| | | TROUBLE SHOOTING | Trouble Shooting Established Lawns (older than one month)
Brown lawn areas are most commonly caused by one of three types of problems: Improper watering, burn, or disease. Check for watering and burn problems first before treating for disease.
To check for lack of water use a screwdriver or knife to probe the brown areas of your lawn as well as the healthy green areas. If the brown area is more difficult to penetrate then a lack of water is likely. This is usually the result of poor sprinkler spacing or sprinkler malfunction. Saturate the area with a hose as soon as possible and continue to provide supplemental water until the sprinklers are repaired.
Excess water can cause turf to die by suffocating the plants roots or rotting its crown. This generally occurs in low spots or shady areas. Check for muddy soil, algae crusts, or slimy rotting grass. To correct problems in the shade reduce irrigation time to that area or replace the sprinklers with lower volume heads. Low spots must either be raised or drained.
Brown spots caused by a burn will result from pet urine (both male and female), over fertilization, gasoline spills, etc. Burn spots are distinguished from other types of damage by their "total kill" straw-yellow color. Dog urine burn spots that are over a week old will be surrounded by a dark green taller growing perimeter. If a burned area is thoroughly flushed with water in the early stage of damage some recovery may occur. Otherwise reseeding or sodding will be necessary.
Diseases are almost always related to heat and moisture. The most susceptible months of the year are July, August, and September. High humidity creates an ideal disease environment. However, poor irrigation practices can also promote disease development. The longer moisture stays in the turf foliage the greater the disease risk. Therefore, do not water at night, (between 4 pm and 4 am) since the lawn will stay wet until morning. It is best to irrigate between 6 am and 8 am. Weather permitting, do not water established sod everyday. Also, reduce fertilization in the summer.
When brown spots first appear observe them from one day to the next, if more develop you probably have an active fungus. During periods of high humidity small six inch diameter spots may multiply, overlapping to become a large area. The grass may be collapsed to a point of lying matted flat and rotting. This is symptomatic of the fungus pythium. Reduce the frequency of watering so that the diseased areas will dry out. Also, make sure that when water is reapplied it is between 6 am and 8 am. Lightly rake up collapsed matted areas to air out in order to prevent recovering shoots from suffocating. Use a broad spectrum fungicide such as Daconil or Fore as recommended by your nurseryman. Always apply the fungicides according to label directions. Another option is to call a lawn care service.
Spraying will usually stop the disease from spreading. Be patient with areas that have been damaged, often a high percentage of recovery will occur. If reseeding or sodding is required wait until the cooler times of the year.
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