Broadleaf Plantain

Plantago majo

Perennial, broadleaf

RANGE: Throughout the United States and southern Canada.

APPEARANCE: Broadleaf plantain has gray-green, egg-shaped, wavy-edged leaves growing in ground-hugging rosettes. Narrow seed heads appear in a long cluster on a central, upright stem.

GROWTH: Rosettes appear in mid-spring in thin and weakened turf. Seed stalks rise from early summer through September. The rosette has a tendency to suffocate desirable lawn grasses. Plantain grows from seed and re-sprouting roots. Seed germinates best in rich, moist, compacted soil.

Black Medic

Medicago lupulina

Annual, broadleaf (sometimes survives as a short-lived perennial).

RANGE: Throughout the United States.

APPEARANCE: With its three leaflet, clover like leaves, this legume is often confused with white clover. Low growing, with trailing, slightly hairy stems, it produces clusters of small, bright yellow flowers in late spring to early summer.

GROWTH: Black medic is common in lawns from May through September. It is especially prevalent in dry soils where turf is spotty and in high-phosphorus soils. Though an annual, it can be as persistent as a perennial.

Clover

Trifolium repens

Perennial

RANGE: Throughout the United States.

APPEARANCE: The leaves are compound, with 3 broad leaflets (sometimes 4, if you're lucky!) 1.3 - 2.5 cm long, with tiny teeth on the edges, a pale triangular mark appears on each leaflet.

GROWTH: Appear from May to September.

Crab Grass

Smooth and Hairy

Digitaria Ischaemum and D. Sanguinalis

Annual, grassy

RANGE: Throughout the United States.

APPEARANCE: Smooth and hairy crabgrass have a prostrate growth habit with coarse, light green blades. The blades are short, pointed, and hairy.

GROWTH: This vigorous, warm-season annual grass grows rapidly from early spring until seed heads form in late summer to early fall. It grows especially well in lawns that are watered lightly, under fertilized, poorly drained, and growing thinly. The plant spreads by seed, and to a lesser extent, by rooting from the lower swollen nodes of stems.

Curly Dock

Rumex crispus

Perennial, broadleaf

RANGE: Throughout the United States.

APPEARANCE: Bright, shiny green, lance-shaped leaves appear in spring. In summer and fall, the puckered wavy edges of the leaves are tinted reddish purple. Small greenish flowers appear on a tall, narrow spike coming from the center of the plant.

GROWTH: Growing from a large, brownish taproot, curly dock is a perennial weed that grows most actively when grass is suffering from the stress of hot, dry weather.

Dallis Grass

Paspalum dilatatum

Perennial, grassy

RANGE: Coastal states from New Jersey to California, and as far north as Missouri.

APPEARANCE: Coarse blades, somewhat upright in a bunch-type growth. Rhizomes are so closely jointed that they appear almost scaly. Stems 2 to 6 inches long emerge from the plant center in a star like pattern. Seed heads are sparsely branched on long stems. Seeds lie dormant over the winter and sprout very early in spring.

GROWTH: This is a summer weed in many areas of the country, but it grows throughout the year in mild climates, and thrives in those areas that are low and wet.

Dandelion

Taraxacum officinale

Perennial, broadleaf

RANGE: Throughout the United States.

APPEARANCE: Everyone recognizes the bright yellow flowers of dandelions; they appear in early spring and are followed by puffy seed heads. They arise from rosettes of lance-shaped leaves.

GROWTH: Dandelions emerge in early spring, with flowering commencing as early as April and continuing through summer and fall. The plants reproduce from a long taproot, and from seeds. Seedlings can germinate at any time throughout the growing season.

English Daisy

Bellis perennis

Perennial, broadleaf

RANGE: Northern half of the United States.

APPEARANCE: Leaves of this perennial vary from nearly smooth to hairy, and form an extremely dense cluster. The daisylike flowers growing on 2-inch stalks have bright yellow centers highlighted with white to pinkish outer rays.

GROWTH: English daisy has long since gone from an ornamental to a well-established and fast-growing lawn weed. It grows most rapidly in spring and fall and in all seasons on the West Coast if protected from drought and heat.

Ground Ivy

Glechoma hederaceae

Broadleaf

RANGE: Throughout the United States.

APPEARANCE: Also called creeping Charlie, is a common lawn weed problem. Lawns in shaded areas and often with poorly drained fertile soil are typical sites for ground ivy to develop into a major problem. This plant may form extensive patches as it creeps along the soil and can move into sun areas. Stems are square. Leaves are arranged opposite of each other along stems, and are round to somewhat kidney shaped with rounded, toothed margins. Crushed leaves have a minty odor. Ground ivy has small funnel-shaped purplish-blue flowers.

GROWTH: April To June.

Mouse-Ear Chickweed

Cerastium fontanum vulgare

Annual or perennial, broadleaf

RANGE: Throughout the United States.

