“The difference between a weed and a flower is a judgement,” as goes the famous saying by self-help guru Wayne Dyer. However, as an avid gardener, you should well know the flaws in this statement. Weeds typically aren’t bred for beauty the way most sought-after flora is; weeds have evolved to grow aggressively, killing or severely weakening the plants around them by stealing water, sunshine and other nutrients. While some weeds can start out quite pretty, most quickly become eyesores as they take over an entire yard and decimate the plants you wanted to grow.

In fact, some weeds are judged by essentially everyone as weeds because of how they look and behave. If you want to save the appearance and health of your lawn and garden, here are a few of the worst weeds to watch out for – and what to do if you spot them.

Yellow Nutsedge

A perennial, grass-like weed, yellow nutsedge will blend into your lawn until it is too late to get rid of it easily. This weed’s tell is it’s super-fast growth: If you mow and see yellow grass sprouting above the rest of your lawn, you’ve been invaded. The key to getting rid of it is spraying herbicide early in the summer and growing your lawn at the proper height, which will keep it thick and crowd out any weed growth.

Ground Ivy

ground ivyAlso called creeping Charlie, cat’s foot, field balm and dollar weed, this garden menace rapidly spreads to create a dense mat that kills everything else. Most gardeners agree that the only way to beat back ground ivy is through hand-weeding, year after year. Ideally, you should pull the weed out before the seeds have developed; then, you should try to keep your garden beds a bit drier. If you let ground ivy get going, you should hire professional weed control services to fight this fight.

Crab Grass

Decided by some to be the number-one worst weed (largely because of its hardiness, which allows it o grow in every U.S. state), crab grass grows everywhere in your yard, but it is a particular blight on your veggie garden. The key to crab grass’s success is its rapid sprouting after summer heat has set in. If you know how to spot crab grass and successfully remove the main crown and any auxiliary nodes, you might be able to avoid seeing it next summer.

White Clover

Some gardeners like the look of white clover as a ground cover, but because white clover is relatively short-lived – and thrives only under specific conditions – it isn’t great to have in addition to your lawn. That’s because clover competes with grass for resources like water, sunlight and nutrients, and it will likely damage your lawn before dying out itself, leaving a patchy, brown eyesore in your yard. As with other weeds, the best offense is a good defense, with a densely growing turf and a thick layer of mulch.

Bindweed

bindweedAnother weed with a slew of fanciful names – creeping Jenny, lady’s nightcap, hedge bells, possession vine, etc. – bindweed is actually a cousin to the sweet potato. Unfortunately, unlike weeds like purslane and dandelion, bindweed isn’t delicious or nutritious, just pernicious. One of its nicknames is “zombie plant” because it is so difficult to kill; its roots can dig 30 feet underground, and the seeds can remain viable for 50 years! There is no chance of eliminating bindweed once it is established, but if you recognize its vines and arrow-shaped leaves just sprouting, you might be able to avoid an infestation with hand-weeding.

Canada Thistle

As its name suggests, Canada thistle is prickly, meaning hand-weeding requires strong gloves and a stronger determination. You can also try chopping the plant and pouring a mixture of vinegar and salt down its stem. Vinegar is a broad-spectrum herbicide and can harm the rest of your garden, but if you administer the weed-killer before a rain, you should find success.

Quack Grass

There’s little funny about quack grass, which spreads via underground rhizomes that release chemicals that stop other plants from growing. You can’t get rid of quack grass without eliminating these runners, which you can do with a fork to loosen the soil, a rake to reveal the roots and a cultivator to pull them out. Try to avoid handling the roots too much, or they will break and remain in the soil, allowing the weed to persist.

Weeds aren’t always a gardener’s worst enemy – but these ones are. Instead of wasting time wondering if that strange plant is going to produce a brilliant bud, you should identify it and eliminate it before it stifles the other plants you are trying to grow.