Lawn Pests & How to Control Them

Insects

Description and Trouble Signs

ANTS

ants

Several kinds may occur in lawns. They make nests underground. Around each entrance, a mound of soil particles may smother grass and make lawn unsightly.
Control: Most ants are beneficial and do not require control. Mounds can be washed or raked down then spot treated. Spraying a labeled insecticide 3 feet up and 3 feet out around a house perimeter will prevent them from coming inside.

Armyworms

armyworm

These pests are found in dense groupings, feeding on grass to make a somewhat circular area. The caterpillar is up to 1 ½ inches long with green, tan, or black stripes on its back. Damage occurs springtime through late summer.
Control: Liquid insecticides work well and do not mow for three days after application. Bacillus thuringiensis products work well on small caterpillars.

Billbugs

billbug

Adults are ¼ to ¾ inch long, black or reddish-brown beetles with long snouts. The chew holes in stems of grass, depositing eggs in them. Eggs hatch into chunky, legless, ½ inch long larvae, which puncture stem and crown as they feed. Kill grass in patches; grass blades break off at soil line.
Control: Treat with insecticides in early May before egg laying occurs. Beneficial nematodes can also be used.

Chinch Bugs

Chinch_Bug

Adults have black bodies with white and reddish legs. Nymphs grow from very small to 1/8 inch long adults. They prefer dry, sunny areas. Chinch bugs feed at all stages of their development, leaving large yellowish-to-brown patches.
Control: Avoid over-watering and fertilization. Preventative contact and systemic insecticides should control chinch bugs. Reapply if damage continues.

Cutworms

dingycutworm

Smooth grayish or brownish caterpillars, up to 2 inches long, feed at night after hiding under protective covering during the day. Cutworms can be a problem from spring to late summer.
Control: Apply liquid insecticide late in the day and when caterpillars are small. Best time is to make applications two to three weeks after a peak in moth flight activity.

Fiery Skippers

fiery_skipper

Distinguished by yellow, orange and brown butterflies that hover over the lawn during the hot part of the day. Eggs are deposited on grass and hatch into brownish yellow worms that feed and cause round 1 to 2 inch dead spots. A wide range of grasses is susceptible to the larval activity. These larvae chew grass foliage rather than roots.
Control: Reduce thatch and use Bacillus thuringiensis when caterpillars are small.

Grubs, White

grub

Grubs are the larvae of beetles, including Japanese and June. Larvae are thick, whitish, c-shape underground worms that vary from ¾ to 1 ½ inches in length. Grubs eat grass roots, leaving brown, dead patches easily lifted out of the lawn.
Control: Aerate well , water deeply, and avoid over-fertilization. Apply granular insecticide in early July.

Leafhoppers

Leafhopper

These yellow or green, slender, wedge-shaped insects are less than ½ inch long. Leafhoppers are especially active in lawns on the East and West coasts, but can be found throughout the country. They suck juices from leaves, causing grass to turn white, later yellow, then brown.
Control: Damage is usually insignificant to lawns but most insecticides will control them.

Mites

Dust Mites

Clover mites show us tiny red specks against white paper and are found in lawns nationwide. Bermuda grass mites are pale green and microscopic, occurring in Gulf Coast and Western lawns. The spidermites suck juices from grass leaves; grass wilts, turns yellow and dies. Mites shown here are greatly magnified.
Control: Maintain healthy lawns and provide adequate water.

Mole Crickets

Mole_cricket

A problem in Southern lawns. Brownish insects live in soil during the day and come out at night. These pests are about 1 ½ inches long. They cut off underground stems and roots in the day and work above ground stems
Control: Apply insecticides from April to May when mole cricket nymphs are small and easy to control. at night, leaving lawns with areas that appear closely clipped.

Nematodes

nematodes

Transparent round worms with whitish or yellowish tint are tiny, often microscopic. Their presence may not be realized until a bleached-out area is noticed. Lack of vigor and stunting of lawns may occur. The pests feed mainly on grass roots, but some on stem and leaves. Disease may set in because of weakened turf.
Control: Nematicides are not currently labeled for home lawn use.

Sod Webworms

sod webworm larvae

Tan-colored moths, about ¾ inch long, lay eggs at dusk. Gray or light brown larvae up to 1 inch long fed on bluegrasses and bent grasses, doing most damage during spring to midsummer. They feed on shoots and crowns of grass, causing irregular, close clipped brown patches.
Control: Apply contact or stomach poison insecticides early in the season when larvae are small. Apply at dusk right before the larvae feed.

