Q. Just recently I’ve noticed a rust-colored dust all over my wife shoes after being out in the lawn. I mowed the lawn the other day, and the mower was covered with it afterward.
The lawn is overall green, but you can detect a brownish red color throughout. I’ve been told to contact you folks because it could be some fungus or disease. Do you know anything about this condition?
A. Sure sounds like you have rust in the lawn.
Rust is a fungal disease that appears in some lawns in northeastern Indiana in late summer and early fall. The spores of the fungus are actually blown in from the South on storms.
Rust generally won’t kill or even severely damage a lawn, but the rust-colored fruiting bodies of the fungus can make shoes turn orange. In addition, asthma sufferers can sometimes suffer from being exposed to the mold spores. In rare cases, animals can suffer from allergy symptoms when exposed to rust in lawns.
Rust generally is more of a problem in under-fertilized lawns and in lawns that have more perennial ryegrass than bluegrass.
I would fertilize the lawn now and again in late October with a fertilizer with slightly higher rates of nitrogen. The numbers on the bag should read something along the lines of 18-10-10 or something close. The fertilizer will help the lawn outgrow the fungal issue and also help the lawn recover from the summer drought. The rust also will generally disappear on its own as we head into late fall.
If you have part of the lawn that is infected with rust, and another section that is not infected, mow the non-infected area first. Then mow the infected area. You might want to wear a dust mask if you are sensitive to molds, or have someone else who is not sensitive mow the lawn. Collect your clippings on the infected area. Put the clippings in the compost heap or bag them and send off to the landfill. If you compost correctly, then the composting process will kill the spores.
Wash the mower blades and underside with clear water, and then spray a weak Lysol solution or similar disinfectant on the blades and underside. This will help prevent you from spreading the disease to other areas of the lawn. If you have a newly established lawn, or you actually see severe damage, contact a lawn professional.
Finally, try and keep your animals – dogs in particular – away from the infected areas of the lawn. Wash or vacuum the paws and coat of the dog if possible before the dog re-enters the house so that the rust spores are not brought into the home to cause allergy symptoms in sensitive people. The same goes with shoes – wash them before re-entering the home.
In the big scheme of things, rust isn’t a huge issue but it can be an annoyance, especially for sensitive people or pets with allergies.