Most Common Types of Weeds in Maine

Maine's lush landscapes are the perfect habitat for a wide range of plant species, including both beneficial plants and troublesome weeds. While some weeds may seem harmless, they can quickly overtake gardens, flower beds, and lawns if left unchecked. Whether you're a seasoned gardener or a beginner, understanding these noxious weeds in Maine is essential for maintaining a healthy and vibrant garden.

In this comprehensive guide, we'll delve into the most common weeds found in Maine, based on the Maine Department of Agriculture. By learning to identify these weeds and understanding their growth habits, homeowners can effectively combat their spread and maintain healthy outdoor spaces.

The most common types of weeds in Maine are:

1. Canada Thistle
2. Vetch
3. Morning Glory (Bindweed)
4. Purple Loosestrife
5. Creeping Charlie
6. Common Chickweed
7. Garlic Mustard
8. Hairy Galinsoga
9. Woodsorrel
10. Common Purslane
11. Sowthistle
12. Dandelion
13. Clover
14. Cypress Spurge
15. Yellow Nutsedge
16. Quackgrass
17. Crabgrass
18. Ragweed
19. Shepherd's Purse
20. Lampsquarters
21. Pigweed
22. Plantain
23. Asiatic Bittersweet
24. Poison Ivy
25. Giant Hogweed
26. Japanese Knotweed
27. Field Horsetail

Canada Thistle (Cirsium arvense)

• Identification: Canada Thistle is a perennial weed with spiny, lance-shaped leaves that have irregular lobes and sharp prickles along the margins. It produces clusters of small purple or pink flowers atop tall stems.
• Type: Perennial weed
• Habitat: Found in fields, pastures, roadsides, and disturbed areas.
• Growth Season: Grows throughout the summer months.
• Spread: Spreads via seeds and creeping underground rhizomes.
• Control: Hand-pulling or digging out the entire root system before flowering, repeated mowing, and targeted herbicide applications.

Vetch (Vicia spp.)

• Identification: Vetch is an annual or perennial vine with compound leaves and tendrils for climbing. It produces clusters of small, pea-like flowers ranging in color from purple to pink or white.
• Type: Annual or perennial vine
• Habitat: Often found in fields, meadows, and along roadsides.
• Growth Season: Grows vigorously in spring and early summer.
• Spread: Propagates by seeds.
• Control: Regular mowing before flowering, hand-pulling small infestations, and applying selective herbicides labeled for vetch control.

Morning Glory (Bindweed) (Convolvulus arvensis)

• Identification: Morning Glory, also known as Bindweed, is a creeping perennial vine with arrowhead-shaped leaves and white or pink trumpet-shaped flowers.
• Type: Perennial vine
• Habitat: Common in gardens, lawns, and disturbed areas.
• Growth Season: Grows throughout the summer.
• Spread: Spreads by seeds and creeping rhizomes.
• Control: Regular cultivation to disrupt root systems, hand-pulling, applying herbicides specifically targeting perennial weeds, and using mulch to smother growth.

Purple Loosestrife (Lythrum salicaria):

• Identification: Purple Loosestrife is a tall perennial plant with lance-shaped leaves arranged opposite each other on the stem. It produces spikes of magenta-colored flowers.
• Type: Perennial herb
• Habitat: Thrives in wetlands, ditches, and along waterways.
• Growth Season: Flowers from mid to late summer.
• Spread: Propagates through seeds and rhizomes.
• Control: Biological control using insects like Galerucella beetles, manual removal before flowering, and selective herbicide application in large infestations.

Creeping Charlie (Glechoma hederacea)

• Identification: Creeping Charlie, also known as Ground Ivy, is a low-growing perennial with rounded, scalloped leaves and small, tubular purple flowers.
• Type: Perennial herb
• Habitat: Found in shaded areas, lawns, and gardens.
• Growth Season: Grows year-round in mild climates but most vigorously in spring and fall.
• Spread: Spreads by seeds and creeping stems.
• Control: Regular mowing, hand-pulling, improving lawn health to outcompete Creeping Charlie, and targeted herbicide application.

