Dead spots in Lawn - Ask Extension
See the dead spots in the lawn on the attached picture dated 6-13-22. There are many more dead spots in the lawn than what is shown. Most if not al...
Knowledgebase
Dead spots in Lawn #807915
Asked August 24, 2022, 9:30 PM EDT
See the dead spots in the lawn on the attached picture dated 6-13-22. There are many more dead spots in the lawn than what is shown. Most if not all of the the dead spots are in full sun. I think the dead spots were in the lawn much earlier than June 13. I dug up severals spots in June and could not find any grubs. I did get some grub control (Lesco Bandit 2F) applied to the lawn on July 15. This was the first application of grub control ever on the lawn. So do you think the dead spots were caused by grubs? GO GREEN!
Ottawa County Michigan
Expert Response
The life cycle of (mature) grubs feeding on turf (Japanese Beetle and/or European Chafer) is that they pupate in May and hatch as beetles in late June or July, thus no grubs to be found. However your application of Lesco Bandit 2F (containing imidacloprid) was spot on to target newly hatched grubs in August (hopefully you watered it in)! More info here:
How to Choose & Apply Grub Control Products-MSU
Dealing w/ Grubs in the Lawn-Illinois
Control Lawn Grubs w/ IPM-PSU
You have applied a 'Preventive treatment' against the next generation of grubs.
Your photo isn't detailed enough to positively confirm that the brown spots are grub damage. They could also be caused by drought, poor soil or turf diseases. I'm hesitant to think it's drought as MI wasn't the dry in late May-early June. Regarding soil testing...have you done a soil test on your lawn in the past 3 years? It will tell you your soil type, pH, fertility and more - helping you to properly fertilize your lawn and have a stronger, denser turf to look better, resist disease and fight insect infestation. It only costs $25 and they will provide you with a fertilizer recommendation in addition to the analysis of your soil sample. Knowing the condition of your soil is the starting point to establishing & maintaining a good lawn. More info here: Don't Guess-Soil Test-MSU and MSU Home Soil Test-self mailer
I'm also attaching links to several university websites on turf diseases so you can check out possible diseases like dollar spot, necrotic ring spot, spring leaf blight or take-all patch:
MSU Turf disease ID
Purdue turf disease ID
Turf Diseases & Pests-PSU
Managing Patch Diseases in Lawns-Illinois
How to Choose & Apply Grub Control Products-MSU
Dealing w/ Grubs in the Lawn-Illinois
Control Lawn Grubs w/ IPM-PSU
You have applied a 'Preventive treatment' against the next generation of grubs.
Your photo isn't detailed enough to positively confirm that the brown spots are grub damage. They could also be caused by drought, poor soil or turf diseases. I'm hesitant to think it's drought as MI wasn't the dry in late May-early June. Regarding soil testing...have you done a soil test on your lawn in the past 3 years? It will tell you your soil type, pH, fertility and more - helping you to properly fertilize your lawn and have a stronger, denser turf to look better, resist disease and fight insect infestation. It only costs $25 and they will provide you with a fertilizer recommendation in addition to the analysis of your soil sample. Knowing the condition of your soil is the starting point to establishing & maintaining a good lawn. More info here: Don't Guess-Soil Test-MSU and MSU Home Soil Test-self mailer
I'm also attaching links to several university websites on turf diseases so you can check out possible diseases like dollar spot, necrotic ring spot, spring leaf blight or take-all patch:
MSU Turf disease ID
Purdue turf disease ID
Turf Diseases & Pests-PSU
Managing Patch Diseases in Lawns-Illinois
