Question
In the last 2 weeks when I walk in the lawn my shoes get a rust colored powder which is in the lawn grasses. You don't see it but when I mow it, you see it been dispersed in the air by the lawn mower and my shoes and socks are orangy color. What is causing this?

Also, do you recommend any products to control big black ants - I live in a 2 acre very wooded lot which has lots of ants and they get inside the house. Someone mentioned to try diatomaceous earth but the ants are still getting inside the house. I see them climbing the brick walls.

Answer
Good afternoon Bill:
Rust appears as an orange or yellowish-orange powder on grass leaf blades, especially in late summer to early fall when the weather is dry.  Close examination will reveal the spores on the leaf blades, which easily rub off on your hand.
Low fertility (in particular nitrogen) and lack of water availability slow down turf growth, allowing rust to develop.  Cool nights with heavy dew and light, frequent rainfall add to the ideal conditions for rust to develop. Warm, cloudy, humid weather followed by hot, sunny weather also favors rust development. Rust spreads by air, water, shoes, and lawn equipment. Rust may weaken turfgrasses and make them more susceptible to other problems.
Maintain your lawn through sound watering, mowing, and fertilizing. Water early in the day so the grass dries quickly. Manage problem thatch. Increase vigor with an early fall slow release nitrogen application, but don't overdo it. Also assure good airflow over the site and light penetration by pruning trees and shrubs in the area near the lawn.
When rust occurs in late summer, improved growth conditions of early fall often get lawns growing more vigorously and the rust fades away. Apply a winter fertilizer (24-3-12) late in the fall (usually around Thanksgiving Day). If conditions are dry, irrigation is also needed to increase the growth rate of the lawn.
I would not suggest fungicides as they rarely work on home lawns for rust control. Focus instead on cultural practices described above.

Now let's talk about the "big black ants". It appears that you are being over run with Carpenter Ants. You will find all the information you need by copying and pasting the attached web site to your browser and hitting "Go".

http://ohioline.osu.edu/hyg-fact/2000/2063.html

Have a good lawn!
Floyd McMahon