Lawn Disease Identification Part 3: Rust

Rust is a particular fungus which attacks the blades of your grass. It can significantly weaken your lawn, making it susceptible to other diseases.

Let’s look at a the chief causes and how you can beat rust through prevention and maintenance, including aeration. If you need help, don’t be afraid to give us a call!

Rust (Puccinia Spp.)

Rust appears usually when growth of your lawn is slowing down. This may be due to the time of year (late summer/fall), or because of low nitrogen in the soil. The fungus typically forms when there are cool nights with frequent rainfall, or humid conditions followed by bright sun. Anytime grass isn’t allowed to dry out after six or eight hours, rust can begin to form. A thick layer of thatch or infrequent mowing can also contribute to rust formation.

If you suspect you may have rust, pull a few of the suspect blades out of your lawn and check them for yellowish-to-reddish dust or spores. The blades of grass may have started to yellow as well. Another warning sign is that patches of grass will look thin and weak.

The rust inhibits the grass from performing photosynthesis, or feeding itself. This means the grass will be weak and more susceptible to other diseases or pests.

Rust by Yue Jin


Prevention And Mitigation

Once you’ve identified that you have rust, there are some steps you can take to fight the fungus and prevent it in the future.

  • Make sure your lawn is getting the right amount of nitrogen. Nitrogen-poor soil is very conducive to rust growth, so having a proper lawn care and fertilizer plan is important.
  • Avoid watering your lawn at night, as the moisture won’t evaporate as quickly as it does during the day, which creates a good environment for rust.
  • Be careful with your mowing. Mowing more than ⅓ of the blade off at one time, mowing too infrequently or mowing your grass shorter than 3-3-½” can add unnecessary stress to your lawn.
  • Prune trees and shrubs to increase light and air penetration of your lawn.
  • Reduce the amount of thatch you maintain on your lawn. Anything more than ½” is too much and can be reduced by the process of lawn aeration. Lawn aeration removes soil cores from your lawn and deposits them above the thatch layer. This helps breakdown the thatch. At Valley Green Companies, we utilize special aerator equipment which creates 40 holes per square foot.

Remember, if you need help we’re right down the road. Give us a call today!