Weeds are defined by Webster as "a plant that is not valued where it is growing and is usually of vigorous growth; especially : one that tends to overgrow or choke out more desirable plants." Notice that Webster makes no claims about where the weeds have come from. The USDA lists both introduced (invasive) and weedy plants as weeds. So what is a weed? There's really no right answer, but for the sake of this post I'll address common invasive plants that have the potential to overgrow the other plants in our yard. While generally in favor of a biodiverse lawn, these are plants I remove.
Canada Thistle is in fact not native to the U.S. or Canada; it's a European thistle. It's deep rooted, prickly, and grows pretty quickly. It can grow pretty much anywhere in the yard and has spread through most of the U.S. Most states list it as a noxious weed. It can travel large distances because finches will feed on its seeds, and as they fly through your yard or feed at your feeders, they deposit the seeds.WI DNR on Canada Thistle
Quack Grass is a plant native to Europe that often grows in our yard, flower beds, and even in our flower pots. It's native to Europe as well and spread through most of the United States and Canada. Quack Grass grows very quickly, spreads rapidly, and from my experience seems to be able to take over turf grass. This stuff will grow anywhere. I've also found it difficult to mow with the push-reel mower when it grows in a bunch. Quack Grass on USDA
Yellow Sweet Clover and Red Clover These clovers are not native to the U.S. The Red Clover is native to Europe and parts of Western Asia. It's a nitrogen fixer and grows in your lawn along side white clover. It has pretty purple flower and large leaves with a characteristic light water mark on the leaves. Yellow Sweet Clover is in fact not a clover at all. It's native range is also across the pond. It will overtake natives. Sweet Clover can grow tall and shade out native plant species.
Bird's Foot Trefoil is vine-like crap that grows along the ground. I personally have a terrible time getting rid of this one. It spreads quickly and creeps out of the yard over the curb and into the street. It may also appear in driveway cracks and disturbed soil. This plant is available for purchase and can choke out other plants in your yard or garden. Bird's Foot Trefoil at the Minnesota DNR
Canada Thistle
Bird's Foot Trefoil
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ReplyDeleteThe most noxious weed in central Wisconsin is actually a grass-Reed Canary Grass-and it's taking over much of the land where native plants used to flourish. This is a European introduction. The grass itself is useless as nothing feeds on it except for goldfinches on the seeds.
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