20 Common Weeds To Spot And Control

Crabgrass is a common annual weed found in lawns, gardens, and disturbed areas worldwide. It typically thrives in warm-season climates but can also appear in cooler regions during the summer months. It has flat, wide blades that radiate outward from a central point, resembling the shape of a crab.

Control tips: Applying pre-emergent herbicides before crabgrass seeds germinate can help prevent their growth. Post-emergent herbicides can be used to treat existing crabgrass plants, but they are most effective when applied while the weed is young and actively growing.

Dandelion, a widespread perennial weed, thrives in spring and summer but can persist year-round in temperate climates. Despite having multiple medicinal uses and being edible in salads, many homeowners prefer eliminating them due to their rapid spread and unattractive presence in well-kept landscapes.

Control tips: Cultural practices such as maintaining healthy turf through proper watering, mowing, and fertilization can help reduce dandelion infestations. Additionally, manual removal by digging out the entire root system or spot treatments with herbicides targeting broadleaf weeds can be effective.

Red Deadnettle is a common annual weed belonging to the mint family (Lamiaceae), native to Europe and Asia. It is recognized by its square stems, triangular leaves with serrated edges, and clusters of small, pinkish-purple flowers. This weed has some medicinal uses and is edible, with its young leaves occasionally added to salads.

Control tips: Regular maintenance of lawns or gardens and manual removal of small infestations are effective control methods. For larger areas, selective herbicides targeting broadleaf weeds can be used, applied during active growth periods for optimal efficacy.

Almost everyone is familiar with poison ivy and the well-known saying, "leaves of three, let it be." Poison ivy can reach up to 15 feet in height and width, growing as a vine, shrub, or ground cover in both sunny and shady areas. Avoid direct contact with this plant, as its oil can trigger severe allergic reactions.

Control tips: To prevent poison ivy, a thick layer of mulch can be applied. If spotted, it can be treated with herbicide or removed by carefully pulling it up using waterproof gloves or a plastic bag to protect the skin. Dispose of the plant and its roots properly by sealing them in a plastic bag and discarding them.

White Clover is characterized by its trifoliate leaves and clusters of small, white flowers that attract pollinators. It spreads through creeping stems, forming dense mats that can outcompete desired plants. Typically growing to around 8-10 inches tall and 12 inches wide, both red and white clover are nitrogen-fixing perennials.

Control tips: Mulch garden beds to prevent white clover from spreading in landscape areas. In lawns, an iron-based herbicide can effectively eliminate clover, or manually removing the weeds from garden beds is an option. Consider overseeding with competitive grass varieties to keep clover in check.

Oxalis, commonly known as wood sorrel, is a perennial weed that belongs to the Oxalidaceae family and comes in various species. Typically, it grows close to the ground, reaching heights of 6-12 inches, with shamrock-like leaves divided into three heart-shaped leaflets. Its delicate yellow flowers bloom throughout the growing season.

Control tips: Preventing the spread of this weed involves manual removal, ensuring to dig up the entire root system. Applying mulch can prevent its germination, and selective herbicides can be used for larger infestations, but caution should be exercised to avoid harming desirable plants.

Soliva sessilis, commonly known as lawn burrweed, is an annual weed that belongs to the Asteraceae family and is native to South America. It has low-growing stems with finely divided leaves forming rosettes near the ground. Its inconspicuous flowers develop into spiny burrs.

Control tips: Regular mowing can help prevent seed production while hand-pulling or hoeing can remove individual plants. Herbicides, both pre-emergent and post-emergent, may also be used to manage infestations, but care must be taken to follow label instructions and minimize harm to other plants.

This plant grows closely together, doesn't exceed 2 feet in height, and prefers dry, poor soil with abundant sunlight. It spreads readily through its creeping stems, featuring clover-like leaves and small yellow flowers. With a long taproot that extends deep into the ground, it can overtake weak grass as it rapidly spreads through its seeds.

Control tips: In lush, well-maintained lawns, it struggles to take hold. To keep black medic out of your garden, lay down mulch. Before it flowers and produces seeds, manually remove or dig out the weeds, especially when the soil is damp. Alternatively, you can use a post-emergent herbicide.

Commonly found in lawns, gardens, and shady areas, wild violet prefers moist, fertile soils and thrives in both sun and partial shade. This weed features heart-shaped leaves and attractive purple or blue flowers that bloom in spring. Despite its charming appearance, wild violet can be invasive, spreading via underground rhizomes and seeds.

Control tips: Managing wild violet involves regular hand-pulling, ensuring complete removal of the root system, and applying a broadleaf herbicide. Maintaining a dense, healthy lawn through proper mowing, fertilization, and watering can also help suppress its growth.

Black nightshade is an annual or short-lived perennial weed belonging to the Solanaceae family. This plant typically reaches 1 to 3 feet in height and features oval, dark green leaves with wavy edges. It produces small, white or pale purple flowers that give way to clusters of green berries, which turn black as they mature.

Control tips: Regular hand-pulling or hoeing, particularly when the soil is moist, to ensure the removal of the entire root system. Mulching can help prevent seed germination, and the use of pre-emergent and post-emergent herbicides may be necessary for larger infestations.

