Spiky pointed weed seeds

The Only Weed Identification Guide You’ll Ever Need: 33 Common Weedy Plants to Watch For

Don’t let these pesky plants crash your garden party! The first step is to know your enemy. Then you’ll know the best way to deal with your weed problem.

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What is a Weed, Anyway?

A weed can be any plant growing where you don’t want it to. However, there are some particularly weedy species to keep an eye out for. These aggressive plants not only make your yard look messy, they can also choke out the garden plants you’ve worked so hard to grow. Whether you’re trying to identify lawn weeds or garden weeds, this handy guide will help you identify more than 30 common weeds by photo, plus give you tips for how to best remove them.

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Dandelion

Type: Broadleaf perennial

Size: 12 inches tall, 6 – 16 inches wide

Where It Grows: Lawns and gardens in sun or shade

Appearance: This common lawn weed has a long taproot; leaves are deeply notched. Yellow flowers mature into puffballs. Dandelion seeds are like parachutes that fly away in the wind, helping them invade new spaces in lawns and garden beds.

Weed Control Tips: Mulch to prevent dandelions in gardens. Pull dandelion weeds by hand or treat lawns with a broadleaf herbicide, which won’t kill grass.

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Oxalis

Type: Broadleaf perennial

Size: To 20 inches tall

Where It Grows: Sunny or shady landscape, lawn, or garden areas

Appearance: This garden weed has light green leaves that look a little like clover and cup-shape yellow flowers in summer and fall.

Weed Control Tips: Mulch garden areas in spring to prevent weeds. Pull oxalis weeds by hand or spray weeds with a broadleaf herbicide in spring or fall.

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Crabgrass

Type: Grassy annual

Size: To 18 inches tall and 20 inches wide

Where It Grows: Lawn, landscape, and garden areas in sun or shade

Appearance: Crabgrass is exactly what it sounds like: A grassy weed. This lawn weed grows roots anywhere the stem makes soil contact. Seed heads spread out like four fingers.

Control: Use a preemergence weed preventer to prevent seeds from sprouting, pull crabgrass by hand, or spot-treat with a nonselective herbicide if growing in sidewalk cracks or other places where nothing else is growing.

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Bindweed

Type: Broadleaf perennial

Size: Climbs 6 feet or more

Where It Grows: Landscape and garden areas in sun

Appearance: Identify this garden weed by its arrowhead-shape leaves on twining vines. Bindweed also produces white to pale pink morning glory-type flowers.

Control: Mulch your garden to prevent bindweed. Repeatedly pull or cut down growing bindweed plants and/or spot treat with a nonselective herbicide designed to kill roots, not just above-ground growth.

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White Clover

Type: Broadleaf perennial

Size: 8-10 inches tall, 12 inches wide

Where It Grows: Lawn, landscape, and garden areas in sun to partial shade

Appearance: White clover has three-lobe leaves and round white flower clusters. The plants quickly spread outward to form dense mats of foliage.

Control: Mulch your garden beds to prevent white clover in landscape areas. Use an iron-based herbicide to get rid of clover growing in lawns or dig out the weeds in garden beds.

Test Garden Tip: Clover adds nitrogen to the soil plus the flowers feed many pollinators so some gardeners use this plant to create a more environmentally friendly lawn.

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Nutsedge

Type: Grass-like perennial

Size: 2 feet tall, 1 foot wide

Where It Grows: Lawn, landscape, or garden areas in sun or shade

Appearance: Nutsedge has slender, grassy leaves, triangular stems, and small, nutlike tubers on the root system. When these weeds pop up in lawns, they often grow faster than turf grass, so they are easy to spot.

Control: Mulch garden areas in spring to help prevent nutsedge. Plants are easy to pull up by hand, but it will take repeated weeding to get rid of an infestation. Various herbicides are labeled for use on nutsedge in lawns but it is important to use the right one for the type of turf grass you have to avoid damaging it.

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Creeping Charlie

Type: Broadleaf perennial

Size: 4 inches tall, several feet wide

Where It Grows: Shady lawn, landscape, or garden areas

Appearance: Identify this lawn weed and groundcover by its scalloped leaves, creeping stems, and clusters of purple flowers in late spring.

