Bright Yellow Lawn-What do I do?

Asked August 22, 2018, 11:17 AM EDT

My back yard has large areas of yellow stuff on my lawn. I am not talking about dead areas or dormant. I mean yellow stuff that is coming off on my dog's white fur. It almost looks like yellow paint, but it seems to be coming from within the grass blade. In the morning dew, it will appear in beading on the grass blade and come off on my fingers if I run them over a yellowed blade. Looking at the yard, these areas appear as a yellow-green color. I have never seen or heard of this before. What is this? What do I do? I don't know if it is harming the lawn or just annoying. I do have a vegetable garden, flower garden and a back yard pond. My back yard gets close to or equal to full sun. We are just ending a second or third year of a huge amount of Japanese Beetles. We are used the bag system over the summer to eliminate the beetles.

Dakota County Minnesota lawns and turf horticulture

1 Response

Turf rust is seen in late summer as the growth slows. It is more present during rainy summers that create the damp environment that nurtures the development of it. Rust can more easily develop on turf that is lacking in nutrients. There are no chemical treatments for rust but rather you should work on maintaining a healthy lawn. One place to start is with a soil test. See http://soiltest.cfans.umn.edu/ for details. The report you get back will tell you what is missing and give specifics and what to add.

This September would be a good time to fertilize your lawn and bring it back to vigorous growth. Be sure to keep the turf amply watered. Continue with Fertilization next spring. Here is a link to a lawn care calendar: https://extension.umn.edu/planting-and-growing-guides/lawn-care-calendar

This is nice overview of rust in lawns: http://extension.illinois.edu/turf/rustlawn.cfm