Plantain weed, also known as Plantago major thrives in compacted soil and can tolerate a range of soil types, from moist to dry conditions. This weed grows low to the ground, forming a rosette of broad, oval leaves with prominent veins. Small, inconspicuous greenish flowers grow on long, slender spikes.

Control tips: Pull or dig up plantain weeds regularly. Keep removing them before they have a chance to produce seeds. Over time, the plant will stop growing. It may feel like a never-ending task, but persistence is essential.

Nutsedge, or nutgrass, is a perennial weed from the Cyperaceae family, commonly found in lawns, gardens, and agricultural fields. It has a grass-like appearance, with triangular stems and narrow, V-shaped leaves. It produces small, yellowish-brown flowers and spreads through underground tubers called nutlets.

Control tips: Improve soil drainage and consistently remove plants by digging out the entire root system, ensuring nutlets are removed. Mulching can suppress its growth, and specific herbicides designed for nutsedge control can be applied for severe infestations.

Smartweed is a resilient annual or perennial weed from the Polygonaceae family that often invades lawns, gardens, and agricultural fields. It features lance-shaped leaves and small pink or white flowers arranged in dense clusters. This plant thrives in moist, nutrient-rich soil and can spread rapidly.

Control tips: Smartweed propagates via seeds. Remove the plant manually or use a post-emergent herbicide when it appears. To deter its growth, apply mulch to garden beds during the spring season.

Common ragweed can be easily recognized by its deeply divided leaves. It's important to be able to identify this weed, even if you're not concerned about having a perfectly manicured yard. For allergy sufferers, common ragweed is a significant cause of nasal allergies.

Control tips: Ragweed struggles to thrive in areas with frequent mowing or nutrient-rich soil. To prevent ragweed growth, maintain a well-fed lawn and regularly mow it. Removing ragweed plants by hand before they flower and produce seeds can prevent further spread.

Dayflower belongs to the same family as spiderwort plants (Tradescantia spp.). While it can create an attractive ground cover, it's deemed invasive in certain states. Eliminating it can be challenging since it withstands weed killers and regrows rapidly from broken stems. Its initial sprouts resemble healthy, broad-leaf grass, adding to the difficulty of identification.

Control tips: Apply mulch in the garden to hinder its germination, and consider using a pre-emergent herbicide during spring in areas where it's particularly problematic. Hand pulling or using a non-selective post-emergent herbicide are also effective control methods.

Galinsoga parviflora, commonly known as quickweed, is an annual weed belonging to the Asteraceae family. It typically grows up to 12-18 inches tall, featuring branching stems with opposite, serrated leaves. Its small daisy-like flowers come in white or yellow and bloom prolifically throughout the growing season.

Control tips: To deter the growth of quickweed, consider applying mulch or a pre-emergent herbicide during spring. These plants possess shallow roots and can be effortlessly removed manually or targeted with a post-emergent herbicide.

Lambsquarters is a rapidly growing annual broadleaf plant. Its seeds are small and light, easily carried by the wind over short distances. Remarkably, these seeds can endure in the soil for decades. It has scalloped, triangular leaves with gray undersides and grows erect, reaching heights of up to 4 feet.

Control tips: Regular cultivation can disrupt its growth while hand-pulling or hoeing can remove individual plants. Applying mulch can suppress germination, and pre-emergent herbicides can prevent new seedlings from establishing. In agricultural settings, post-emergent herbicides may be necessary for effective control.

Canada thistle is a vigorous perennial weed classified as a noxious plant in 43 states. It features whitish, creeping rootstocks that emerge during mid to late spring. Growing between 2 to 4 feet in height, it blooms with flowers appearing in July and August. Its propagation occurs through rhizomatous roots or seeds dispersed by the wind.

Control tips: Managing Canada thistle is challenging due to its extensive and deep root system, which facilitates its rapid recovery. Upon initial detection, promptly remove it using a hoe before it establishes strong roots. Additionally, applying herbicide treatments for approximately two years may be necessary to effectively eradicate this thistle.

Bahiagrass, a perennial warm-season grass, features vibrant green blades and spreads through rhizomes. Its distinct Y-shaped seedhead sets it apart. Thriving in poor soil conditions, Bahiagrass is also heat and drought-resistant, making it suitable for areas where other grasses struggle to grow. However, its resilience poses challenges when trying to control it as a weed in lawns.

Control tips: As the plant spreads through rhizomes, eliminating the rhizomes is essential to eradicating the grass. Small patches can be dug out manually, but for larger areas, using a post-emergent herbicide in late spring is necessary.

Barnyard grass is a summer annual that can grow up to 5 feet tall, although it typically stays around half that height. Its stems are thick, often with a maroon or reddish hue near the base, and they bear leaves approximately 6 inches long. Showy flowerheads or seedheads emerge at the top of the stem, often turning purplish as they mature.

Control tips: Hand pulling is generally effective in managing barnyard grass, especially if done before it goes to seed. In lawns, focus on maintaining healthy grass by ensuring proper fertilization, watering, and frequent mowing to prevent barnyard grass from seeding.