Common Turf Diseases

Disease

Infection Sign and Controls

Anthracnose (Colletotrichum cereal)

AnthracnoseTurfgrass 2

Hosts: Creeping Bentgrass, Annual Bluegrass
Time: May-September
Anthracnose has two forms- foliar blight and basal rot. The foliar form develops as yellow/orange freckle-like spots or 1’ patches. Foliar blight starts on the tip of older leaves. The basal rot attacks leaf sheaths, crowns, and stolons. Black spiny fruiting structures can be seen with a hand lens. Low cutting heights, high traffic, malnutrition and lack of water increase severity.

Brown Patch (Rhizoctonia solani)

brown_patch

Hosts: Creeping Bentgrass, Kentucky Bluegrass, Fescues, Ryegrasses
Time: May-September
In taller cut grasses, rough circular patches that are brown/tan/yellow may be 6” to several feet. Tan lesions with a dark brown border are evident on leaves. During high humidity mycelia strands can be seen growing between leaves. Smoke ring can be seen on putting greens.

Large Patch (Rhizoctonia solani)

large_patch

Hosts: Bremudagrass, Centipede, Seashore Paspalum, St. Augustine, Zoysia
Time: August-May
Large patch is a new name for an old disease. Formerly known as brown patch, it was distinguished as separate because it affects warm-season grasses and occurs at different times of the year than brown patch on cool-season grasses. Large (2-10’) yellow/tan/straw colored and circular patches develop when temperatures are cool and moist. An orange ring can be seen on the edge of the patches. Leaf sheaths and crowns have lesions.

Dollar Spot (Scleroinia homeocarpa)

Dollar_Spot

Hosts: ALL
Time: February-November
Foliar blight starts on the tip of older leaves. The basal rot attacks leaf sheaths, crowns, and stolons. Black spiny fruiting structures can be seen with a hand lens. Low cutting heights, high traffic, malnutrition and lack of water increase severity.

Necrotic Ring Spot (Leptosphaeria korrea)

necrotic_ring_spot

Hosts: Kentucky Bluegrass, Fescues, Annual Bluegrass
Time: June-September
This is a perennial disease of KYB. Circular or doughnut-shaped patches of dead grass develop in late summer. Usually a problem on 3-year old sodded lawns that are growing on subsoil or a different soil type. The fungus attacks the roots and crowns. Recovery is often very slow.

Leaf Spot & Melting out (Drechslera poae, Bipolaris cynodontis)

leafspot

Hosts: Creeping Bentgrass, Annual Bluegrass
Time: Leaf Spot: March-June; Melting out: September-November
In KYB, this disease is active in warm/humid weather but in B it is active when it is cool/wet. Leaf spots are seen at the beginning of the disease cycle and this will lead to a melthing out of the individual sprigs. Lesions have a yellow halo. Dead plants form irregular patterns.

Pythium Blight (Pythium aphanidermatum)

phythiumblight

Hosts: Creeping Bentgrass, Kentucky Bluegrass, Fescues, Ryegrasses
Time: June-August
Small, sunken, circular patches up to 1’ in diameter are formed during hot/humid/wet weather. Leaves become matted, orange/gray and greasy looking. Mycelium can be seen growing from leaf to leaf. This disease moves quickly and often with water.

Red Thread (Laetisaria fuciformis)

redthread

Hosts: Kentucky Bluegrass, Fescues, Ryegrasses
Time: March-June
Circular to irregular patches develop. Cottony mycelium is usually visible. Red strands/threads grow from the affected leaves. Small tufts of pink fuzzy mycelium may also be seen during wet/humid weather.

Rust (Puccinia spp.)

rust

Hosts: Kentucky Bluegrass, Fescues, St. Augustine, Zoysia
Time: March-June and Sepetember-November
Early on small yellow flecks develop in stand. As the flecks turn into pustules that burst the orange spores are released often being apparent on white shoes. Clouds can be seen on heavily infested stands.

Spring Dead Spot (Ophiosphaerella korrae & O.herpotricha)

springdeadspot

Hosts: Creeping Bentgrass, Annual Bluegrass, Kentucky Bluegrass, Fescues
Time: June-September
In the summer, circular patches or rings appear (6” to 3’). Turf usually wilt, grow poorly and sink into patch eventually turning yellow then gray. Roots, crowns, rhizomes are black with mycelia. Remain active for years and grow outwards.

Summer Patch (Magnaporthe poae)

summerpatch

Hosts: Bermudagrass, Zoysia
Time: April-September
Circular patches develop in spring (6” to several feet). Roots, rhizomes and stolons usually are black from the fungus. Often less susceptible plants invade collapsed patch.