Control: Mulch garden areas in spring to prevent creeping charlie. Pull plants by hand or spray with a postemergence herbicide in spring or fall.

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Lamb’s-Quarter

Type: Broadleaf annual

Size: To 4 feet tall and 18 inches wide

Where It Grows: Landscape and garden areas in sun or shade

Appearance: Lamb’s-quarter’s scalloped, triangular leaves have gray undersides.

Control: Mulch your garden to prevent lamb’s-quarter. Pull weed plants by hand or use a postemergence herbicide.

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Plantain

Type: Broadleaf perennial

Size: To 8 inches tall and 12 inches wide

Where It Grows: Moist lawn and garden areas in sun or shade

Appearance: When you’re identifying weeds in your garden, if you spot broad, flat, oval-shape leaves arranged in a low rosette, you’ve likely found a plantain.

Control: Mulch to prevent plantains growing in the garden. Pull these weeds by hand or use a postemergence herbicide in lawns.

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Dayflower

Type: Annual grass relative

Size: To 30 inches tall and wide

Where It Grows: Sunny or shady landscape areas

Appearance: Dayflowers have dark green leaves sprouting from a stem and brilliant blue flowers through the summer.

Control: Mulch the garden to prevent weeds or use a preemergence herbicide in spring. Pull weeds by hand or spot-treat with a nonselective postemergence herbicide.

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Purslane

Type: Broadleaf annual

Size: To 6 inches tall and 2 feet wide

Where it grows: Dry, sunny landscape and garden areas

Appearance: Identify this weed groundcover by its fleshy, dark green leaves and small yellow flowers at the ends of the stems.

Control: Mulch your garden to prevent purslane or use a preemergence herbicide in the spring. Pull plants by hand or spot-treat with a nonselective postemergence herbicide.

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Velvetleaf

Type: Broadleaf annual

Size: To 6 feet tall and 3 feet wide

Where It Grows: Fertile, sunny landscape and garden areas

Appearance: Velvetleaf gets its name because of its large, velvety heart-shape leaves up to 10 inches across. The weed blooms with yellow flowers in summer.

Weed Control: Mulch your garden to prevent velvetleaf or use a preemergence herbicide in spring. Pull existing plants by hand or use a postemergence herbicide.

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Wild Violet

Type: Broadleaf perennial

Size: 6 inches tall, 6 inches wide

Where It Grows: Shady lawn, landscape, or garden areas

Appearance: Wild violet is a groundcover with heart-shape leaves and purple flowers in late spring.

Control: Mulch garden beds in spring to prevent wild violet. Pull weeds by hand or spray with a postemergence herbicide in spring or fall.

Test Garden Tip: This plant is sometimes grown as an ornamental in shade gardens.

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Smartweed

Type: Broadleaf annual

Size: To 42 inches tall and 30 inches wide

Where It Grows: Sunny landscape and garden areas

Appearance: Identify garden weeds like smartweed by its lance-shape leaves often marked with purple chevrons. It’s an upright plant with pink or white flowers in summer and fall.

Control: To prevent this weed, mulch garden beds in spring. Pull plants by hand or apply a postemergence herbicide once it grows.

Test Garden Tip: This weed is native to areas of North America. Unlike many exotic weeds, it does support local wildlife.

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Quickweed

Type: Broadleaf annual

Size: To 2 feet tall and wide

Where It Grows: Sunny landscape and garden areas

Appearance: Quickweed has jagged, hairy leaves and small white daisy-shape flowers in summer.

Control: Use a mulch or a preemergence herbicide in spring to prevent quickweed. If plants do grow, pull them by hand or spot-treat them with a postemergence herbicide.

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Pigweed

Type: Broadleaf annual

Size: 6 feet tall, 2 feet wide

Where it grows: Sunny landscape or garden areas

Appearance: Pigweeds are tall plants with a taproot. Identify weeds by their hairy-looking clusters of green flowers (though some varieties are grown as annuals).

