Weeds can carry disease, smother cultivated plants, or alter the appearance of the garden for the worse. No matter how carefully you prepare and maintain your garden, you will find yourself dealing with weeds.
A weed is described as a plant that spreads readily and grows in an area where it isn’t welcome. As an example, dandelions are cultivated as a food crop in the garden, so wouldn’t be a weed in that case. Gardeners who use copious amounts of chemicals to eliminate it would consider it a weed.
Weeds are also defined by their difficulty to control, a gardening strategy known as tolerance. Certain species of weeds, like creeping Charlie, are simple to get rid of, so they might not be considered a weed and left to grow. Kudzu and bindweed can be an ongoing and extreme challenge to remove and aren’t tolerated in any amount.
A majority of the plants on this list have edible uses but are considered weeds in North America.
Bermuda Grass
Bermuda grass (Cynodon dactylon) is a well-known and common foe for growers in warmer regions and a welcome lawn option in others. Native to tropical areas in Africa, people cultivate it as turfgrass in Zones 7-10, with a few cultivars growing down to Zone 5.
In temperate regions of North America, it has escaped cultivation or has been carried for miles by birds. When it emerges where it isn’t wanted, it can be extremely difficult to control. It spreads through thick stolons and rhizomes in sunny areas. The plant doesn’t tolerate shade.
Bindweed
Morning glory, also known as bindweed (Convolvulus arvensis) is a persistent and costly weed, responsible for ruining commercial crops each year. The plant twines up other plants, strangling them. What makes this weed particularly challenging is that it can grow deep roots over a dozen feet into the ground, and it can go dormant and survive without sunlight for years.
That means even if you pull the plants from your garden, if you don’t remove every bit of root, it will likely return. That means you can’t use tilling to control this weed.
The small pink or white flowers open in the morning and close in the evening, mimicking the behavior of ornamental morning glory species.
Regular hand pulling or applying glyphosate are the best control methods.
Bittersweet
Oriental or Chinese bittersweet (Celastrus orbiculatus) was brought to North America as an ornamental, but it has since escaped cultivation and has become a problem across the continent.
Look for a vine with glossy green leaves that are round and finely toothed. In the spring, yellow flowers form, followed by berries filled with seeds.
It’s considered invasive in the Northeast and Midwestern states, and it’s also toxic to humans and animals. The plant is difficult to control because once birds eat the seeds, they can fly and spread the seeds for miles around. The plant also spreads by tough, invasive roots.
Your best chance at controlling this vine, which can grow up to 100 feet long, is to pull it when it’s young.
If the vine is already established, wait until the spring or summer and saw off a large part of the vine near the base. Spray and wipe the plant with glyphosate to kill it. As the plant starts to die, pull it out of the ground and away from any trees that it is growing on.
Note that closely related American bittersweet (C. scandens) is a valuable native that should be preserved. The stems on this plant are smooth rather than hairy, and the berries only grow on the tips of the leaves.
Black Medic
Black medic (Medicago lupulina) is considered invasive in parts of North America. Closely related to clover, it has a similar appearance but grows much taller, up to 32 inches tall. It has three leaflets and yellow blossoms.
Indigenous to Eurasia, it has naturalized across North America and Hawai’i. It readily establishes itself in any disturbed soil, whether it’s moist or dry, hard or loose. Since it fixes nitrogen, it’s also used as fodder and in folk medicine.
The plant has a long taproot, so it must be carefully pulled with a taproot tool, or poisoned using herbicides.
Chickweed
Native to Eurasia, chickweed (Stellaria media) has naturalized across the globe, where it grows in gardens, fields, and disturbed areas. The leaves are edible and full of nutrients, so the plant is occassionally cultivated as animal feed or a salad green. The plant contains saponins, so those who are sensitive should avoid it.
The small white flowers quickly transition to seed capsules, which are then dispersed to start new patches of weeds. Each plant can produce 800 or so seeds each year, meaning that it can rapidly take over an area.
Chickweeds grow in prostate mats and prefers moist areas, though they can tolerate short periods of drought.
Hand pull or till the plants before they set seed for best control.
Clover
Clover is increasingly being considered a welcome part of the garden rather than an invader, but it is still considered a weed when it appears where it isn’t wanted.
When people talk about “clover,” they’re referencing several different plants, all of which have three (or four or five) heart-shaped leaves.
White clover (Trifolium repens) is the most common invader of lawns and gardens across North America, but you might also encounter red clover (T. pratense) or wood sorrel (Oxalis spp.) species.
