Dealing With Grubs

Grubs are the bane of lawns across the land. They can turn a beautifully green expanse of perfectly manicured splendor into a brown patchy wasteland.  It’s a problem that many homeowners find themselves in the middle of and it can lead to even more problems if left to persist.


June Beetle

June Beetle aka Junebug

What are Grubs?

Grubs, also called grubworms, are the larval stage of the Junebug.  There are about 100 species of this beetle in Texas alone. Depending on the species, these bugs have an average lifecycle of year or two. In late spring and early summer the adult beetles emerge, earning the nickname “Junebugs,” and search out a mate. The females dig down about two to five inches into the soil and lay their eggs. Within about two weeks the eggs hatch and produce small white c-shaped grubs. These grubs feed on the grass roots of cultivated turf. The bug remains in the larval stage until the next spring when it briefly enters the pupae stage, completes its metamorphosis, and then emerges as an adult June Beetle when the conditions are optimal.

The larvae begin their life in mid to late summer. However, because some species of the bugs have longer lifecycles the damage to your lawn can be evidenced in spring, summer, and fall. The larvae feed on the roots of your lawn and cause your lawn to die. Beyond that, grubs attract their own set of predators that can do further damage to your lawn. Moles, raccoons, and skunks all find grubs to be utterly delicious and will further ravage a yard already damaged by the grubs activity.

Preventative Tactics

I think we can all agree that preventing a grub problem from taking hold is much better than have to treat a problem that has emerged. There are several things you can do in order to create conditions that are unfavorable to the Junebug from laying its eggs in your soil in the first place. You can start by raising that blade on your lawnmower. Keep your grass at least two inches high in order to make your lawn too much work for the beetle. On that note, over-seed and fertilize your lawn. Having a nice thick hearty lawn is not only beautiful but it’s so much more work for the beetle to deal with. When given the option it will choose a less cumbersome place to lay it’s eggs. You may also want to change your watering schedule. If you have a sprinkler system you turn on for a few minutes every evening consider watering once a week for a bit longer. Grubs need moisture and if you let your lawn dry out it’s a lot harder for the grubs to take hold.

How Do You Know If You Have a Problem?

grub damaged grass

Grub damaged grass

Does your lawn look like this? It could be grubs. If your lawn is exhibiting dead patches it’s time to investigate further. Pull back some of the turf and look for grubs. If you do have a problem then it’s often not difficult to confirm if their the root of your root destruction. To determine the extent of the problem check several different areas of your yard. Pull back, or cut, sections of lawn at least 4 inches deep and 4 inches wide. If you find more than four or five grubs in one of these blocks you need to consider treating your lawn.

Treating for Grubs

Your first step is to contact your local agriculture extension and have them help determine when the best time to treat for your area is. If your not really in tune with your local Junebug population you’ll appreciate the assistance you can get from your local Master Gardeners and similar groups.

You can treat the grubs chemically and non-chemically. If you decide to treat chemically make sure that you follow the instructions for use  precisely and make very sure you have consulted your local experts and are treating at the right time. Too soon and the chemical may not be effective enough when the eggs begin hatching. Too late and you could be dealing with grubs that have matured to the point where they are quite difficult to kill.

You can treat biologically with Milky spore powder. Milky spore is a natural bacteria that can be a very effective control against grubs. That said, it’s going to take a few years for it to become established in your soil and if you choose this route you must not utilize other treatment methods because in order for the Milky spore to work you need to have grubs for it to live on. You can also treat with beneficial  nematodes; they are microscopic worms that will seek out the grubs and release a bacteria that kills them. Nematodes can be purchased in garden stores and online.

Don’t Create a Problem

Be proactive and utilize the tips above for prevention. You might not be able to stay grub-free for life but these techniques will give you a pretty decent shot. If you do have a grub problem make sure you take your treatment options seriously. Insecticides will also kill the good critters in your lawn when they’re busy killing the grubs you’re working to get rid of. Grubs can also be quite difficult to treat in the first place so don’t actively help create resistant super grubs by not following the proper procedures. Lastly, remember that when you apply insecticides that these chemicals can enter local creeks and bayous as storm water run-off. Insecticides can also be quite harmful to pets, birds, squirrels and all the other critters that make outdoor life enjoyable.

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