Control: Mulch garden areas in spring to prevent pigweed or use a preemergence herbicide in spring. Pull weeds by hand or spray with a postemergence weed killer.

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Canada Thistle

Type: Broadleaf perennial

Size: To 6 feet tall and 3 feet wide

Where It Grows: Sunny lawn, landscape, or garden areas

Appearance: Canada thistle has spiny, gray-green leaves and purple flowers.

Control: Mulch your garden to prevent it in landscape areas. Use a postemergence herbicide in lawns in spring or fall, or dig the weed out by hand.

Test Garden Tip: Thistle has an extensive root system that can grow several feet out from the main plant.

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Knotweed

Type: Broadleaf annual

Size: To 8 inches tall and 2 feet wide

Where It Grows: Sunny or partly shaded lawn, landscape, or garden areas

Appearance: Knotweed is an invasive groundcover with blue-green leaves sparsely appearing on long stems.

Control: Prevent knotweed with a deep layer of mulch or apply a preemergence herbicide in spring. Once the plant grows, hand-pull or spot-treat it with a nonselective weed killer.

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Pokeweed

Type: Broadleaf perennial

Size: To 10 feet tall and 2 feet wide

Where It Grows: Sunny landscape or garden areas

Appearance: Identify this garden weed by its light green leaves, clusters of white flowers, and dark purple berries.

Control: Prevent pokeweed with a deep layer of mulch. Once the plant grows, hand-pull or spot-treat it with an herbicide.

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Poison Ivy

Type: Broadleaf perennial

Size: To 15 feet tall and wide

Where It Grows: Sunny or shady landscape or garden areas

Appearance: Poison ivy can be a vine, shrub, or groundcover. The weed has leaves divided into three leaflets and can sprout clusters of green berries.

Control: Prevent poison ivy with a deep layer of mulch. If the weed starts to grow in your yard, spot-treat it with an herbicide or wrap your hand in a plastic bag, pull the plant up, roots and all, and carefully invert the plastic bag around the plant, seal, and throw away.

Test Garden Tip: The plant contains oils that cause a severe allergic skin reaction in many people when touched. These oils are present even on dead leaves and can become airborne and inhaled if the plant is burned.

Seeds That Stick To Clothing: Different Types Of Hitchhiker Plants

Even now, they’re lingering along the roadside waiting for you to pick them up and take them wherever you’re going. Some will ride inside your car, others on the chassis and a few lucky ones will find their way into your clothing. Yes, weeds that spread by people, or hitchhiking, have certainly taken advantage of you this year. In fact, the average car carries two to four seeds for hitchhiker plants at any given time!

What are Hitchhiker Weeds?

Weed seeds spread in a variety of ways, whether traveling by water, by air, or on animals. The group of weeds nicknamed the “hitchhikers” are seeds that stick to clothing and fur, making it difficult to dislodge them immediately. Their variously barbed adaptations ensure that the seeds will travel far and wide via animal locomotion, and most can be eventually shaken off down the road somewhere.

Although it might sound like all fun and games, the weeds spread by people are not only difficult to contain, they’re costly for everyone. Farmers lose an estimated $7.4 billion each year in productivity to eradicate these pest plants. Humans are spreading these seeds at a rate of 500 million to one billion seeds a year in cars alone!

Although the weeds within crop stands are annoying, those that appear in fields can be downright dangerous for grazing animals like horses and cattle.

Types of Hitchhiker Plants

There are at least 600 weed species that travel by hitchhiking with humans or on machines, 248 of which are considered noxious or invasive plants in North America. They come from every kind of plant, from herbaceous annuals to woody shrubs, and occupy every corner of the world. A few plants you might be familiar with include the following:

  • “Stick-tight” Harpagonella (Harpagonella palmeri)
  • “Beggerticks” (Bidens) (Krameria grayi) (Tribulus terrestris) (Opuntia bigelovii) (Torilis arvensis) (Symphyotrichum lateriflorum) (Arctium minus) (Cynoglossum officinale) (Cenchrus)

You can help slow the spread of these hitchhikers by carefully inspecting your clothing and pets before emerging from a wild area full of seeding plants, making sure to leave those unwanted weeds behind. Also, reseeding disturbed areas like your garden plot with a cover crop can ensure that there’s too much competition for hitchhikers to thrive.