Regardless, they are all edible in small amounts, and they are all easily controlled. These aren’t plants with an aggressive growth habit.
Mowing high, broadleaf herbicides, and hand pulling (or a combination of all three) all work well.
Crabgrass
If you want to strike fear into the heart of a gardener, mention crabgrass (Digitaria spp.). This common weed looks like turfgrass, but it grows low to the ground and more sparse than turfgrass, making it an ugly element in the garden. It also rapidly spreads out of bounds, filling in anywhere the seeds can reach. You’ll find it growing in sidewalk cracks, disturbed soil, and among cultivated plants.
Because this annual plant spreads solely by seed, if you consistently remove it before it forms seedheads, you have a chance of getting rid of it.
Creeping Charlie
An invasive groundcover that easily outcompetes native plants or more tender annuals, creeping Charlie (Glechoma hederacea) is found throughout North America. The plant is closely related to mint and spreads in a similar manner, through creeping stolons and seeds.
The plant was brought from Europe with the intention to use it as a sturdy groundcover for shaded areas, but it escaped cultivation and can be found in disturbed areas like gardens, fields, and forests.
The bright green leaves of this plant are round or kidney-shaped and have a scalloped edge. The small flowers are purple on square stems, a defining characteristic of the family. It has a faint mint scent.
To remove the weed, you can alter the conditions to make them less hospitable to creeping Charlie. For instance, pruning a tree to improve sun exposure and dry the soil out will kill the plant. Hand removal is best if you can’t alter the growing conditions.
Curly Dock
Rumex crispus, commonly called curly dock, is a common sight in disturbed areas with lots of moisture for at least part of the year. The broadleaf perennials grow up to five feet tall and often grow among cultivated grasses like alfalfa and oats.
From the base of wide leaves with curly margins emerges a tall seedhead, which starts out as green and matures to a dark brownish-red hue in late summer.
A relative of buckwheat, the mature seedheads can be ground and used as a flour substitute. However, if you don’t intend to use this plant, it’s best to dig it up with a taproot weeder before the plant sets seeds. Once the seeds are mature, they will be dispersed in water and wind and can further spread the plant.
Dandelion
Cheerful dandelions (Taraxacum officinale) grow just about everywhere in North America. Most people are aware that the leaves are edible, and high-end grocery stores carry the leaves as a salad green option.
The entire plant is edible, including the roots, which are used as a coffee substitute. The plant is also valued for medicinal use.
To eliminate it, you must dig up the entire root, or the plant will be able to regenerate.
Dwarf Mallow
Dwarf mallow (Malva neglecta) is also known as cheese wheel for the small fruit that form. These look like tiny cheese wheels and are edible, though they don’t taste like cheese. Its large, round leaves are easily recognizable.
Related to marshmallow plants (Althaea officinalis), the entire plant is edible and some people allow it to grow where it has naturalized. Because it is mucilaginous, it can be used to thicken soups. It can also be used medicinally as a demulcent.
The plant is tough to pull once it becomes established, so controlling it is best done when the plant is young. Once the plant is older, you will need to dig down deep to release the large taproot. Herbicides are also effective, though indiscriminate, so they might damage desirable plants.
Garlic Mustard
Garlic mustard (Alliaria petiolata) is a dreaded weed. Localities require that people clean their shoes before entering nature conservancies to avoid spreading the seeds of this plant. That’s how easily it can hitch a ride and land in new places. Animals, humans, and tools all move the seeds from one area to another.
The plant was traditionally used as an edible and a medicinal, but it escaped cultivation when it was brought here to the US from Europe. The plant is in the mustard family, but it has a strong garlic scent and taste.
When it establishes itself in an area, it spreads rapidly and aggressively, crowding out native species and filling entire fields. Because it thrives in shade, it can quickly push out the more tender species that fill the forest floor.
Getting rid of this plant isn’t impossible, but it takes dedication. You’ll need to hand-pull the plant regularly. Do this before it seeds.
Ground Ivy
Ground-ivy (Glechoma hederacea) can make a garden look shabby and is considered an invasive pest in temperate parts of North America. It out-competes native plants in forest areas and is difficult to control because it has an extensive, strong root system, and using broad-spectrum herbicides can decimate native plants while attempting to eradicate it.
Also known as creeping Charlie or catsfoot, this mint-family plant isn’t as flavorful as traditional mint (Mentha spp.), but it’s completely edible, which is another tick in the positive column for this herbaceous plant.
