Over the past several weeks, Armyworms have been devastating lawns across the United States. As of late last week, there are reports of Armyworms in the Twin Cities.
What are Armyworms?
What damage do Armyworms do?
How are Armyworms controlled?
Armyworms are a moth. These moths overwinter in Southern states and move North throughout the summer. They feed on grass crops and lawns. In most recent years, the summer has not been warm enough or long enough for Armyworms to make it to Minnesota. Armyworms die after frost and cannot overwinter in Minnesota. Their arrival this year is a once in a decade or multi-decade scenario.
Armyworms feed on grass blades, which causes them to turn brown. Large populations can turn a green lawn brown overnight. Lawns can recover if the feeding is light and proper post care occurs. More significant feeding can kill grass.
Because Armyworms can damage an entire lawn overnight, control methods are focused on preventing the feeding. Application after damage has occurred will only prevent additional damage. If a lawn is damaged by Armyworms, the lawn should be regularly watered and receive a fertilizer application to encourage recovery. In severe cases, lawns may need to be seeded. Should you have your lawn treated? It’s hard to say with certainty. Our network in other states where damage has been severe report that spring grub treatments provide some protection. With frost only a few weeks away, we are hoping that Armyworm populations will not build in time to cause damage in the Twin Cities.
If you notice any of these symptoms on your lawn, please take some photos and contact our office.
Additionally, here is a link to a USA Today article about the outbreak. https://www.usatoday.com/story/news/nation/2021/09/01/fall-armyworm-outbreak-damages-lawns-across-us/5683595001/