Take All (Gaeumannomyces graminis avenae)

takeall

Hosts: Creeping Bentgrass
Time: June-September
Circular, orange/tan patches appear in cool/wet springs. Droughty periods increase severity of patches in summer and fall. Alkaline soils (pH>7) favors this disease.

Common Weeds & How to Control Them

Weed

Description & Controls

Black Medic (Medicago lupulina)

Black_Magic

Low-growing annual or biennial with hairy stems. As with many weeds, gains foothold where grass is thin, especially in dry situations. Small, yellowish flowers usually appear from March to late fall.
Control: Thicken turf by feeding, mowing high, and watering to choke out weeds. A good cultural schedule is best defense against all weeds. Apply postemergence herbicide in early spring and again in fall.

Buttercup, Creeping (Ranunculus repens)

Creeping_Buttercup

Low-growing annual or biennial with hairy stems. As with many weeds, gains foothold where grass is thin, especially in dry situations. Small, yellowish flowers usually appear from March to late fall.
Control: Thicken turf by feeding, mowing high, and watering to choke out weeds. A good cultural schedule is best defense against all weeds. Apply postemergence herbicide in early spring and again in fall.

Carpetweed (Aizoaceae family)

Carpetweed

Found across the country. Easy to recognize-many narrow stems, small leaves, and tiny white flowers. Forms thick flat mat. Small greenish-white flowers bloom June to November. Self-seeding.
Control: Maintain a thick turf by following a good cultural schedule to choke out weeds. This pest can be killed with postemergence herbicide in spring or fall.

Chickweed, Common (Stellaria media)

chick_weed

An annual with delicate, creeping stem that tear easily when pulled. Tangled stems root readily under cool, moist, shady conditions. Found across the country. Produces tiny white, starlike flowers from February into December. Self-seeding.
Control: If small infestations, pull weeds early, before first seeds form. Use care to get all stems. For large area, apply postemergence herbicide in spring or fall. (Speedzone or Trimec)

Chickweed, Mouse-Ear (Cerastium vulgatum)

Mouse_Ear

A creeping perennial that forms dense matlike growth. Tiny white flowers appear from April into October. Prefers moist, cool conditions. Grows in most areas, especially in bright sunlight.
Control: Difficult to pull, because it entangles in the grass. Close mowing stimulates growth. Control by applying a postemergence herbicide. (Speedzone or Trimec)

Clover, white (Trifolium repens)

white_clover

A perennial readily recognized by typical cloverleaf shape and round white blooms. Spreads by creeping along and rooting in. Self-seeding. Leaves will stain clothing when bruised.
Control: Dig out clover as soon as it appears. For large area, use postemergence herbicide.

Crabgrass, Common (Digitaria sanguinails)

crabgrass

An annual bunch grass found across the country, except in the Southwest and in southern Florida. Blooms July to October. Doesn’t grow in shade- likes moisture and sun. Seeds mature in late summer and early fall.
Control: Follow a good cultural schedule to choke out pests. Mow lawn high during spring to shade germinating seedings. Apply a preemergence control in early spring.

Dandelion (Taraxacum officinale)

dandelion

Found across country except in a few areas of Deep South. Produces coarse-toothed, long leaves in bunch. Bright yellow blooms, followed by round, white seed heads. In cold areas, flowering occurs from March until a freeze; in warm areas, flowering occurs year-round.
Control: The entire taproot must be dug out; otherwise, a new plant will grow. Use a postemergence herbicide in the fall. Spot chemical applications are available.

Dock, curly (Rumex crispus)

Curly_Dock

A perennial with a 11/2 to 2-foot taproot. Produces one or more tall stems. Long, narrow leaves have curly edges and form a strong, tough rosette center. Found across the country. Seldom produces seed in well-maintained turf.
Control: If small infestation, dig out, being sure to get the entire root. On larger area, apply a postemergence herbicide. Apply spray into each plant crown.

Field Bindweed (Convolvulus arnensis)

bindweed

Shoots emerge from seeds and rhizomes. Cotyledons are kidney-shaped with a small notch in their tip. Alternate leaves are lobed at their base. Funnel-shaped flowers are white or pink.
Control:Time applications to coincide with maximum sugar movement to the roots (late summer or fall). Use systemic herbicides: 2,4-D, dicamba, picloram, dichlobenil, quinclorac, triclopyr.

Goosegrass (silver grabgrass) (Eleusine indica)

goosgrass

Prostrate growth habit, and is often white in the center with a wagon-wheel like appearance. Unlike crabgrass, it does not root at the nodes, but grows well in compacted soils.
Control:Germinates when soil temperatures reach 60 to 65 °F, and requires moisture and light for germination. Preemergence: pendimethalin, sulfentrazone, oxadiazon, dithiopyr, prodiamine. Postemergence: glyphosate, sethoxydim.