Native to Europe, it was originally cultivated as a salad green and brought to North America as an edible and ornamental plant.
Hogweed
Giant hogweed (Heracleum mantegazzianum) is massive, invasive, and incredibly toxic. Even brushing against the plant and exposing the area to sunlight can cause the skin to develop painful burns and blisters that can cause permanent scarring.
This plant is in the carrot family and has the same white umbels of flowers that many of the plants in this family have. The flowers are huge, up to five feet wide, and deeply lobed.
The stem is yellowish-green to purple and hairless.
Because it’s so dangerous to come in contact with, extreme care should be used when removing it. Removal involves cutting off any seedheads before they mature and chopping the plant off at the base. This will require repeated efforts, but will eventually deprive the roots of nutrients, and the plant will die. Always wear protective clothing, including long sleeves, gloves, masks, and eye protection when working with this plant.
Horsetail
Horsetail weeds (Equisetum spp.), also known as scouring rush or snakeweed, are a fern relative that grows across North America. It’s considered a living fossil, though that probably won’t make you feel better when it’s popping up unwelcome in fields, roadsides, and other disturbed areas.
Depending on the species, horsetails can thrive in dry patches to swampy areas in full sun to partial shade. Horsetail species can grow up to 25 feet tall. Most species remain under a few feet tall.
A single patch can spread via spores up to 20 inches per year, so you can see how one plant can rapidly become an issue.
Herbicides aren’t effective, so your best bet at controlling it is to hand pull, till, or mow the plants regularly.
Japanese Knotweed
Japanese knotweed (Fallopia japonica syn. Polygonum cuspidatum ) is a serious problem in southern states, and the plant is listed as invasive by the US Department of Agriculture.
This vine in the buckwheat family was brought from Asia to North America in the 19th century to provide erosion control and ornamental value. Within a few decades, people were ripping it out of their gardens, and governments were recognizing its invasive potential.
It smothers out native plants and is found in 42 of the states in the US, with the arid Southwestern states spared.
The plant can spread via seeds that are carried by animals, wind, or water. It can also spread via rhizomes or stem fragments. Once it takes hold, it can be extremely difficult to control.
Jewelweed
It’s right in the name: jewelweed (Impatiens capensis) is both a beautiful jewel-like plant and a weed. If you’ve ever grown impatiens, they are closely related.
Also known as spotted touch-me-not, this plant grows everywhere in North America except for the dry, hot Southwest. Otherwise, it’s common in moist, shady areas.
The herbaceous plant has a prominent flower in yellow, orange, and reddish hues and was valued by indigenous tribes as a medicinal that could ease skin irritation and pain.
People encourage the cultivation of this plant despite the fact that it’s not as showy as its impatiens cousin. But it can be intrusive in areas, warranting control. To remove it, pull the plants before they begin to flower.
Kudzu
Kudzu (Pueraria montana var. lobata) is called the mile-a-minute plant because that’s how fast it seemingly grows. In actuality, it can grow a foot each day and will rapidly devour an area.
The vine is completely edible, including the root, but it is taking over parts of the United States so rapidly that we’d have to eat a lot to keep it in check. It’s considered invasive by the USDA and major efforts are underway to eliminate it.
The vines can grow up to 100 feet long and spread through runners. There are areas in the South that have been covered in vines, collapsing houses, and smothering every other plant species. They can even strangle large trees. As climate change warms the planet, the vine is finding its way into more areas than ever before.
Young patches can be pulled, but once an area becomes more established, you’ll need to trim, mow, cut, or even use goats and sheep to devour the plants. This takes persistence and dedication. Even allowing the vine to go for several months could result in a patch that has tripled or quadrupled in size.
Lambsquarters
Lambsquarters or goosefoot (Chenopodium album), so named for the goose foot-like shape of the grayish-green leaves, is common across North America. It’s part of the Amaranthaceae family, which also includes beets, amaranth, and quinoa.
As you might imagine, this plant is edible and a favorite of foragers, but a hated weed of gardeners. The leaves taste like mild spinach and can be eaten raw or cooked.
It pops up in gardens and fields and has naturalized in forests and meadows. It’s adaptable enough to survive in sunny or shaded spots, and the thousands of seeds that form on long stems are the reason why this plant is so successful.
The weed is easily controlled by mowing it down before it goes to seed. Once the plant goes to seed, you can be sure you’ll be finding it throughout the rest of your garden.
