Lawn Fungal Diseases - Identifying and Controlling

When your lawn is attacked by disease getting it under control can be difficult unless you know how to identify the fungal disease and understand the causes.  Fortunately good lawn care and maintenance can resolve current and prevent further disease episodes.  We have listed the main fungal diseases below with their identifying markers.  We have also given tips on how to tackle fungal disease and hopefully keep it at bay.

There are 3 factors that favour fungal disease development:

  • Weather conditions that favour disease
  • Disease pathogens in the soil
  • Susceptible lawn grasses

Unfortunately we cannot control the weather but we can learn how to identify different diseases, their causes and how to resolve them.  Active fungal disease can occur when the grass is under stress.  This could be poor climate conditions or poor soil conditions which encourage fungal activity.  

We have listed below the main fungal diseases that can occur in lawns.  With each disease is a photo to help identification and an explanation of identifying markers on each page. Just click on each disease name and that diseases' information page will pop up.

    Controlling Fungal Disease In Your Lawn

    Once you have identified your fungal lawn disease, good lawn maintenance can control and prevent future episodes.  Quick adjustments in your lawn care can return your lawn to it's best in no time.  The following lawn care practices will help keep your grass in top condition:

    • Keep soil pH at optimum grass level, between pH5.5-6.5.  This keeps soil pH at a level where nutrients are easily available to your grass roots.  Regular soil testing is the best way to be sure you have got it right.
    • Fertilizer properly.  Check the Nitrogen level of your soil before you fertilizer as it could be you are over fertilizing or under fertilizing.  Either way this puts stress on the grass and so leaves it vulnerable to disease. (See our Soil Test Kits to keep you right).
    • Water carefully during dry periods to keep lawn health at an optimum.  Irrigate late evening when the sun is low and temperatures have dropped.  This reduces the chance of leaf burn and quick evaporation.  Don't water frequently, instead water deeply.  Good volumes of water twice a week to encourage deep drought tolerant root system.  Irrigation equal to 1 inch of precipitation soaks the soil to a 4-6 inch depth.  This encourages strong roots and healthy grass.  Always adjust to accommodate that weeks rainfall or the lack of it.
    • Follow good mowing practices.  Keep grass at the ideal height for that mixture/grass varieties.  Keep mower blades sharp and mow according to grass growth not the time of year.  Remove only 1 third of the blade height in a single mowing.  If you suspect fungal disease  always collect and dispose of lawn clippings in a bin, do not compost them.  Some diseases can spread through your compost. 
    • Dethatch lawns and aerate soil regularly ( using garden fork or aerator put holes in the lawn).  Thatch up to 1/2 inch thick acts as a good mulch.  Anything above this then restricts water seeping into the soil, and air circulation.  These conditions encourage disease to take hold.  
    • Use fungicides for severe infestations - always follow the product instructions to the letter.

    You can buy our soil test kits by following this link:  SOIL TEST KITS PAGE