. This would entail covering it with clear plastic and weighting down the edges so that the roots are both deprived of water and baked by the sun. It sounds torturous, I know. The only thing that salves my conscience is knowing that I've already provided for the continuation of the plant's genetic line.
Tune in later this year to see how fares the war. And wish me luck.