Madder
Madder (Sherardia arvensis), also known as field madder, looks similar to sweet woodruff (Galium odoratum) or bedstraw (Galium aparine), with its clasping leaves in whorls of four to six.
In the summer, pale pink or lavender flowers extend from the stems. These eventually turn to seeds which help the plant spread.
Indigenous to Europe, it has naturalized across North America and fills in garden beds, lawns, and disturbed areas.
A deep layer of mulch and hand cultivation can easily control this weed, which isn’t as aggressive as other weeds. If you find it growing in your lawn, pull the weeds and take steps to increase the health of your lawn, since this plant only grows in turfgrass that is thin. Increasing sunlight and adding fertilizer is usually enough to smother out this weed.
Nightshade
Black nightshade (Solanum nigrum) is often confused with deadly nightshade (Atropa belladonna), but the plants are very different despite looking similar. Deadly nightshade doesn’t grow in the majority of North America, while black nightshade is common across the continent.
Black nightshade is edible and consumed across the globe. It’s cultivated in Africa, South, and North America among certain communities. But in the majority of North America, it’s ruthlessly removed, often because people are concerned that it’s the highly toxic deadly nightshade.
It’s native to Eurasia and has been introduced to Africa, North, and South America. It grows in wooded areas, gardens, and disturbed areas and is usually identified by the nearly black berries that grow in clusters. The leaves bear a resemblance to tomatoes, to which they are closely related. The berries can be eaten when ripe.
The plants can easily be pulled by hand, and the plant rarely takes over an area unless left undisturbed for years.
Nutgrass
Purple nutsedge or nutgrass (Cyperus rotundus) aren’t actually nuts. It’s named for the tubers that resemble nuts. The plant is native to southern Europe and Africa, but it has spread into North and South America.
It has long, narrow leaves and tall stems topped with flower heads followed by seeds.
This noxious weed is in the sedge family and can quickly overgrow turfgrass in moist areas. Improving drainage and reducing water can sometimes help reduce this plant’s vigor. You should also pull or poison it before it goes to seed.
Pigweed
Part of the Amaranthaceae family, pigweed (Amaranthus retroflexus) is only a weed depending on where it is growing. It’s cultivated in places like Mexico and Jamaica for its flavorful seeds, leaves, and flowers. In most of the US, it’s an annoying weed that gardeners battle against year after year.
The elliptical leaves grow on long stems with branches full of seeds emerging near the top.
As with other plants in the amaranth family, removing this weed from your garden involves mowing down the plant before it seeds. If you do this regularly, it will eventually be eliminated.
Plantain
Plantago major, known as broadleaf plantain, is a common weed across North America, though it is native to Eurasia. Foragers appreciate it when they come across this plant as the leaves make a nutritious addition to the dinner table.
The plants grow in disturbed areas, lawns, fields, and other areas that have hard, depleted soil. It’s often one of the first plants to inhabit disturbed sites with its rosettes of broad, green leaves. In the summer and fall, the plant puts out tall stalks of seeds that can disperse on the wind.
The seeds can also hitch a ride in cereal crops, which has enabled it to spread to all corners of the globe.
Poison Ivy
There are two species of poison ivy: western poison ivy (Toxicodendron rydbergii) and eastern poison ivy (T. radicans). Western inhabits the area west of the Rocky Mountains, and eastern can be found east of the Rockies. They look similar and grow in similar conditions.
As with poison oak and poison sumac, the plant contains urushiol, which gives people a painful, persistent rash. Individuals can be immune to the effects, or they might need repeated exposures before they will show symptoms. A small percentage of individuals have allergies to it, so reactions will vary.
Removing the vine or shrub requires caution and protective clothing.
Poison Sumac
If you stumble across a patch of cinnamon ferns in the wild, be on the lookout for poison sumac (Toxicodendron vernix). The two often grow near each other, and while a fern might be a welcome sight, poison sumac isn’t.
If you touch it, your skin will break out in a painful rash thanks to the urushiol contained in the plant. Poison oak and poison ivy also contain this powerful compound. The plant can also damage your lungs if it is burned. That’s why most people try to keep it far away from their property.
Poison sumac is native to eastern North America, but it has spread as far east as the Rocky Mountains.
Poison Oak
Closely related to poison ivy and poison sumac, poison oak (Toxicodendron pubescens) contains the same toxic compound urushiol that causes a burning, persistent rash.
This plant grows in southeastern North America from the east coast to Texas and as far north as upper Oklahoma. Sensitive individuals may find themselves covered in painful sores after brushing up against the plant.
