Why is My Lawn Turning Brown?

Brown patches and lawn browning is a common problem that most homeowners face. Disease, poor maintenance issues and improper irrigation contribute to brown lawns. Identifying the causes of lawn browning can help you prevent further lawn injuries and help correct the problem. Although this list is a short guide, it will help identify the most common lawn problems that contribute to browning or lawn death.

Fertilization
Whether you are planting new grass seed, or maintaining an old one, fertilization is necessary for a healthy lawn. Lawn fertilizer contains three macronutrients nitrogen, phosphors and potassium, as well as variety of secondary micronutrients for growth. However, the improper ratio of these nutrients can contribute to lawn browning. The nutrient nitrogen helps root growth and green foliage, but too much nitrogen causes something known as fertilizer burn. This conditions occurs because the salts in fertilizer make it difficult for plants to obtain water, thus causing browning.

Herbicide Damage
Herbicides are unavoidable for getting rid of unwanted plant growth. However, some homeowners do not know the difference between selective for broad-spectrum herbicides. Selective herbicides target specific types of weeds, which if applied properly, can eliminate weeds without damaging your lawn. However, broad-spectrum herbicides kill all forms of susceptible plant life, including lawn grass. Check herbicide labels to see if the chemicals can damage your type of lawn seed.

Proper Irrigation
Lawns require watering for healthy and hardy growth. Lawn irrigation depends on your locations; dry regions may use automatic irrigation systems, whereas seasonal rainfall may suffice for other regions. Browning of lawn grass is a good sign that your lawn isn't getting the amount of water it needs. Be sure to irrigate your lawn during periods of dry weather-conditions. However, avoid over watering because too much water contributes to fungal disease growth.

Lawn Diseases
A variety of diseases contributes to dying or browning of lawns. Lawn diseases vary depending on the growing region and soil conditions. Fungal diseases are common agents for infecting lawns. Avoiding fungal diseases consists of not overwatering, applying preventive fungicide and getting soil samples checked for soil borne diseases. Soil borne diseases are the most difficult to control because fungicidal control cannot always control these diseases. Local universities and private labs can test soil samples for nutrient contents and diseases.

Lawn Grubs
Grubs are small white insect larvae that feed on the roots of grass. The feeding on the roots causes reduced vigor and lawn browning. Lawn grub infestations are most serious during the late summer, when grub populations are greatest. Grubs infest green lawns that have adequate soil moisture. The University of Illinois recommends reduced irrigation if grub infestations occur annually, beneficial nematode control and chemical control. Beneficial nematodes are small parasitic organisms that devour and kill their host without damaging your lawn. The University of Illinois recommends Heterorhabditis bacteriophora, a type of nematode, for controlling lawn grubs.

Sources:

http://urbanext.illinois.edu/lawnfaqs/grubs.html

http://soil.gsfc.nasa.gov/soilfert/npk.htm
http://hort.uwex.edu/articles/herbicide-damage