Once those weeds emerge, digging them out is the only cure. Make sure to get three to four inches (7.5 to 10 cm.) of root when the plant is young, or else it’ll grow back from root fragments. If your problem plant is already flowering or going to seed, you can clip it at the ground and carefully bag it for disposal – composting will not destroy many of these types of weeds.

Last, but not least, check your car any time you’ve been driving on unpaved roads or through muddy areas. Even if you don’t see any weed seeds, it wouldn’t hurt to clean your wheel wells, undercarriage and any other location where seeds might be hitching a ride.

What Weed Has a Round Prickly Seed Pod?

Datura, a night-blooming flower sometimes raised in home gardens, is also known as Jimsonweed or Thornapple (Datura stramonium). Jimsonweed is a contraction of Jamestown and is the name that early settlers and British soldiers gave the plants. Thornapple is an appropriate common name because it aptly describes the round, prickly seedpod that develop after the spent flowers fall off the plant. The prickly seedpods prevent animals from eating the toxic seeds.

Description

Jimsonweed grows to heights of between 1 and 5 feet. Its leaves’ edges are toothed edges and nearly egg shaped with pointed ends. Their length ranges from 2 to 8 inches. Funnel-shaped flowers are 2-1/2 to 4 inches long and open to a trumpetlike bell in white, violet or lavender. The plant’s fruit is a spiny pod measuring roughly 2 inches in diameter. The seedpods grow as they ripen and the seeds mature. Ripe seedpods burst open, scattering the seeds.

  • Jimsonweed grows to heights of between 1 and 5 feet.
  • Its leaves’ edges are toothed edges and nearly egg shaped with pointed ends.

Datura Species

Most species are low-growing, shrublike or spreading perennials or are prolifically reseeding annuals. D. wrightii is the species that is common to the Western United States. Rank-smelling leaves and large, white flowers that are occasionally tinged with purple characterize this plant. A sprawling perennial, the plants have enormous taproots that may extend deeper than 2 feet into the ground. Its geographic range extends from California to Utah, Arizona, New Mexico and into Texas. D. wrightii is considered a cosmopolitan annual weed that seeds prolifically. D. discolor is a native species found in riverbeds and desert washes in Arizona and southeastern California. It has smaller flowers. D, stramonium is naturalized throughout the United States. D. stramonium is distinguished from D. wrightii because the plants have smaller flowers and a more erect growing habit.

  • Most species are low-growing, shrublike or spreading perennials or are prolifically reseeding annuals.
  • D. discolor is a native species found in riverbeds and desert washes in Arizona and southeastern California.

History

The contraction of “Jamestown weed” is the origin of the name Jimsonweed. Soldiers and settlers were poisoned after eating the plant’s leaves in salads. Long ago in India and Russia, robbers would grind up the seeds of Jimsonweed and mix them with water as a way to sedate, induce amnesia or daze people they intended to victimize and rob. Members of the ancient Indian religious order that worshipped Kali, the goddess of destruction, would also grind the seeds and feed them to people before robbing and/ murdering them. In China, Jimsonweed was prescribed for the sedative effects, for foot diseases and used for flatulence.

Toxic Effects

All parts of Datura or Jimsonweed are poisonous. Keep places where livestock graze free of the plant. Ridding an area of plants is difficult and time consuming because of the ease with which seeds spread. Some people may experience skin irritation from contact with these plants, so wear protective clothing or gear. Symptoms of Jimsonweed poisoning include blurred vision, confusion, dilated pupils, dry mouth, difficulty urinating, hallucinations and tachycardia. Although it rarely causes death, later signs of toxicity may include coma and seizures. Emergency medical attention is necessary in cases of suspected Jimsonweed poisoning. Poisoning is treated with activated charcoal and gastric lavage. Severe sinus tachycardia is treated with beta-blockers.