I was recently asked a question about a rusty coloured lawn that leaves a orange powder
on your shoes when you walk through it. This is something that I have not come across before so I set out to find out more about it. It turns out that lawn rust is fairly common and our current weather conditions are perfect to set it off.
First off, it is mostly cosmetic and will not harm your lawn. It is a sign of a slow growing stressed lawn that is in trouble. A few factors that can cause the lawn fungus to grow include improper watering, soil compaction, low nitrogen levels and heat stress. It often appears at the end of the summer, beginning of fall when the days are warm, the nights are cool and there is a fair amount of dew.
Three easy ways to avoid lawn rust are:
1. Reduce soil compaction by aerating your lawn.
2. Bag your lawn trimmings to keep thatch to a minimum.
3. Water infrequently, and deeply and not at night.
If you already have lawn rust:
1. Mow the lawn frequently to keep it to a moderate height
2. When you cut your lawn, rake the thatch and remove it or bag it so the fungi does not spread across your lawn.
3. Rinse off your lawn equipment to prevent spread of the disease.
4. Water early in the day
5. Test your soil before fertilizing in the fall and add nitrogen if necessary. (September is the optimum time to fertilize)
6. In most cases, applying a chemical control is not recommended or necessary.
If certain parts of your lawn are consistently being affected by lawn rust, you might consider replacing the sod with a rust fungus resistent grass species such as Kentucky bluegrass and rye grass. Another alternative is to consider naturaliing this part of your lawn with groundcovers or flower beds that are better suited to the moist conditions.
If the infection is severe and the rust makes an annual appearance, it would be appropriate to apply an organic lawn fungicide rated specifically for your lawn disease. This measure is a last resort and will not help your grass rgrow. However, it will keep the fungus spores in check until your improved lawn care practices can take effect.