12 Common Weeds
Got weeds? Learn how to identify common weeds, including tips on why they’re thriving and how to get them under control.
When it comes to violets, opinions are divided. To some, it’s a weed of the vilest kind; to others, it’s a dainty wildflower. No matter which camp you support, it’s vital to know that while violets have a literary reputation of being shy, in the landscape, they are anything but that. This perennial bloomer boasts a prolific personality, spreading easily by underground stems and seeds. In the lawn, it adapts quickly to lowered mower heights, growing shorter as needed to dodge the blade. Violets thrive in moist, shady sites, but mature plants are drought tolerant. The solution to eliminating violets? Vigilant hand-weeding (be sure to remove all the rhizome) and targeted herbicide use.
Wild Onion and Garlic
These perennial weeds smell like their namesakes, and there’s no mistaking their presence when you mow over them. Wild onion has flat leaves, while garlic is round. They both grow from bulbs and form clusters similar to chives. To remove them, avoiding hand-pulling. It only serves to separate the main bulb from the tiny bulblets surrounding it, which remain in soil and sprout. To dig wild onion or garlic, excavate about 6 inches deep to get the whole bulb. Otherwise, spray with herbicide. The kind that kills nutsedge works on wild onion and garlic. In late spring, these weeds produce small bulbs atop long stems. Snip these and destroy them. They contain new bulbs—they’re this weed’s way of spreading and covering new ground.
Weed Tree Saplings
Keep an eye peeled in lawns and planting beds for sapling trees. Often these trees, like this walnut sapling, sprout thanks to the diligent digging of squirrels. It’s especially easy to miss these beneath mature shrubs or roses, until you spot the leaves poking through the plant. The other place that seedling trees pop up are along fencelines, courtesy of birds who have been gobbling fruit, such as mulberry, cherry or holly. Small trees are easy to hand-pull. Grab a spade if they seem firmly anchored in soil. Keep an eye out for seedlings in spring when weeding or mulching. Remove any you see before they have a chance to develop a tap root.
The nightmare of dandelions is the deep taproot (up to 15 feet long) and puffball seedhead, which disperses seeds on every breeze. The best defense against dandelions in the lawn is growing thick, healthy turf, which means mowing at the right height and fertilizing correctly. In planting beds and paths, these familiar weeds tend to show up in the worst places, such as rooted in the center of a perennial clump or tucked right in the edge row of paving stones. The best ways to get rid of dandelions? Spray them or dig them. When spraying, kick dandelions a bit first to scuff and wound the leaves—it helps the spray penetrate better. With digging, make sure you get at least 2 inches of taproot or they’ll return as two plants.
A non-native, invasive plant, garlic mustard grows in sun or shade, dry soil or wet. Its roots produce a chemical that inhibits other plants from growing. Thanks to these adaptations, it quickly colonizes areas. In many regions it’s displacing native forest plants, and in backyard gardens, it can quickly take over planting beds. Garlic mustard is a biennial, producing a small rosette of toothed, kidney shape leaves in Year 1, followed by a tall stem topped with flowers in Year 2. Remove (pull up stems and roots) and destroy any garlic mustard that appears on your property, putting it out with the trash.
Canada thistle brings a thorny problem to any landscape where it appears. This prickly beast grows from seed that can blow into your yard, or it can sprout from root pieces, which sneak in with bulk topsoil or mulch loads. Size varies, with many mature plants reaching 5 to 8 feet tall. In a single season, one plant can produce a 20-foot-long root system, and it only takes one piece of root to produce a plant. Control through weeding, but dig carefully and deeply to get the horizontal root. After digging, if another sprout appears, pull it, too. Or use an herbicide. The best time to spray is as soon as leaves break ground. Spray repeatedly through the growing season, and you will eventually kill it.
Braod-leaved dock appears harmless enough when the red-veined leaves pop through soil in early spring. What’s important to know is that this non-native weed has the capacity to produce 60,000 seeds per plant, with each seed able to remain alive (ready to germinate) in soil 80 years. This is one weed you do not want to set seed. Plants start out small, but grow up to 4 feet tall. Dock is a tap-rooted weed, and that weed reaches up to 4 feet deep into soil. Digging it out is mostly impossible. The best control is using herbicide or vinegar on the young leaves as soon as they appear. Scuff leaves a bit before spraying to ensure spray penetrates the leaf coating. Repeat spray as needed. The taproot can generate more leaves over time, but keep spraying. The root will eventually use all its stored energy and stop growing.
Also known as wild morning glory, bindweed is bad news. Hedge bindweed spreads by seed and creeping underground stems; field bindweed spreads by weeds and roots, which grow up to 30 feet deep. These plants open flowers that look like morning glory, which is why many gardeners let them grow. They’ll grow along the ground like a ground cover, but if there’s a support nearby, like a rose, fence or tree, the vines twine and climb. Since these plants are tough to eradicate, it’s important not to let any get a foothold in your yard. Pull them as soon as you see them, and continue pulling each time they emerge. It will take possibly years for the roots to exhaust, but you can eventually beat them this way. For quicker kill, apply an herbicide that kills the root. It may still take more than one treatment, but you will kill these persistent plants.
Native Americans called broadleaf plantain “white man’s foot,” because it seemed to appear everywhere white settlers went. Touted as a healthy backyard weed with various benefits, broadleaf plantain can create a small colony that resembles a ground cover if grass is thin and soil is dry and compacted. Hand pulling this weed is an effective solution, especially with small infestations. Plants have a fibrous root system and come up easily with a Three-Claw Garden Weeder. Or spray plants with an herbicide any time they are actively growing.
This weed grows in poor, wet, compacted soil (think heavy clay). When nutsedge arrives in your garden or lawn, left to its own devices, it can quickly take over, establishing a colony. It looks like a grassy weed, but it’s actually a sedge. The individual blades have a strong center rib and are triangular in shape—a shape you can feel and see. The worst thing about nutsedge is that it not only produces seed heads, but also forms small bulbs or nuts underground. You can pull a nutsedge plant and still leave a network of nuts in the soil, each one capable of generating a new plant. The best approach is to spray plants with an herbicide. For nutsedge that’s growing in lawn, be sure to choose a chemical that won’t kill grass. A popular chemical is Sedgehammer, and it usually kills nutsedge with one to two sprays.
This annual weed thrives in shady areas with moist, fertile soil, but it’s adaptable and can also sprout in dry areas. Chickweed forms a low-growing crown of stems that spread and sprawl. In a planting bed, the stems crawl through perennials and annuals, showing up as far as 12 to 18 inches from the plant’s crown. In lawns, it usually shows up in thin grass with heavy, moist soil. For a small infestations, hand-pulling works fine. Try to get plants up before they set seed, which can number up to 800 per plant. For heavy infestations, look for herbicides that list chickweed. There is also a perennial chickweed that spreads by seed and stem or root pieces.
Yellow Wood Sorrel
Also known as oxalis, this is a versatile weed that grows in sun or shade, moist or dry soil. It’s a clover look-alike, with heart shape leaves and yellow flowers. Blooms fade to form upright seed pods that explode when ripe, flinging seeds away from the mother plant. It also roots from stem pieces. It’s happy to grow in lawns, planting beds, gravel drives or vegetable garden paths. Oxalis is a common weed in nursery pots, so be sure to check before adding plants to your landscape. The best way to beat it in the lawn is to mow high and fertilize to grow a healthy, thick lawn. In planting beds, carefully hand-pull or spray with herbicide.HGTV.com talks about common weeds, including dandelion, wild violet, bindweed, wild garlic, thistle, chickweed, oxalis and garlic mustard. ]]>