Chickweed (Stellaria media)

• Identification: Chickweed is a low-growing annual with opposite, oval-shaped leaves and small white flowers with five deeply lobed petals.
• Type: Annual herb
• Habitat: Common in gardens, lawns, and disturbed areas.
• Growth Season: Thrives in cool, moist conditions during spring and fall.
• Spread: Spreads rapidly by seeds.
• Control: Hand-pulling, maintaining a thick, healthy lawn, and applying pre-emergent herbicides in early spring.

Garlic Mustard (Alliaria petiolata):

• Identification: Garlic Mustard is a biennial herb with heart-shaped leaves that emit a strong garlic odor when crushed. It produces clusters of small white flowers.
• Type: Biennial herb
• Habitat: Found in woodlands, disturbed areas, and along trails.
• Growth Season: Grows in spring and flowers in late spring to early summer.
• Spread: Spreads by seeds and forms dense colonies.
• Control: Hand-pulling before seed production, preventing seed dispersal, and using weed killers labeled for garlic mustard control.

Hairy Galinsoga (Galinsoga quadriradiata)

Identification: Hairy Galinsoga is an annual weed with hairy stems and leaves that form opposite pairs. It produces small, daisy-like flowers with yellow centers.

Type: Annual herb

Habitat: Common in gardens, fields, and disturbed areas.

Growth Season: Grows rapidly in warm weather.

Spread: Spreads by seeds and can quickly colonize bare soil.

Control: Hand-pulling, mulching to prevent seed germination, and applying post-emergent herbicides.

Woodsorrel (Oxalis spp.)

• Identification: Woodsorrel, also known as golden clover, is a perennial weed with clover-like leaves that fold up at night or during dry periods. It produces small yellow flowers with five petals.
• Type: Perennial herb
• Habitat: Found in lawns, gardens, and wooded areas.
• Growth Season: Grows year-round in mild climates but most actively in spring and fall.
• Spread: Spreads by seeds and creeping underground rhizomes.
• Control: Regular mowing, hand-pulling, improving soil drainage to discourage growth, and applying selective herbicides.

Common Purslane (Portulaca oleracea)

• Identification: Common Purslane is a succulent annual weed with fleshy, paddle-shaped leaves and small yellow flowers.
• Type: Annual herb
• Habitat: Thrives in sunny, dry areas such as gardens, lawns, and cracks in pavement.
• Growth Season: Grows throughout the summer.
• Spread: Spreads by seeds and stem fragments.
• Control: Hand-pulling before flowering, maintaining a thick turf, and applying pre-emergent herbicides in spring.

Sowthistle (Sonchus spp.)

• Identification: Sowthistle is a biennial or perennial weed with deeply lobed leaves and yellow flowers resembling dandelions.
• Type: Biennial or perennial herb
• Habitat: Common in disturbed areas, pastures, and roadsides.
• Growth Season: Grows year-round in mild climates but most actively in spring and fall.
• Spread: Spreads by seeds and creeping roots.
• Control: Hand-pulling, regular mowing, and applying post-emergent herbicides labeled for sowthistle control.

Dandelion (Taraxacum officinale)

• Identification: Dandelion is a perennial weed with deeply toothed, basal leaves and bright yellow composite flowers that mature into puffball-like seed heads.
• Type: Perennial herb
• Habitat: Found in lawns, gardens, fields, and disturbed areas.
• Growth Season: Grows year-round but most actively in spring and fall.
• Spread: Spreads by wind-dispersed seeds and taproots.
• Control: Hand-pulling, digging out the entire tap root, regular mowing, and applying selective herbicides targeting broadleaf weeds.

Clover (Trifolium spp.)

