Japanese Knotweed

I live in downtown Vineyard Haven, and I wanted a garden. The former is a simple geographical fact. But the latter, my stated desire, was not so simple. It was the seed of an idea. It wasn’t a crazy idea. Many noble beings before me have set out to do the same, and with much success. So how could I have guessed that a garden in the overgrown, raised concrete retaining wall behind our building would be so hard? Two words… Polygonum cuspidatum, commonly known as Japanese Knotweed. And lots of it.

If you’re an experienced gardener, then you’re likely familiar with this plant, and would have known from the get-go that this is one plant you don’t easily weed out to make a garden. No. You pick another spot. With large, woody taproots that often tunnel many feet below ground, this bamboo-like plant loves to hang out in disturbed areas like this abandoned and over grown space at the back of our lot. And it wasn’t going to go easily—or in my case, at all.

Last spring’s experience with my first garden in many, many years did present some unexpected opportunities. Though it wasn’t quite the harvest I dreamed about as I planned in February, it did offer a very intimate, and sometimes infuriating, relationship to Japanese Knotweed—a plant that I have learned is both hard to get rid of, and, thankfully, delicious. Up rooted and overshadowed were the mustard greens and Swiss chard; the tomatoes and peppers didn’t thrive either, as this alien invader pushed up under their feet and, within mere days, stole their beloved sunlight.

Rumor has it that this invasive and familiar plant made its way to America as an ornamental when Frederick Law Olmstead was furiously weaving together plans for New York City’s Central Park and Boston’s Emerald Necklace. No doubt, the bamboo like appearance, broad leaves, and dainty greenish-white flowers are pretty to behold, and are likely what attracted many gardeners to it in the early 1900’s. In no time, they would quickly learn that controlling the plant was another story. It left gardens, fences and gardeners in ruins as it quickly spread and took over. Today, with thousands of varieties of flowering plants to choose from, Japanese Knotweed has been banished from the garden and subjugated to our waste places. There, you can easily find it flourishing on roadsides and recently disturbed ground.

The good news? It’s not all bad—in fact, it’s good…as in tasty.

Early last spring, I removed what I thought to be most of the taproot of the several well-established plants that inhabited the space I intended to use for more civilized plants (meaning the ones I wanted there). But I found the unmistakable asparagus-like shoots of the Japanese Knotweed emerging from the same soil just after I’d transplanted my carefully raised seedlings. I’d read Euell Gibbons account of eating and preparing the shoots, and so I decided to snap off the six-to-eight inch invaders and give it a try. To say that they look like asparagus is not to say that they taste like asparagus. No, they have a flavor that is distinctly unique, but entirely agreeable. Following Euell Gibbons suggestion further, I brought them in and prepared them much the same way I might asparagus. After rinsing them of garden soil, I added them to boiling water for just a couple of minutes (Knotweed takes less time to cook than asparagus, and can turn into a gooey mess if you overcook it). Once it was tender, I added a little salt, pepper and butter, and voilá, a perfectly good dish.

So, while my garden of many greens and veggies faltered under unceasing pressure from just one plant, I enjoyed the fruit from the one harvestable thing I was going to get out of it. Hot, chilled, alone or in a salad, I ate Knotweed. And once I’d finally given up on the garden altogether, I waited until the Knotweed was several feet high, carefully peeled the outer skin of the stalk off, cut it into bite sized pieces, and cooked it down, in a little water, revealing a tangy, flavor much like rhubarb (it can be used in the same ways).

This year, keeping fresh in mind the power that Japanese Knotweed possesses to devour hours and hours of hard, physical work and planning, I’m not so sure I’ll be repeating the same mistake. But, either way, I know that I can rely on an easy harvest that is sure to sprout anyway.