Disease Problems

Lawn diseases are usually either foliar or root and are most often caused by fungal infections at times when the lawn is under stress.

Lawn stress can be either from:

  • Improper mowing techniques

  • Droughts

  • Too much water

  • Too little water

  • Watering at the wrong time of the day

  • High temperatures

  • Physical Injury

  • Excess pesticide

  • Excess fertilizer

  • Too little fertilizer

Turf diseases are most likely to form when several of the above stresses are present in a lawn. Disease causing organizisms are almost always present either in the air, or soil, but only when the turfgrass is understress, are these diseases to take hold.

There is only one common grass disease that is not caused by a fungi and that is St. Augustine Decline (SAD) which is actually a virus.

Many lawn diseases have similar symptoms to each other making it extremely difficult for the untrained eye to determine the differences.

Garden Lawns

Fungi Diseases

Fungi diseases are by far the most common lawn diseases seen in North America.

Prevention is Best

Fungicides are rarely suggested for use on home lawns. Instead, it is recommended that sound lawn care practices be followed to prevent serious problems.

In severe disease outbreaks, it may be necessary to allow for a complete renovation of the lawn


Fungicides are used to control many fungi diseases, but extreme care must be taken when using these materials, and only used when proper identification of the disease has been made.

Because so many disease appear similar to other symptoms, it is strongly recommended that a homeowner get professional advice before proceeding with any form of treatment.

Before you purchase any fungicides, read the label to make certain the package you have selected is labeled for your intended use, and then follow all lable directions and precautions. Studies show that a fungicide applied to cure one disease often opens the gates for other diseases to gain entry.

Most lawn diseases will run a certain course and then disappear.

Read more about fungicides and lawn disease...

More about Lawn Diseases

Weed Problems

Identifying Lawn Diseases

Turfgrass diseases are diagnosed by identifying symptoms and signs that result from an infection.

Symptoms represent the plant?s response to infection and colonization by a fungal pathogen.

Symptoms can include leaf spots, chlorosis (yellowing), necrosis (browning), blighting (leaf collapse and decay), stunting, and wilting. Signs are the visible parts of the pathogen-- white cottony mold and powdery spores are most common signs of disease.

Lawn diseases can be managed using:

  • Disease-resistant turf varieties

  • Cultural options

  • Fungicides.

In the rare cases where fungicides are actually necessary, they should be applied by lawn care professionals, who have the technical expertise and experience to apply the product correctly.

Good Cultural Practices

Cultural practices that promote healthy lawns and help them to resist major disease outbreaks include:

Common Lawn Diseases