• Identification: Clover is a low-growing perennial with trifoliate leaves and small clusters of white, pink, or red flowers.
• Type: Perennial herb
• Habitat: Common in lawns, fields, and pastures.
• Growth Season: Grows vigorously in spring and summer.
• Spread: Spreads by seeds and creeping stems.
• Control: Hand-pulling, improving soil fertility to encourage grass competition, and applying weed killers labeled for clover control.

Cypress Spurge (Euphorbia cyparissias)

• Identification: Cypress Spurge is a low-growing perennial with narrow, blue-green leaves arranged spirally around the stem. It produces small yellow-green flowers.
• Type: Perennial herb
• Habitat: Thrives in dry, sandy soils, and rocky areas.
• Growth Season: Flowers in late spring to early summer.
• Spread: Spreads by seeds and rhizomes.
• Control: Hand-pulling, wearing gloves to prevent skin irritation, improving soil drainage, and applying pre-emergent herbicides in spring.

Yellow Nutsedge (Cyperus esculentus)

• Identification: Yellow Nutsedge, also known as nutgrass, is a perennial weed with triangular stems and grass-like leaves. It produces clusters of small yellow or brown flowers.
• Type: Perennial herb
• Habitat: Common in moist, poorly drained soils such as lawns, gardens, and wetlands.
• Growth Season: Grows rapidly in warm weather.
• Spread: Spreads by tubers and seeds.
• Control: Hand-pulling, removing tubers to prevent regrowth, improving soil drainage, and applying selective herbicides labeled for nutsedge control.

Quackgrass (Elymus repens)

• Identification: Quackgrass is a perennial grass weed with broad, flat leaves and upright flower spikes.
• Type: Perennial grass
• Habitat: Found in lawns, gardens, and disturbed areas.
• Growth Season: Grows vigorously in spring and summer.
• Spread: Spreads by seeds and creeping underground rhizomes.
• Control: Hand-pulling, digging out rhizomes, regular mowing, and applying post-emergent herbicides labeled for quackgrass control.

Crabgrass (Digitaria spp.)

• Identification: Crabgrass is an annual grass weed with spreading stems and wide, flat leaves that form a rosette. It produces branching flower spikes.
• Type: Annual grass
• Habitat: Common in lawns, gardens, and disturbed areas.
• Growth Season: Thrives in warm weather during spring and summer.
• Spread: Spreads by seeds and forms dense patches.
• Control: Maintaining a thick turf through proper watering and fertilization, hand-pulling young plants, and applying pre-emergent herbicides before seed germination.

Ragweed (Ambrosia spp.)

• Identification: Ragweed is an annual weed with deeply lobed leaves and inconspicuous green flowers that produce abundant pollen.
• Type: Annual herb
• Habitat: Found in fields, roadsides, and disturbed areas.
• Growth Season: Grows vigorously in late spring and summer.
• Spread: Spreads by wind-dispersed pollen and seeds.
• Control: Hand-pulling before flowering, wearing protective clothing to prevent pollen exposure, and applying pre-emergent herbicides in early spring.

Shepherd's Purse (Capsella bursa-pastoris)

• Identification: Shepherd's Purse is an annual weed with deeply lobed basal leaves and small white flowers that develop into heart-shaped seed pods.
• Type: Annual herb
• Habitat: Common in gardens, fields, and disturbed areas.
• Growth Season: Grows year-round but most actively in spring and fall.
• Spread: Spreads by seeds.
• Control: Hand-pulling before seed production, maintaining a thick turf, and applying pre-emergent herbicides in early spring.

Lambsquarters (Chenopodium album)

• Identification: Lambsquarters is an annual weed with diamond-shaped, toothed leaves covered in a powdery white coating. It produces small green flowers.
• Type: Annual herb
• Habitat: Found in gardens, fields, and waste areas.
• Growth Season: Grows rapidly in spring and summer.
• Spread: Spreads by seeds.
• Control: Hand-pulling before seed production, maintaining a thick turf, and applying pre-emergent herbicides in spring.

Pigweed (Amaranthus spp.)

