Do I Have a Lawn Grub Problem?
Lawn grubs can sometimes be present in your lawn but cause absolutely no problems. If left untreated they can destroy a lawn in no time . But how do you know if you have a real lawn grub problem?
Since grubs eat grass roots, the lawn will be easy to pull up in chunks. If it’s still firmly rooted, then you have another problem, such as brown patch or dog urine damage. Here’s a good test, from the University of California Integrated Pest Management Program: Pull up about 1 square foot of the earth around the base of your sod (where the stems meet the roots). If you notice more than 6 grubs in this space, it’s a good time to consider preventive methods or treatments to reduce overpopulation.
Shetlar, however, recommended that lawn lovers should be even more vigilant, especially in order to prevent large critters from eating them. When talking about the maximum threshold of tolerance for grubs, “I always chuckle about [checking the threshold], in that skunks and raccoons haven’t read about this threshold.”
As such, it may be worthwhile for homeowners to be just a little warier on account of skunks and raccoons. Shetlar added, “If there are four to five grubs per square foot, that’s usually enough for them to be digging around.”
Once grubs are established, what can you do about it? The most common (and, sadly, most effective) ways to kill grubs are chemical insecticides. Effective insecticide control products against grubs include imidacloprid, thiamethoxam and clothianidin. However, they only work if used in the lawn in June and July. If you wait until August when the brown patches appear, it’s too late. The chemicals carbaryl and trichlorfon that are considered curative treatments — they are short-lived products effective immediately.
Always follow label directions carefully when using any chemical pesticide. Any use poses a risk of harm to not just people, but other insects, including lawn-beneficial pollinators. One way to mitigate the damage: Mow your lawn just before applying so there are no weed flower heads to attract the pollinators to your temporarily poisoned yard.