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University of Rhode Island GreenShare Factsheets

What's Wrong With My Lawn?


Lawn problems can occur in small areas or larger patches ,or entire lawns can die. Sometimes the problems are due to poor growing conditions, improper lawn care practices or extreme weather conditions. The following list is a guide to help you decide what conditions may be causing problems in your lawn. Further information and fact sheets are available for more detailed help.

After Winter but Before Spring Green-Up

  • Winter Desiccation--Large areas of straw-colored grass, especially where exposed to wind with little snowcover.
  • Spring Frost Damage--new leaves killed back
  • Water and Ice Damage--Straw-colored or rotted grass, especially where water collects in frozen soil
  • Snow molds--look for white pink and gray mold in circular patches on moist grass
  • Salt Damage--dead or yellowed grass along sidewalks, driveways or roads where salt has been applied
    -water heavily to try to wash away salt
    -reseed where lawn is thin.
    -Avoid salt when possible. Try sand, cat box filler, etc. as a substitute for deicing salt.

    Preventive Measures:

  • In spring:
    --Rake away dead grass.
    --Reseed thinned or bare areas when soil is well-drained and warm with night temperatures above 35 degrees F.

  • In fall:
    Avoid snow molds by mowing as long as grass grows in the fall.
    Avoid fall nitrogen applications that delay dormancy.
    Prevent deep piling of snow along walks and driveways.


After Spring Green-Up

Soil Problems:

  • Compaction
    -Aerate the soil
    -Add organic matter during lawn reconstruction
    -Re-route foot traffic and play areas to avoid frequent packing-down of soil
  • Over-liming soil or acid soil
    -Have soil pH tested
    -Adjust pH as recommended
  • Low nutrient levels: Yellowed, slow-growing lawn
    -A balanced soil fertility of nitrogen/phosphorus/potassium (NPK) promotes a healthy lawn
    -Have soil pH tested.
  • Improper fertilizer application:
    -Over- and under-fertilizing can result when spreader is not calibrated properly. Take special care when turning. Brown streaks lined with extra green growth can occur in areas of application overlap. Yellow nutrient-deficient streaks may occur in missed areas.
  • Dog Urine:
    Spots of brown grass, perhaps with green area around them
  • Foreign chemicals and gas damage:
    Many household chemicals, salt, oil, gasoline, concentrated fertilizers, herbicides and gas leaks can cause sudden scorched areas in lawns at spill sites.

Water Problems:

  • Too Much Thatch:
    -Remove thatch layer if greater than 1/2 inch in thickness--thatch harbors pathogens and insect pests and prevents grass plants from absorbing nutrients and water properly.
    -Prevent thatch by avoiding excess fertilizer and fungicide applications.
    -See our GreenShare Factsheet on Thatch for more information.
  • Watering:
    -Water deeply (to a depth of 6 inches) when necessary
    -Water early in the day so foliage will dry quickly. Night watering (after dew appears) is not recommended during very hot, humid weather because of diseases.
  • Too little Water:
    Wilt (blue-green color and footprints easily visible), browning and death can occur. Some turfgrasses (e.g. Kentucky bluegrass) will go into dormancy in drought but will green-up again when moisture returns.
  • Too Much Water:
    Deprives roots of oxygen, stunts growth and promotes root and crown rots.
  • See our GreenShare Factsheet on Efficient Watering of Turf for more information.

Light Problems:

  • Shade: Most lawns will be thin in shaded areas
    -Selective pruning of branches may let in enough extra light to promote grass growth.
    -Plant shade-tolerant turfgrass cultivars or other groundcovers in heavy shade.
    -See our GreenShare Factsheet on Growing Turf Under Shaded Conditions for more information.

Mowing Problems:

  • Mowing Height:
    -Mow at 1 1/2 to 2 1/2 inches, with maximum in hot, dry weather
    -Avoid 'scalping,' especially in irregular, bumpy areas
  • Mowing Frequency
    -No more than 1/3 of total length at any cutting so grass is not stressed
  • Clippings:
    -Can generally be left except during a disease outbreak.
  • Machinery:
    -If grass blades look brown and shredded, sharpen and adjust blades

Disease Problems:

  • Circular patches and/or rings of dead and/or unusually green grass:
    -Note size and patterns.
    -In the morning, when grass is still dewy, look for the web-like threads of the fungus and/or mushrooms on the lawn.
    -Dig up a section of dying grass and examine the roots for dark color and evidence of root and crown rot.
  • When grass is thin or dead in an irregular area:
    -Examine individual grass blades for
    -- leaf spots (probably tan with dark borders)
    --evidence of fungus--orange, black or white powdery spores
    --gelatinous red threads
    --slimy or powdery white, orange or brown mold

  • General Practices that Reduce Disease:
    -Keep foliage as dry as possible
    -Mow when grass is dry
    -Landscape to allow good air circulation
    -Collect clippings when fungus is active in lawn
    -Avoid nitrogen fertilizers early in spring, in hot weather and just before grass becomes dormant
    -Choose disease-resistant cultivars when possible

Insect Problems:

  • White Grubs: gradually increasing patches of thin turf, often looks like drought stress, sometimes accompanied by skunk or raccoon damage (lawn torn out in chunks); usually observed in May to early June or in September and October.
  • Chinch Bugs: Generally observed in sunny areas or on sandy soils, often confused with drought stress; usually observed during hot periods in July and August.
  • Bluegrass Billbugs: Sporadic in New England. Usually begins as yellow areas along the edges of driveways and sidewalks; usually observed in July or early August; adults may be seen on pavement in late May or early June.
  • Sod Webworms: Adults are small moths which fly just above the ground at dusk; damaged areas begin as small discrete patches which can spread into larger areas; feeding (by caterpillars) occurs at night.

 

Adapted from Gail Schumann and Richard Cooper, University of Massachusetts Cooperative Extension Service, 2001

Pesticides are poisonous! Read and follow all safety precautions on labels. Handle carefully and store in original containers out of reach of children, pets or livestock. Dispose of empty containers immediately, in a safe manner and place. Pesticides should never be stored with foods or in areas where people eat.

When trade names are used for identification, no product endorsement is implied, nor is discrimination intended against similar materials. Be sure that the pesticide you intend to use is registered for the state of use.

The user of this information assumes all risk for personal injury or property damage.

For more information, call the URI CE Gardening and Food Safety Hotline at 1-800-448-1011 or (401)874-2929 from outside Rhode Island; Monday-Thursday between 9 am and 2 pm.

 

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