Insect Repellent Can Harm Your Lawn
Doing yardwork this time of the year comes with its many challenges.
Working through heat and humidity, and dealing with insects such as mosquitoes and chiggers, are just some of the challenges the Minnetrista grounds crew and gardeners face each day.
Working smarter and drinking plenty of water are ways to survive the heat. The use of a good insect repellent works wonders for keeping insects at bay. But something else became more evident this week. When we solve one problem, oftentimes we bring about another problem, and the use of insect repellent is an example of that.
Let me explain. During a recent week, as we were setting up for a Faeries, Sprites, & Lights on the Oakhurst Formal Lawn, I noticed some unusual brown spots on the turf along the edge of the perennial border.
At first I reasoned that it must be a turf disease. Turf disease is common here when we have hot and humid conditions. But that didn’t make too much sense, because this year I added fungicide to my management program on the Formal Lawn to control Brown Spot and other turf diseases.
Then my mind went toward herbicide damage. But no one had sprayed herbicide on that portion of the lawn. What could it be? I was determined to find the answer.
I was discussing this problem with Dustin, our Horticulture Manager, and he came up with a thought. With all the work going on in preparation for the big event, many people were spraying themselves with insect repellent. Upon further investigation, that is indeed what had happened. A group of people had used that very location to apply repellent.
I did some follow up research on the matter. University studies have shown that insect repellents with, a high percentage of DEET can cause severe damage, or even death to grass. There is a possibility, depending on the amount used, that in about two to three weeks, that grass will completely recover. So we will have to wait and see.
The take home lesson on this one is, do not spray repellent on yourself while standing on your lawn. Do it in the driveway.
I am glad this mystery was solved. I was scratching my head over this one. Or, was I scratching a mosquito bite . . .