You would have to be an ass to refuse a taste of donkey rhubarb.

Donkey rhubarb is delicious, though not a relative of the garden variety many of us know better. More commonly called Japanese knotweed, this wild plant rivals regular rhubarb for the perfect pie and, best of all, it is a truly free food, found all over the Island. It is just now ready for harvesting, but will not last long in its tender, edible stage.

Its ubiquity, however, is unfortunate. Japanese knotweed has the distinction of being one of the world’s most invasive species, and is incredibly difficult to eradicate. It is such a threat to native species and habitats that it is considered a “controlled waste” in England under that country’s Environmental Protection Act of 1990. Furthermore, in Britain, it can only be discarded in specially-licensed landfills that are qualified to accept this plant.

So if you can’t beat it, eat it. Japanese knotweed is edible in its early stage as shoots and small stalks. It emerges as reddish knobs that turn into spears, which bear a resemblance to asparagus except for the large leaves that protrude from its joints. Cut it, and if it is hollow (similar to bamboo), you have found knotweed. Notice it in many waste places and along roadsides: on the sides of the Oak Bluffs dump road, behind Trader Fred’s and Your Market, and along the Tisbury overlook pull-off area.

Spring is the time to stalk this plant and collect the shoots before they get too large and lose their tenderness. One foot high is just right; any stalk over two feet is too big to harvest and will taste woody. To eat Japanese knotweed, you must first remove its thin outer skin. Use your fingers or a knife to peel it, but don’t go too deep or you won’t have anything but an empty hole. Crunch it raw – it has a sour, lemony taste – or toss it into a salad. As a vegetable, prepare knotweed as you would asparagus: sauté, steam, roast, or add to soups. Knotweed also works as a fruit and is tasty in pies, or even fruit soup, just like true rhubarb.

Most importantly, after you enjoy a nibble of knotweed, dispose of the plant wastes carefully. Never put this or any other invasive species in your compost pile or you will be fighting it in your yard forever. Neither should you bring it to your town’s compost pile. Discarded cuttings are one way that this invasive is spread around town and the island. A piece of knotweed as small as your pinky nail can grow into a new plant. Throw it away in a plastic bag as trash. Don’t be fooled by its name: it may sound like “not weed,” but rest assured it is a weed.

Eat hearty, eat well and eat the weeds, especially Japanese knotweed this spring. Harvest all you want; you can freeze it as you would fruit, for use later. Do your part to slow the spread of this powerful invader by tickling your taste buds with a weed from the wild.

Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown.