42 Common Weeds in Lawns and Gardens: Identification & Control

Poison Sumac (Toxicodendron vernix)

Poison sumac is a shrub (some consider it a small tree) that grows in wet areas, often next to cinnamon ferns and cattails. You will not find it trailing over the ground or climbing trees, as you sometimes find poison ivy.

As is often the case with toxic plants, poison sumac can also be very attractive; its white berries and bright fall foliage make pretty, albeit potentially dangerous, yard accents.

How to control it: No matter what method is used, it might take more than one attempt to achieve complete success—and you might find yourself using several different ways. You can dig and pull, smother, or use herbicide. Whichever method you choose, wear long sleeves, boots, protective eyewear, and gloves whenever you are in an area where poison sumac is suspected.

Japanese Knotweed (Polygonum cuspidatum)

Polygonum cuspidatum goes by several common names, including Japanese knotweed and fleece flower. Several other common names include "bamboo" in them, such as "Mexican bamboo" or "American bamboo."

While its autumn flower does, indeed, look fleecy, "fleece flower" is just too dainty a name for so tenacious a weed. In fact, its appearance is tolerable only when it's in bloom, and, when the growing season is over, it leaves behind a patch of dried canes (often 6 feet tall) that are a blemish on any landscape. This highly invasive plant spreads via rhizomes.

How to control it: Knotweed requires a multi-pronged approach, such as constant mowing and herbicide application in spring or early summer and retreatment in early fall.

Crabgrass (Digitaria)

Crabgrass is so called because this grassy weed creeps along close to the ground, like a crab. In addition to mixing with lawn grass, it's often found growing in cracks in your hardscape. In doesn't appear until the weather gets hot.

How to control it: Being an annual weed, crabgrass perpetuates itself via seed—millions of seeds. To control crabgrass, you'll need to address the issue in spring when the plant is most vulnerable.

Use a pre-emergent herbicide to keep seeds from sprouting. To kill crabgrass, remove the plants by hand, roots, and all. If that doesn't work, use a post-emergent herbicide. Also, use an organic fertilizer to encourage the growth of lawn grass, which will crowd out the crabgrass.

Dandelions (Leontodon taraxacum)

Dandelions are a harbinger of spring. Their bright yellow flowers often poke up through lawns and appear between cracks in driveways and sidewalks. While these perennial plants have multiple medicinal uses and can be eaten in salads or used to make wine, many homeowners would prefer eliminating dandelions.

How to control it: Keeping dandelion seeds from germinating won't be enough to eliminate the plants. You can use herbicide to eliminate your dandelions, but the most effective and least harmful approach is to dig the flowers up from the roots. Since the taproot is long, however, this can be difficult work.

Plantain Plants (Plantago major)

A relatively innocuous plant, common plantain can be mowed whenever you mow the lawn. It tolerates heavy foot traffic and compacted soil which means that it quickly colonizes in any lawn that sees a lot of hard family use.

How to control it: Pull or dig up plantain weeds. Keep pulling them up before they can produce seeds. Eventually, the plant will give up. It may seem like a continuous process, but persistence is key.

Common Ragweed (Ambrosia artemisiifolia)

Common ragweed is easily identified by its deeply dissected leaves. It may be an essential weed for you to identify, even if you don't care about keeping your yard weed-free for aesthetic reasons.

If you're an allergy sufferer, common ragweed is a major source of sniffles.

How to control it: Ragweed can't tolerate constant mowing or rich soils. Maintain a healthy, mowed lawn in its place on a regular feeding schedule to keep ragweed at bay.

Giant Ragweed (Ambrosia trifida)

"Giant ragweed" is a summer weed named for its ability to grow up to 15 feet tall (making it easy to identify), with thick roots and branches. It's mainly a problem in the agricultural Midwest United States.

Like its ragweed cousin (and unlike goldenrod), giant ragweed produces a great deal of pollen which causes severe allergies.

How to control it: Giant ragweed seeds can produce up to 5,000 seeds per plant, dispersing via the wind. Its seeds can also live 10 years in the soil. This plant is a crop killer.

To keep it at bay, keep lawns healthy. Healthy grasses can keep giant ragweed from taking over. Tilling stands of seedlings can also disrupt their life cycle. If herbicide is necessary, employ a pre-emergent herbicide in the spring (Atrazine).

Hedge Bindweed (Convolvus arvensis)

Hedge bindweed has a reasonably attractive bloom, similar to the morning glory, which can be white or pink; it has a pleasant fragrance. But this is no innocuous weed. If you let hedge bindweed get out of control, this vine will soon entangle everything in your garden.

How to control it: Effective control requires prevention of seed production, deep tillage of the root system, and pulling out plants. Also, apply herbicides or landscape fabric on top of it to smother it. It needs light to grow, although it can remain dormant for up to five years.

Ground Ivy (Glechoma hederacea)

Ground ivy, a common lawn weed, goes by several names. For instance, it is also called "gill," "gill-over-the-ground," and "creeping charlie." Although considered a weed, ground ivy has a pretty flower, and when you mow this weed, it gives off a pleasing aroma. Ground ivy is also used as a medicinal herb.

How to control it: If you have a small area, dig and pull to remove this weed. It may be somewhat ineffective since stems or roots left behind can continue to grow and spread. Being persistent can lead to successful eradication. However, you can also rely on broadleaf herbicides applied in late September, then again a month later.

Purslane (Portulaca olearacea)

Purslane is a succulent in the Portulacaceae family with a crispy texture and interesting peppery flavor. It's also called pigweed, but it should not be confused with Amaranthus retroflexus, also called pigweed, which is an edible weed in the amaranth family.

How to control it: Purslane can be controlled well by hand pulling if you do it when the plant is young and before it goes to seed. If it's seeded itself, you can also use post-emergent broadleaf herbicide on young plants to eradicate them.

Stinging Nettle (Urtica dioica)

The flowers of stinging nettle plants are inconspicuous. However, you'll pay plenty of attention to its barbs if you're unfortunate enough to brush against stinging nettle.

How to control it: This plant is best managed by hand pulling. Wear gloves to protect your hands from the stinging hairs on the plant stems. Also, perform close mowing to prevent the plant from developing its fruit.

Curly Dock (Rumex crispus )

Curly dock (also called "curled dock" or "yellow dock") is found all across the United State. Each plant produces tens of thousands of seeds that remain viable in the soil for decades, leading to considerable invasive potential.

You'll be able to identify curly dock by its greenish blossoms that cluster in long thin flower stalks at the top of the plant. After the flowers have dried and turned brown, they remain in place, making the plant easy to recognize. Be aware that curly dock is toxic.

How to control it: You can control curly dock by tilling and uprooting this plant. Mowing will prevent seed production and reduce top growth. If it becomes problematic, apply a post-emergent herbicide in the fall. You can also apply herbicides in the spring.

Wild Madder (Galium mollugo)

Wild madder is, like sweet woodruff, in the Galium genus. It is a creeping, mat-forming perennial with pretty clusters of white star-shaped spring flowers and has fragrant, lance-shaped dark green leaves. Wild madder is also called "bedstraw." People used to use this weed as a bedding material.

How to control it: Bedstraw plants will flower, set seed, and spread seed if left alone. So mow Galium mollugo before it goes to seed to prevent its spread and give grasses a chance to out-compete the plant. Till and rotate the soil to kill perennial crowns and new seedlings.

White Clover (Trifolium repens)

The Irish consider various three-leaf clovers (such as the one in the photo) to be shamrocks. The tradition behind the shamrock is thus quite distinct from that behind four-leaf clovers. In addition to white clover, red clover (Trifolium pratense) is also common. Both have three leaves that contain a lighter marking in the middle. But red clover has a reddish-pink flower. While many consider clover a "weed," there's nothing wrong with mixing a little of it into your lawn. It is a low-growing, nitrogen-fixing perennial with many advantages over grass, including that it rarely needs mowing and tolerates dog urine.

How to control it: Clovers are relatively easy to manage in the home garden by hand-pulling, cultivation, and mulch application. In large, landscaped areas, herbicides may also be necessary. Clover seeds have a hard seed coat that is heat tolerant; composting and solarization do not kill the seed. It can survive many years in the soil, sometimes making eradication difficult.

Orange Jewelweed (Impatiens capensis)

Like curly dock, orange jewelweed (or "jewel weed") is known as a home remedy for poison ivy. The taxonomic name of orange jewelweed, Impatiens capensis, indicates that it is related to the colorful impatiens flowers commonly used in shady annual beds. Less commonly, the plant has yellow flowers.

How to control it: Spotted jewelweed has a shallow root system and should be hand-pulled whole, which is easier done when the soil is damp. If the plants do not have seed capsules, they can be composted; if they have seeds, bag and dispose of them.

Bittersweet (Celastrus)

There are three plants called "bittersweet." American bittersweet is harmless, but Oriental bittersweet is an aggressively growing invasive weed that can harm your trees. The third type of weed, bittersweet nightshade, is one of the most poisonous plants, despite being related to the tomato.

How to control it: The most effective method is to pull out bittersweet vines and roots whole; the roots appear long, intestine-like, and orange. You can also cut it down as close to the soil level as possible and use herbicide on the fresh stem cuts to eradicate the vines.

Horsetail Weed (Equisetum arvense)

There's more than one kind of "horsetail." Equisetum arvense is a thoroughly weedy-looking plant that will spread out of control if given a chance, even in dry soil.

Equisetum hyemale, by contrast, is a more useful horsetail plant to the landscaper. It is an architectural plant that can be employed as an accent around water features. If given moist soil, it will spread, so consider potting it up for use around water features so that you'll have firm control over it.

How to control it: Conventional methods like pulling, tilling, smothering, or herbicide are ineffective for removal. The best way to get rid of horsetail weed is to change the soil conditions drastically by improving the drainage, raising the pH, and increasing the soil's fertility.

Chickweed (Stellaria media)

Common chickweed (Stellaria media) is a low-growing winter annual that grows into lush green mats studded with small, star-shaped white flowers. It's weedy because it can grow in a wide range of soils. It thrives in acidic soils. It produces approximately 800 seeds and takes up to 8 years to eradicate.

How to control it: Chickweed is easy to control by hand-pulling if done early before it flowers, usually by late fall and winter. Also, use a layer of organic mulch wood chips or landscape fabric to prevent seeds from germinating or having the light they need to grow. You can also use a pre-emergent herbicide in early spring.

Canada Thistle (Cirsium arvense)

Canada thistle is an aggressive perennial weed from Eurasia designated as a noxious weed in 43 states. It has whitish, creeping rootstocks that emerge in mid to late spring. It reaches 2 to 4 feet tall, with flowers budding in July and August. It spreads via rhizomatous roots or wind-blown seeds.

How to control it: Canada thistle isn't easy to control because its extensive deep root system helps it to rebound easily. Its horizontal roots may extend 15 feet, and its vertical roots may go up to 15 feet deep. This weed's seeds remain viable for up to four years in the soil.

When first spotted, remove it by hoe before it becomes well-rooted. You might also need an herbicide applied for about two years to remove this thistle effectively.

Quackgrass (Elymus repens)

Quackgrass is a creeping, persistent perennial grass with rough, blue-green blades. It forms a heavy mat in the soil and reproduces with seeds. It can grow up to 3 feet tall.

This weed looks similar to annual ryegrass and crabgrass, but it differs because it has long tapered blades that are thicker than the average blade of grass, usually about 1/3 inch thick, and attached to a hollow stem. Quackgrass also has very deep rhizomatous roots.

How to control it: Maintain a dense, healthy lawn to keep this weed at bay. Dig out this fast-growing grass, including the roots, as soon as you see it in your garden. It's easiest to pull when the soil is moist. A non-selective herbicide like glyphosate can be used to control a small infestation in the garden.

Shepherd's Purse (Capsella bursa-pastoris)

Shepherd’s purse is a winter broadleaf annual flowering weed hailing from the mustard family. It produces heart-shaped seedpods with seeds that remain viable for several years in the ground. This plant aggressively reseeds itself. It typically grows best in full sun, dry conditions, and almost any kind of soil, including cracks in the pavement.

How to control it: Pull out this annual weed by hand or hoe before it seeds, removing the entire root. Afterward, mulch about 3 inches deep. Otherwise, use an herbicide (MCPA or 2,4-D) in early spring before it can flower.

Woodsorrel (Oxalis stricta)

Common yellow woodsorrel is a native North American weedy plant called shamrock or sheep's clover. It produces yellow cup-like flowers with five petals from mid-spring to fall.

This herbaceous annual can also grow as a tender perennial and is found in 46 continental United States. It can grow in most soils and conditions, even in the sidewalks' cracks.

How to control it: Common yellow woodsorrel is best managed by hand weeding and mulching. It pulls up easily and does not rebound from roots left behind. Remove plants before seed pods develop. Most herbicides are ineffective, but you can try pre-emergent herbicides to prevent germination.

Common Mallow (Malva neglecta)

Common mallow is a winter annual broadleaf weed called cheese mallow, cheese weed, and dwarf mallow. It gets its "cheesy" name for resembling a cheese wheel with wedge-shaped sections (each contains a seed). It can survive in many environments and soil conditions, including frigid temperatures, dry, compacted soils, and lawns that have been mowed too short.

How to control it: To control it, keep your lawn thick and healthy. It has a hard time establishing itself when competing with dense, vigorous turf that is maintained at adequate mowing heights, fertilization rates, and irrigation practices. If some mallow seeds sprout, pull young plants before they go to seed. The roots go deep and can spread up to 2 feet. You can also use pre-emergent and post-emergent herbicides to control it.

Lambsquarters (Chenopodium album)

Lambsquarters is a fast-growing broadleaf annual plant with seeds that are small and light enough to be blown by the wind over short distances. The seeds can sometimes even survive for decades in the soil.

How to control it: Pull or remove it with a sharp hoe before it goes to seed. It has a short taproot, so it pulls up easily. The plants die with the first frost and next year’s plants grow from the seeds they leave behind.

Pigweed (Amaranthus retroflexus)

Pigweeds are erect summer annual plants that germinate from seeds during late winter through summer, growing best in the warmer weather. They have simple, oval, or diamond-like alternating leaves with small, greenish flower clusters and a fleshy, red taproot.

How to control it: Pull out this weed before it flowers. Also, its seeds require light for germination, so to prevent pigweed seeds from germinating, cover your garden with a 3- to 6-inch layer of winter mulch.

Nutsedge (Cyperus spp.)

Nutsedges, or "nutgrasses," look like grass but are perennial weeds that out-compete many other plants, including garden vegetables, by diminishing crop yields. They produce light brown or reddish flowers and black or brown seeds.

You can identify them by their triangular stems. Roll the stems between your fingers, and you'll understand the saying, "sedges have edges." In contrast, grasses have round stems. Shiny, smooth nutsedge leaves have a distinct center rib and form a "V" shape.

How to control it: These plants spread by seed and remain alive perennially because of their underground rhizomatous root or small tuber, called a nutlet. Some of these tubers can go as deep as 18 inches, which is why this plant can return yearly. Remove these plants as soon as you've identified them; do not allow them to develop tubers. Tubers develop about four to six weeks after the shoot.

Dayflower (Commelina spp.)

Dayflower is related to spiderwort plants (Tradescantia spp.). This plant can make a pretty groundcover, but is considered invasive in some states.

Dayflowers are tough to eradicate because they are resistant to weed killers and can regrow quickly from broken stems. It's also tricky because it looks like a healthy, wide-leaf grass when it first sprouts.

How to control it: Mulch the garden to prevent it from germinating and use a pre-emergent herbicide in the spring for problem spots. You can also hand pull or use a non-selective post-emergent herbicide.

Velvetleaf (Abutilon theophrasti)

Velvetleaf (Abutilon theophrasti) is an annual weed that grows up to 8 feet tall. It has a stout stem with soft hairs, large, velvety, alternating round or heart-shaped leaves, and orange-yellow flowers with five petals. It is self-pollinating, so it doesn't require pollinators to set seed. It spreads via seeds that can persist in the soil for over 60 years.

How to control it: Single plants can be easily pulled or dug up before they go to seed. Mulch your garden to prevent velvetleaf, or use a pre-emergent herbicide in spring. Do not till or plow infested areas because this promotes seed germination. Crop rotation can stop velvetleaf from returning.

Wild Violet (Viola papilionacea)

Wild violet grows as a broadleaf perennial groundcover in clumps about 6 inches tall in shadier spots. It has heart-shaped leaves and purple, white, or yellow flowers in late spring or early summer. In many cases, it makes a beautiful ornamental, but if you do not watch it, it can overtake a garden.

How to control it: Mulch garden beds in spring to prevent wild violet. Properly fertilize, mow, and water lawns to encourage dense growth that discourages wild violets from taking hold. Pull weeds by hand or spray with a post-emergent herbicide in spring or fall.

Smartweed (Polygonum pensylvanicum)

Smartweed is an annual broadleaf plant growing upright about 42 inches tall with lance-shaped leaves marked with purple chevron-looking blotches. Its stems are divided into swollen segments called “knees” covered with pale green sheaths. The leaves have smooth edges and sparse hairs on the surface. This native North American plant has pink or white flowers in the summer and fall.

How to control it: It reproduces from seeds. Pull plant by hand or apply a post-emergent herbicide once it grows. To prevent this weed, mulch garden beds in spring.

Quickweed (Galinsoga parviflora)

Quickweed is a broadleaf herbaceous annual in the daisy family that grows about 2 feet tall and wide. It has jagged, hairy leaves and small white daisy-like flowers in the summer. It's also called gallant soldier, and if left unpulled, it can produce many generations until the first frost.

How to control it: Use a mulch or a pre-emergent herbicide in spring to prevent quickweed. These plants have a shallow root system and are easy to pull by hand or spot-treat with a post-emergent herbicide.

Pokeweed (Phytolacca americana)

Pokeweed grows all over the United States, sometimes up to 10 feet tall. This garden weed has light green leaves, clusters of white flowers in summer, and dark purple berries.

It has a large, fleshy taproot and reproduces by seed. A single plant can produce 1,500 to 7,000 seeds annually.

How to control it: Prevent pokeweed with a deep layer of mulch. Once the plant grows, hand-pull or spot-treat it with an herbicide. If allowed to establish, it will develop an extensive root system that will need to be dug out. If removing, bag its berries so they can't reach the soil.

Black Nightshade (Solanum nigrum)

Solanum nigrum, or black nightshade, is related to tomatoes and potatoes, although it is not edible as it's toxic to humans. It is a short-lived broadleaf annual that can grow as a 2-foot tall bush or climbing plant with white or purple flowers and purple or red colored fruits. It is susceptible to many of the same pests and diseases as other nightshade plants.

How to control it: Mulch your garden to prevent black nightshade. Pull the weed by hand or treat it with a post-emergent herbicide.

Black Medic (Medicago lupulina)

This plant grows in mats, is no more than 2 feet tall, and thrives in poor, dry soil and full sun. It has creeping stems, clover-like leaves, and small yellow flowers. It develops a long taproot that grows deeply. It can overtake weak grass since it spreads easily by seed.

How to control it: It has difficulty establishing itself in dense, well-kept lawns. Spread mulch to prevent black medic in gardens. Pull or dig out weeds by hand before it blooms and sets seed. It should be easy to pull when the soil is moist. You can also use a post-emergent herbicide, best applied late spring through early summer and mid-autumn.

Poison Ivy (Rhus radicans)

Most everyone has heard of poison ivy and the common expression, "leaves of three, let it be."

Poison ivy can grow up to 15 feet tall and wide in the sun or shade as a vine, shrub, or groundcover. Never touch this plant since its oil can cause a severe allergic reaction. The oil is noxious even on dead leaves; if burned, poison ivy is toxic if (inhaled).

How to control it: Prevent poison ivy with a deep layer of mulch. Spot-treat it with an herbicide or wrap your hand in a plastic bag or waterproof gloves and pull the plant up, roots and all. Carefully invert the plastic bag around the plant, seal it, and throw it away. It does not do well with repeated tilling, cutting, or mowing.

Barnyard Grass (Echinochloa crus-galli)

Barnyard grass is a summer annual that can reach 5 feet in height but usually stays about half that. It has thick stems (tinted maroon or reddish near the base), out of which leaves about 6 inches long protrude.

An identifying feature is the white midvein of the leaf. Showy flowerheads/seedheads appear at the top of the stem. These heads often mature to a purplish color.

How to control it: Hand pulling is usually sufficient to control barnyard grass, especially if you can remove it before it goes to seed. For prevention in lawn areas, focus on promoting a vigorous lawn through proper fertilization and irrigation practices. Mowing frequently will ensure that barnyard grass never has a chance to go to seed.

Goosegrass (Eleusine indica)

You can tell goosegrass from crabgrass due to the presence on the foliage of the former of a lighter-colored stripe running down the middle. Otherwise, the two weeds are similar.

How to control it: Just as goosegrass is similar in appearance to crabgrass, control measures for it are like those for crabgrass. Apply a pre-emergent herbicide in spring (check with your county extension for the best time to apply it in your region). For prevention in the lawn, promote a lush lawn by overseeding, fertilizing, and watering during droughts.

Annual Bluegrass (Poa annua)

This fine-textured annual plant is a cool-season grass, like its better-known perennial cousin. Its bright green leaf blades grow in tufts. Its greenish-white seedheads will help you identify it.

How to control it: Since annual bluegrass spreads only via seed, it's easy enough to remove it by digging it up if it occurs in only a few spots in the lawn. Also, as for other weedy grasses, sound lawn care practices can prevent it. If prevention fails, apply a pre-emergent herbicide in late summer or early fall.

Hairy Bittercress (Cardamine hirsuta)

This is a winter annual, meaning its seed germinates in fall, leading to vegetation that overwinters. It then blooms in spring and goes to seed (after which it dies). The weed grows in low rosettes. The small flowers are white, with four petals.

How to control it: Like other members of the mustard family, hairy bittercress produces a lot of seed. To control it, ensure that it does not go to seed.

Henbit (Lamium amplexicaule)

Henbit is related to the landscape plant, spotted deadnettle (Lamium maculatum). Both are in the mint family, which is known to spread like wildfire. To identify it, notice that henbit has rounded leaves that hug the stem.

How to control it: Henbit spreads mainly by seed. Since its purplish flowers are easily spotted, the best way to control plants already growing is through hand-pulling (before seed sets).

Since henbit prefers cool, moist areas, be sure to grow shade-tolerant grasses such as fescue (Festuca spp.) in shaded areas.This will help your grass out-compete henbit for light, nutrients, and water.

Lawn Burweed (Soliva sessilis)

This weed occurs in the U.S. mainly in the southern and western states. Also called spurweed or stickerweed, lawn burweed is another winter annual.

This low-growing weed has opposite leaves, divided into leaflets. The burs are problematic if you step on them, and if seeds spread, you'll be in for more plants to come.

How to control it: This is another weed you must stop by preventing seed production. Apply a pre-emergent herbicide in the fall or a post-emergent herbicide in the winter.

Bahiagrass (Paspalum notatum)

Bahiagrass is a perennial, warm-season grass with bright green blades that spreads via rhizomes. Its Y-shaped seedhead is a distinguishing feature. It tolerates poor soil and is also a heat-tolerant, drought-tolerant grass variety that can grow where many other grasses won't.

Unfortunately, all that tolerance makes it a tough weed to fight if you don't want Bahiagrass in your lawn.

How to control it: Since the plant spreads via rhizomes, you must remove the rhizomes to get rid of the grass. Small patches can be dug out, but, for larger patches, you must use a post-emergent herbicide in late spring.