All summer, while waiting for a bunch of work to get done on our house, I’ve had visions of transforming the backyard so as to include a much expanded vegetable garden, along with a bunch of native shrubs and flowers and a bigger medicinal herb garden for my wife. Then on Monday the City of Kalamazoo’s “View from the Curb” waste disposal newsletter came. Usually I look at this only to see when bulk pick-up days are, but I had a couple of minutes to kill and skimmed through it. Towards the end it had a little feature on Japanese Knotweed [pdf], a bamboo-like invasive species that has been spreading due to the usual combination of human ignorance and biological will to power.
Yesterday while beginning my landscaping project, I saw what I thought was some J.K. just on the other side of our neighbor’s fence. I sent pictures to the email given in the “View,” and promptly heard back from city-worker Hannah Hudson, who came by and verified that we have been invaded. Japanese Knotweed, I learned is, the massive fear I now feel for my backyard and property value aside, a pretty amazing plant. Nearly anything you do to try to kill it will only make it stronger. A fingernail-sized clipping can root and become a new plant, so you don’t want to cut it. A severed root will send up shoots, so you don’t want to dig it up or even dig near it. Round-up makes it grow faster. There are, apparently, some herbicides that have some effect, but they’re really nasty and stay in the soil for some time. Hannah did say you can eat the shoots like asparagus, however, and one of the few effective ways of containment seems to be cutting shoots as they come up in the spring, so, until I learn more, that’s what we’ll be doing (cutting, anyway; we’ll see about the eating). But now I can’t dig anywhere I was planning to, so knotweed is about the only edible I’m going to be growing until someone figures out the silver bullet that will kill this stuff.
UPDATE: There is hope! Anna K. of the Kalamazoo Nature Center recommends trying careful physical removal of plants and roots at this stage, followed by careful monitoring for new growth and chemical treatment only if absolutely necessary. So a garden may yet be in my future! (If the neighbors understand the need for eradication — right now it’s only on their property, but it will soon be on ours.)