Armyworm damage almost looks like grubworm damage but when you pull up on the grass it is firmly rooted, whereas grubs eat off the grass just under the dirt and pulling on the grass causes it to come up like sod with a layer of dirt attached to the roots.
Armyworms tend to do a lot of damage in a short amount of time. They eat the grass blade down to the crown. Armyworms do not necessarily kill the grass — the crown and root system usually survive if treated promptly.
If you suspect armyworm damage, look for the worms themselves. They're typically 1 to 2 inches long and can be green, brown, or black with stripes. They feed most actively in the early morning and evening.
If you want to spray for armyworms, Tempo or Talstar works very well. Spray Tempo at a rate of 6 to 12 oz per acre. Talstar P at .18 to .25 oz per 1,000 sq ft. We recommend you read the label yourself if you intend to spray.
If you notice large brown patches appearing rapidly in your lawn — especially in late summer or early fall — give us a call. Quick treatment makes the difference between a lawn that recovers and one that needs more serious work.