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Signs and symptoms of trouble.

weedy lawn grasses

Poor lawn growing conditions enhance weeds, pest insects and turfgrass diseases.

Whether you have brown patches, bare spots or just too many weeds, many lawn problems are fueled by poor environmental conditions with soil, water and sunlight. Correcting those problems is the key to sustainable lawn care. Moisture and shade issues can be adjusted to favor grass. Soils in poor condition can be amended and revitalized to grow healthy, dense lawns that crowd out weeds and tolerate insects and disease.

Fixing conditions that favor pests over your lawn is a long-term strategy for creating a more sustainable yard—one that needs fewer inputs of water, fertilizer, pesticides, and precious time.

Common signs of lawn problems on this page:

Patches of Dead Grass

Dog spot, or spots where dogs pee—especially in hot dry weather—tend to burn out and kill grasses. In cooler, wet weather dog urine may cause a burst of top growth. Either way, the lawn can become ugly and patchy. Consider creating a low visibility area for dogs to pee or watering the area soon after to dilute the urine. Walk your dog along a road or to the park. Keep in mind healthy grass will tolerate some urine.

Two pictures of brown lawn grass surrounded by healthy grass
Patches of dead grass can have many causes. Dog spot (left) and winter weeds (right).
Tall dark patches of grass along a curb
Spring overgrowth caused by dog urine.

Weeds

Lesser celandine - a yellow flowering weed - in a lawn
Weeds like lesser celandine grow early and disappear by May, crowding turfgrasses and then leaving room for other weeds when they are gone.

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Lumpy Tunnels or Dug-up Grass

mole and vole damage in a lawn
Vole trails and mole mounds can seriously damage lawns.

You might have moles tunneling through the root zone or opossums, skunks or raccoons digging up grubs. See our Wildlife Identification and Management page for more information.

Salt and Compaction

Road and sidewalk salt can cause burnout in lawn edges and serious injury to landscape plants. While there isn't much you can do about road salt applied by your city or town, there are things you can do to lessen your chance of causing injury.

Compacted soil – Soil can become compressed into a hard impenetrable mass that dries quickly, feels like cement and does not grow grass. Aeration fixes compacted soils and helps you work in amendments that improve soil. The Cornell Turfgrass Team explains soil compaction and aeration here.

Bare, dry soil along a sidewalk with patchy grass nearby
Salt damage and compaction

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Grubs

White grub damage is not as intense a problem on home lawns as it is for athletic fields and golf course fairways. But grubs, which feed on the roots of lawn grasses, can cause dieback and areas of brown or dead grasses. Many wild animals, including opossums, skunks and crows, look for grubs to eat and may tear up parts of a lawn to get them. Pro Tip: You can combat lawn grubs using nature's own weapons! See Biocontrol Around the Home: Nematodes for White Grubs

a white grub in soil
White grub

Disease

Turfgrass diseases are most common on high maintenance grass, like a golf course. High maintenance golf grasses are often cut very short, suffer high foot traffic and build up disease organisms that routinely affect them. Lawn grasses are usually mowed higher, less stressed and don’t often have disease issues that require control. Some common turfgrass diseases are described on the Turfgrass Disease page and the Cornell Plant Disease Diagnostic Clinic.

close up of grass blades with patches of disease
Dollar spot disease on turfgrass blades.

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Dormancy or Drought

Drought – When hot, dry summer weather arrives, it is natural for grasses to dry up. Letting your lawn go dormant is a sustainable practice. Lawns can go dormant for six weeks without dying, but it’s not for everyone. If you plan to keep it green all summer, water 1” a week, including rainfall. Raise the height of your mower blades and sharpen them after 10 hours of use to get a clean cut on the blades of grass and reduce water loss. Click here to find good watering advice from Cornell Cooperative Extension of Suffolk County.

patchy dead grass
Heat stressed lawn
Large area of brown grass due to drought
Dormant lawn due to drought. Brian Kunkel, University of Delaware, bugwood.org

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Acidity or Alkalinity of Soil

The soil pH is off – The pH of any substance is the level of acidity or alkalinity of that substance. Most plants grow well in soil that is between 6.5 to 7.5 pH, which is very close to neutral (7.0). Extremes in soil acidity or alkalinity create poor growth and other problems, but some plants like a more acidic soil, including pines, rhododendrons and blueberries. Here is a Cornell Cooperative Extension guide to correcting soil pH.

Too Shady or Wet

Too much shade - Consider whether the area of poor growth is too shady for typical lawn grass. If the area receives less than 6 hours of direct sunlight you can still have a beautiful lawn with the right grass seed. Sun & Shade grass seed mixes will provide shade-tolerant varieties. Fine fescues (Red, Chewings, Hard fescues) are among the most shade-tolerant grasses available. Tall fescue is also shade and drought tolerant. Consider ways to trim and thin shade-causing trees and shrubs to allow more light to penetrate. See Pennsylvania State University's page Growing Turf Under Shaded Conditions for excellent guidance. Also consider alternatives to grass if shade will continue to be an issue.

Too wet - Low spots, clay soil layers or overly compacted areas may collect water, which will kill grass. Vehicles can create ruts that collect water. Broken sprinkler heads may also result in saturated soil. See Clemson University's guide "Aerating Lawns" to help fix drainage problems and improve lawn growing conditions.

sparse grass in a shady spot
Shaded area with sparse turfgrass

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Zoysia Grass

You’ve got Zoysia! – Zoysia grass is the one warm-season (Southern) grass type that will grow on Long Island. It is vigorous, dense, stiff, chokes out all weeds and stays green for about half the year (it’s brown the other six months!). More about growing zoysia grass can be found here.

brown lawn grass next to a curb
Zoysia is hardy but goes dormant during cooler months.

Need to Add Grass Seed (Overseeding)

Two images, bare soil on the left, clumped grasses on the right
Bare soil and clumps of grasses show poor growing conditions and a lack of seeding.

Need to overseed and not sure how to do it? Let Cornell's turfgrass experts teach you:

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