• Identification: Pigweed is an annual weed with oval to diamond-shaped leaves and dense clusters of small green flowers.
• Type: Annual herb
• Habitat: Common in gardens, fields, and disturbed areas.
• Growth Season: Grows rapidly in warm weather.
• Spread: Spreads by seeds.
• Control: Hand-pulling before seed production, maintaining a thick turf, and applying pre-emergent herbicides in early spring.

Plantain (Plantago spp.)

• Identification: Plantain is a perennial weed with basal rosettes of broad, ribbed leaves and slender spikes of tiny greenish-white flowers.
• Type: Perennial herb
• Habitat: Found in lawns, gardens, and disturbed areas.
• Growth Season: Grows year-round but most actively in spring and fall.
• Spread: Spreads by seeds.
• Control: Hand-pulling before seed production, maintaining a thick turf, and applying post-emergent herbicides labeled for plantain control.

Asiatic Bittersweet (Celastrus orbiculatus)

• Identification: Asiatic Bittersweet is a woody vine with alternate, glossy leaves and yellow-orange berries.
• Type: Perennial vine
• Habitat: Found in forests, fields, and along roadsides.
• Growth Season: Grows vigorously in spring and summer.
• Spread: Spreads by seeds and forms dense thickets.
• Control: Cutting vines and applying herbicides directly to cut stems, repeated monitoring and removal to prevent re-establishment.

Poison Ivy (Toxicodendron radicans)

• Identification: Poison Ivy is a woody vine or shrub with compound leaves containing three leaflets. It produces white berries.
• Type: Perennial vine or shrub
• Habitat: Common in wooded areas, along trails, and in gardens.
• Growth Season: Grows year-round but most actively in spring and summer.
• Spread: Spreads by seeds and creeping rhizomes.
• Control: Avoid contact, wear protective clothing and gloves when handling, carefully dig out the entire root system, and apply herbicides specifically formulated for poison ivy control.

Giant Hogweed (Heracleum mantegazzianum)

• Identification: Giant Hogweed is a large perennial herb with deeply incised, palmate leaves and umbrella-like clusters of white flowers.
• Type: Perennial herb
• Habitat: Found in wetlands, along riverbanks, and in disturbed areas.
• Growth Season: Flowers in late spring to early summer.
• Spread: Spreads by seeds and can form dense colonies.
• Control: Contact professionals for removal due to its potential health hazards, wear protective clothing and gloves if handling, and apply herbicides under strict safety measures.

Japanese Knotweed (Reynoutria japonica)

• Identification: Japanese Knotweed is a tall perennial herb with bamboo-like stems and broad, heart-shaped leaves. It produces small white flowers in clusters.
• Type: Perennial herb
• Habitat: Common along riverbanks, roadsides, and in disturbed areas.
• Growth Season: Grows vigorously in spring and summer.
• Spread: Spreads by rhizomes and fragments.
• Control: Contact professionals for removal due to its aggressive growth, repeated cutting and herbicide applications, and strict disposal of plant material to prevent further spread.

Field Horsetail (Equisetum arvense)

• Identification: Field Horsetail is a perennial herb with jointed, hollow stems and whorls of slender, needle-like branches.
• Type: Perennial herb
• Habitat: Found in moist, sandy soils, and along riverbanks.
• Growth Season: Grows year-round but most actively in spring and summer.
• Spread: Spreads by spores and rhizomes.
• Control: Hand-pulling before spore production, improving soil drainage, and applying herbicides specifically labeled for horsetail control.

Targeted Weed Control

Identifying and managing common lawn weeds in Maine is essential for maintaining healthy and thriving landscapes. By understanding their characteristics, habitats, and growth habits, you can implement effective control measures and minimize the impact of these invasive weeds on your lawns. Regular monitoring, proper lawn care practices, and targeted herbicide applications can help you keep your outdoor spaces looking lush and vibrant year-round.

If you need help getting rid of weeds in your lawn, it might be time to call Allegro Lawn. With our targeted weed control program, our experienced technicians can help keep your grass weed-free year-round. Contact our team to set up a consultation today!