Ground Ivy (Glechoma hederacea)

ground ivy

Perennial with creeping stems, which root at the node. It forms dense patches and thrives in both sun and shade. The leaves are scalloped along the margin, heavily veined and rough on the upper surface. Funnel-shaped blue/violet flowers are found in clusters in leaf axils and occur in the spring.
Control: Apply when in bloom. Postemergent: clopyralid & triclopyr (Confront, Brazen), 2,4-D & triclopyr (4-Speed XT, Candor), glyphosate.

Henbit (Lamium amplexicaule)

henbit

Winter annual or biennial weed. Stems grow primarily upright but can root at the lower nodes. Leaves are rounded, coarsely toothed, hairy, and deeply veined. Flowers are in whorls in the axils of the upper leaves. Petals are purple and fused into a two-lipped tube
Control: Preemergent: Simazine, isoxaben, dithiopyr, oryzalin, pendimethalin, prodiamine.
Postemergent: glyphosate, 2,4-D & dicamba & mecoprop & sulfentrazone (Dismiss + Trimec Classic, Surge)

Pennywort (Hydrocotyle sibthorpioides)

Pennywort

A perennial that thrives in shady, moist areas in Southern California, from Massachusetts to Florida, and west to Indiana and Texas. Produces small, round, white flower heads July to October. Spreads by seeds and underground stems.
Control: Apply a postemergent herbicide during active growing period.

Plaintain, broadleaf (Plantago major)

plantain

A perennial (sometimes annual) with broad leaves, 3 to 6 inches long and bunched low. Tall, slender stalks bloom June to October. Spreads by seeds.
Control: If small infestation, dig out when soil is moist. For larger area, use a postemergence herbicide in early spring or fall.

Prostrate Spruge (Euphorbia humistrata)

spurge

Summer annual with a taproot; it has an open and prostrate mat-forming growth habit. Milky juice oozes from broken stems. Opposite leaves vary in different colors of green and with a maroon blotch. Flowers are small, pinkish-white, inconspicuous, and borne in the leaf axils.
Control: Preemergent: Oxadiazon, isoxaben, prodiamine, dithiopyr, oryzalin, pendimethalin.
Postemergent: Spurge Power, Surge, T-Zone, Speedzone, Q-4, Candor, glyphosate

Purslane (Portulaca oleracea)

purslane

Summer annual weed that can reach 8 inches in height. Leaves are thick and fleshy, arranged alternately on the stem, and low and spreading along the ground. Flowers are bright pink, and have five petals. Blooms in late spring and early fall.
Control: Postemergent: 2,4-D & carfentrazone & dicamba & mecoprop – Speedzone, Turflon Ester, Trimec

Quack grass or Couch grass (Agropyron repens)

Quack_grass

A vigorous-spreading perennial bunch grass. Forms a dense root structure by rooting at every joint on underground stems. Found across country except in parts of Southwest and Deep South.
Cannot be eradicated without killing lawn grasses, too.
Control: Leaf Spot: March-June; Melting out: September-November
In KYB, this disease is active in warm/humid weather but in B it is active when it is cool/wet. Leaf spots are seen at the beginning of the disease cycle and this will lead to a melthing out of the individual sprigs. Lesions have a yellow halo. Dead plants form irregular patterns.

Shepherd's-purse (Capsella bursapastoris)

Shepherds_purse

A persistent annual member of the mustard family that forms a circle of low leaves with white flowers consisting of four petals on tall stems. Seedpods are shaped like a shepherd’s purse.
Control: Fairly easy to pull if soil is moist. For larger area, use a postemergence herbicide.

Sorrel, red (Sheep sorrel) (Rumex acetosella)

Sorrel

A perennial that forms a matlike growth in early summer. Found whereever soil and drainage are poor. Spreads by underground stems and seeds. Yellow-green flowers appear on male plants; female plants bear reddish-brown flowers.
Control: Use a postemergence herbicide in early spring and early fall.

Thistle, Canada (Cirsium arvense)

Canada_Thistle

Thrives in clay soils in the North. Long prickly leaves and lavender flowers. Spreads by seed and underground roots. Blooms July through October.
Control:Use a knife to cut below ground to remove crown and roots. For larger infestation, apply a postemergence herbicide.

Yellow Nutsedge (Cyperus esculentus)

yellow_nutsedge

Rapidly spreading perennial that forms brown- to tan-colored tubers at the tips of rhizomes. Stem is triangular and you can feel it when you roll it between your fingers.
Control: Postemergent: Dismiss, Prosedge