Resist the urge to scratch the rash if you develop one. Once the rash breaks open, it can invite infection.
Pokeweed
Pokeweed (Phytolacca americana) is native to eastern North America, but it’s an unwelcome weed across the continent and in parts of Europe and Asia. That’s because it’s highly toxic and kills livestock that eat it unintentionally every year. It’s also toxic to humans and pets.
Bird populations appreciate the plant, however. It’s an important source of food for mockingbirds, cardinals, and catbirds.
The plant can be prepared and eaten in early spring, but later in the year, it becomes incredibly toxic. It’s also used as a medicine. But for most people, it’s a nuisance that needs to be removed.
The good news is that the plant can only reproduce by seed, which are held in the glossy black drupes. That means you can remove it from your garden readily by hand pulling plants before the fruits form.
Purslane
Common purslane (Portulaca oleracea) is primarily treated as weed, though it is cultivate as an herb. The plant is high in omega-3 fatty acids as well as several important vitamins and minerals, so it has been gaining popularity as a food source.
Native to Africa, the Middle East, and India, it has naturalized across the globe and favors gardens, fields, roadsides, and other disturbed areas.
The fleshy leaves are oval and stand out against red stems. The stems primarily grow prostrate against the ground, but it can take on a more upright habit in moist environments. If the plants receive enough moisture, they will produce yellow flowers.
Hand pulling before the flowers fade and the seeds form is the easiest way to control purslane.
Ragweed
Notorious for causing untold suffering when it’s in bloom, ragweeds are plants in the Ambrosia genus that have naturalized across the warmer parts of North America. The leaves have a ragged appearance, hence the name, and the plants thrive in arid disturbed areas where other species struggle.
Each plant can produce billions of pollen grains, which can cause severe rhinitis in susceptible individuals. It can also cause dermatitis if you brush up against it.
Digging up the plant isn’t effective, so most people recommend herbicides and regular mowing.
Shepherd’s Purse
Shepherd’s purse (Capsella bursa-pastoris) is one of the most common plants in the world and has naturalized pretty much everywhere except Antarctica. It’s particularly aggressive in cool climates like the British Isles and the Pacific Northwest.
Part of the mustard family, it produces hundreds of tiny seeds that allow it to spread aggressively throughout disturbed areas like fields, gardens, and pastures.
Named for its fruits, which resemble the traditional pouch used by sheep herders, it’s valued by foragers as a nutritious green and medicinal plant. It’s cultivated in parts of Asia and used as a wonton filling, in the Korean dish namul, and in traditional Japanese dishes.
But if it’s growing where you don’t want it, hand-pull the plants before they seed. The roots, which are also used in cooking, are quite large, so you might want to use a trowel to help lift the roots out of the ground.
Spurge
Spurge is the name used for plants in the Euphorbia genus, but we’re talking specifically about E. maculata.
Spotted or prostrate spurge, as it’s known, is indigenous to North America, but it makes itself a nuisance by spreading throughout lawns and gardens. It prefers dry, hot areas and spreads rapidly.
As you might guess from its names, it grows along the ground, rarely growing more than a few inches tall, and the small green leaves have a single reddish spot on them. As the plant matures, small seeds develop along the stems.
Inside the stems is a sap that can cause mild dermatitis in sensitive individuals. The best method of control for this plant is to pull them by hand before they set seeds.
Stinging Nettle
Another weed that has gained a following for its nutritious elements, stinging nettle (Urtica dioica) can grow up to seven feet tall and is covered in hairy leaves. It’s not the hairs on the leaves and stems that earned the plant its name, but defensive hairs called trichomes that grow among the hairs that cause the burning, stinging sensation when you brush up against them.
Young leaves can be boiled and eaten, and taste similar to spinach.
Stinging nettle is native to Europe but has naturalized in all parts of North America and is particularly prevalent in areas with high rainfall, such as the Pacific Northwest.
Since contact with any part of the plant can be extremely painful, it’s best to wear protective clothing and gloves when pulling the weeds from the garden.
Thistle
Most people can instantly recognize thistles, especially if they’re pulling the vicious prickles out of their skin. The plants have white, ink, or purple blossoms and sharp needles on the leaves. When the flowers mature, they form downy white pappus that disperses far and wide in the wind.
Thistles don’t belong to any single botanical family, though most of them are in the Asteraceae family.
A majority of the species are edible, though you should stick to the stem and avoid the spiny needles and flowers. Most have deep rhizomes, making it difficult to completely remove the root system.