APPEARANCE: The name of this weed offers a clue to its appearance. It has long, narrow, fleshy leaves that look fuzzy. Small, white flowers appear in late spring and early summer, followed by seed heads in mid summer.

GROWTH: This weed grows most actively during spring and early summer when it spreads by means of creeping stems that root at the nodes. It grows close to the ground and can withstand low mowing. It grows vigorously in moist, poorly drained, and shaded areas.

Oxalis

Oxalidaceae

Perennial

RANGE: Throughout the United States.

APPEARANCE: Has bright yellow flowers and green leaves. It grows upright. O. europaea (also called O. Oxalidaceae) is a perennial with seeds and rootstocks so that it sometimes appears to be a creeping vine. The leaves and stems are often purple or reddish.

Purslane

Portulaca oleracea

Annual, broadleaf

RANGE: Throughout the United States, especially troublesome east of the Mississippi River.

APPEARANCE: Sprawling, thick, fleshy stems with rubbery leaves. Tiny, yellow, five-pedaled flowers open when the sun is shining brightly. Cup-shaped seedpods produce many small, black seeds that may lie dormant in the soil for years. Seldom found in the spring when the lawn is treated for other weeds.

GROWTH: Thrives in hot, dry weather, spreading by sprawling stems. It's extremely troublesome in thin areas of the lawn or in new lawns seeded in summer.

Quack Grass

Agropyron repens

Perennial, grassy

RANGE: Throughout the United States except in the extreme South.

APPEARANCE:Quackgrass is characterized by light green to blue-green coarse blades that are rough on their upper surface. If not mowed, it can grow 5 feet or more in a single season. Narrow flower spikes rising from the plant resemble rye or wheat. The plant spreads by large, white rhizomes.

GROWTH: Quackgrass grows quickly in spring and fall. It is especially vigorous in thin, undernourished turf. Though it sometimes goes unnoticed in early spring, quackgrass becomes quite obvious as it turns brown in summer.

Speedwell

Veronica officinalis

Perennial or annual, broadleaf

RANGE: Eastern half of the northeastern United States, except in the extreme South.

APPEARANCE: There are several types of speedwell, all characterized by small, lobed, and numerous leaves, and by tiny white or purple flowers. The scallop-edged leaves are paired, growing opposite each other. Heart-shaped seed pods grow on the stems below the flowers.

GROWTH: Speedwells are among the earliest of lawn weeds to appear, greening up as early as late winter. Most are characterized by creeping stems that root at the nodes. Some show an erect growth habit as they mature. They all thrive in cool, moist soils where turf has thinned.

Spurge

Euphorbia esula

Perennial

RANGE: Throughout the United States.

APPEARANCE: 6 to 36 inches in height. Erect stems support linear, alternate, and apetiolate leaves of a bluish-green hue. The species exhibits yellow-green inflorescence on an umbel near the top of the stem. The yellow-green bracts are the most colorful and conspicuous part of the plant. A milky white sap (latex) is present in all parts of the plant, and aids in identification.

GROWTH: The plant occurs primarily in non-cropland habitats, including roadsides, prairies, savannas, and woodlands. It is tolerant of a wide range of habitats, from damp to very dry soils.

Tall Fescue

Festuca arundinacea

Cool Season Perennial

RANGE: Pacific Northwest to the southern states in low-lying pastures.

APPEARANCE: Tall fescue does produce short rhizomes but has a bunch-type growth habit - it spreads primarily by erect tillers. Individual tillers, or stems, terminate in an inflorescence, reach 3 to 4 feet in height, and have broad, dark green basal leaves. Leaf blades are glossy on the underside and serrated on the margins. The leaf sheath is smooth and the ligule is a short membrane.

GROWTH: The grass flowers in the spring and seed mature in early summer. Seed are 4 to 7 mm long, elliptic and awned.

Wild Violet

Viola Pratincola

Winter Perennial

RANGE: Throughout the United States.

APPEARANCE: Wild violet is a winter perennial, growing 2 - 5 inches tall. It can have a tap root or a fibrous root system, and also can produce rooting stolons and rhizomes. The leaves can vary but usually are heart shaped, on long petioles with scalloped to shallow rounded margins. The flowers of wild violet range from white to blue to purple. Wild violet flowers are pansy-like with three lower petals and two lateral petals on long single flower stalks.

GROWTH: Appear from March to June.

Yellow Nutsedge

Cyperus esculentus

Perennial, Grassy

RANGE: Throughout the United States. A related species, purple nutsedge, is especially prevalent in the Southeast.

APPEARANCE: Though it resembles a grass, yellow nutsedge is actually a sedge. Its coarse, light green leaves grow upright from triangular stems. Seed heads appear from July to October.

GROWTH: Reproduces mainly from underground tubers; however, they can reproduce by seeds and underground stems. Tubers store food and are drought tolerant. Yellow nutsedge grows vigorously in summer, especially under moist conditions; primarily troublesome in closely mowed lawns.