Your lawn has developed unattractive areas of reddish or yellow discoloration. You've even noticed orange dust when you mow the lawn, and it gets on your shoes when you walk on the grass. That substance looks like rust, and fittingly enough, the fungi that cause it have collectively become known as rust disease. Fortunately, some effective methods can help you resolve the problem and prevent it from happening again.
Commercial products containing sulfur or copper stop rust fungus growth. Spray the fungicide on the affected areas once each week or as directed on the label. Do so early in the day when the temperatures are relatively cool, the humidity is relatively high compared to the rest of the day, and winds tend to be calm. That prevents the fungicide from evaporating or blowing away.
Avoid using fungicides containing harsh chemicals that can be harmful to the grass and other plants, as well as to beneficial insects and birds.
Apply Neem Oil
This substance is primarily known as an insecticide, but it's also effective at eliminating rust disease. You can buy commercial neem oil products in liquid formulations and in packets of powder to mix with water.
If you've already applied a commercial fungicide, wait at least two weeks before applying neem oil. The combination of the two can burn the grass.
Stop Rust Spread
Rake up dead leaves and thatch at least once each week, and bag grass clippings when you mow. Hose off the lawn mower blades and rake when you're done.
Prevent Future Problems
Add Seed and Fertilizer
With a spreader, add grass seed of species bred to resist rust and other disease. Include a low-nitrogen fertilizer with the seed to provide nutrients for your lawn. Do this now to strengthen your existing grass. In the future, add the seed and fertilizer once in spring and once in fall.
Cut the Grass Properly
Have your lawnmower blades sharpened at least once a year, and again if you notice any chopping effects on the grass. Have the blade set so the grass is never shorter than 3 inches tall. Otherwise, it doesn't have enough foliage to effectively generate food through photosynthesis. It then can become weak and susceptible to disease.
Use Effective Watering Techniques
Fungi tend to grow best with shallow, frequent watering. Instead, water only a few times each week at most, and drench the grass. With this method, the water reaches the ends of the roots, helping them become stronger and grow deeper. That means healthier grass plants.
You can do this work on your own or hire a lawn maintenance service to complete the projects. You may want to have an irrigation system installed so you don't need to water the grass manually. Soon your lawn will look great again and you won't have to worry about rust fungi or other diseases that damage grass. For more information, check out sites such as Headman Lawn Care and Christmas Lighting.