Last week, Signal Mountain resident Kevin Liendecker noticed a brown stretch of grass about 25 feet long in the rear of his backyard.
When he looked at the yard a couple of days later, about 15 more feet of grass had turned brown.
At first he thought it was the recent wet weather affecting his grass and didn't think much about it. But when he saw half his yard was brown the following day, he went outside to investigate and noticed white specks all over the ground.
After a bit of research and a call to his lawn care company, he discovered the culprit behind the devastation of his lawn was the fall armyworm. The worms devoured all the grass in his backyard and a portion of the front, about an acre in total.
"They eat it all the way down to the base of the grass, so there's no green left," he said.
His lawn care company was so covered up with requests for armyworm treatments that it would have taken three or four days before they could get to his yard.
"By the time they would get here, my whole lawn would be gone, so they recommended that I treat it myself," he said.
Liendecker went to Ace Hardware and purchased neem, a naturally occurring pesticide, which he applied on the few remaining green patches. That killed the worms which have yet to return, he said.
"I'm definitely going to be diligently watching to make sure there's not any more that come into my yard," Liendecker said.
Armyworms are hitting the Chattanooga area hard this year, overwhelming lawn care companies and clearing pesticides from the shelves of local stores.
In the 45 years since Ray Painter opened Green Thumb Nursery in Hixson, he can recall only one or two other instances when he received as many calls about armyworms, which are moth larvae about 1 to 1 1/2 inches long that can destroy an entire lawn in a matter of days.
Painter said Green Thumb is out of the granular insecticide typically used to kill armyworms. Trey Forrester, team leader at Elder's Ace Hardware on the Southside, said granular insecticide is nearly out of stock at that store.
"It's very abnormal that we've run out," he said.
Weed Man co-owner Kyle Rossi said his Middle Valley lawn care service has been inundated with calls for armyworm treatments since last week.
"It's all hands on deck right now," said Rossi, who's been asking customers to put off other lawn treatments so the company can prioritize treating armyworm infestations within 24 hours of the customer's request. "If we can't get out within 24 hours, the damage can be catastrophic."
Armyworms can destroy an area of grass the size of a football field within 48 hours, he said.
"They call them armyworms because they almost line up from where they start and they go out equal distances apart, kind of like an army marching across a field," Liendecker said.
Large swaths of discolored grass, as Liendecker observed, are usually the first indication armyworms have taken up residence on a lawn, Painter said.
Liendecker's parents also experienced an armyworm infestation in their yard in Hixson. But it wasn't brown grass that tipped them off to their guests. They noticed that their chickens were staying in the yard rather than coming in to eat. When they went out to the yard they discovered the birds were gorging on little black worms.
Rossi said only about half of his customers with armyworm infestations can see the worms on their lawns. If no worms are visible but irregular damage to the grass is present, he recommends adding dishwashing liquid to a five-gallon bucket of water and pouring it onto the grass. If worms are present, that should bring them to the surface, he said.
Weed Man uses a two-part process to treat an armyworm infestation, first a liquid insecticide is applied to kill the worms on contact followed by another application of granular insecticide to provide residual control. The granular insecticide is absorbed into the grass, and if another generation hatches it will kill the larvae that eat the grass within the next 21-30 days, Rossi said.
You can also treat your own lawn using insecticides such as neem pellets, triazicide or Sevin.
The likelihood of the grass returning after the worms are gone varies based on the type of grass.
Rossi said Bermuda grass often comes back in a few weeks, but if armyworms are feasting on your fescue it will most likely need to be reseeded in the fall.
But understand this
Unfortunately, there's no way to prevent armyworms from coming into a yard. Although they can crawl from one yard to another, their main mode of travel is the flight of moths, according to Dr. Scott D. Stewart, professor of entomology and integrated pest management specialist in the University of Tennessee Institute of Agriculture's Department of Entomology and Plant Pathology.
The moths, which can fly for hundreds of miles, fly in from Mexico and Texas and lay eggs here. They can lay a mass of about 200 eggs, he said.
"You sadly just have to wait," Stewart said. "They migrate every year and when they get here, they get here."
When the eggs hatch, the larvae start to look for grass to eat.
The worms prefer some types of grass over others — especially tender or young grasses, such as Bermuda — but there's not a type they won't eat, Stewart said.
Contact Emily Crisman at firstname.lastname@example.org.