Lawn Diagnosis: Grub Attack
There are random, irregularly shaped dead patches in your lawn, and you aren’t quite sure why. You may also notice an influx of digging critters such as skunks and raccoons tearing up patches of the grass. If you peel back the top layer of turf and soil, you’ll probably see some fat, milky-white worms that are about an inch long and curl into a C shape when disturbed. These are grubs, and they terrorize your lawn by chewing away at the root structure of the grass.
Organic or Chemical? Choosing Your Weapons
You don’t have to enter your war on grubs without assistance. There are several different tools and techniques you can use, both with and without the use of synthetic and inorganic chemicals. There are pros and cons to each approach; organic techniques can be more labor intensive, and synthetic pesticides can cause damage to plant and animal life you don’t consider a nuisance.
Chemical pesticides such as halofenozide and carbaryl are good for killing off grubs, and they are most effective when applied to the lawn during the grubs’ feeding season in July and August. Really saturate your lawn after applying these pesticides to ensure even distribution and penetration down to the grubs’ level.
If you prefer to go the organic route, you can use tiny live creatures known as nematodes to fight your war by proxy. Nematode strains such as Steinernema spp. are applied live to your lawn. They seek out and invade the grubs’ bodies, injecting them with deadly bacteria and causing a mass grub die-off. When the grubs die, the nematodes don’t have anything to live on and also die, giving your lawn decaying organic matter to feed on. For maximum effectiveness, make sure your nematodes are still alive, be gentle with the container and check expiration dates before applying them.
Prevention Before Intervention
If that all seems like a lot of work, take a strategy of prevention, allowing your lawn to dry out during the summer. Moist soil is attractive for grub beetles searching for a spot to lay their eggs, so a dry lawn results in a dramatically lower quantity of grubs the following year. Some grasses, such as Bermuda grass and bluegrass, handle summer dormancy well and are highly likely to bounce back when temperatures cool and the beetle reproductive season halts.