Grub Control

I fully understand that it's just the way life works, but it never ceases to amaze me how drastically perceptions change from childhood to adulthood. It's not just the big, important things either. You know, stuff like life, love, politics, and one-night stands. In fact, it's the way we grow to see all those seemingly innocuous things that floors me. In this case, I am of course referring to white grub worms. As a child, grub worms were awesome. I used to chuck them at the neighbor girls and then turn and run like hell before they could chase me down and pummel me (they were a couple years older). Even better than using them for pissing off the girls was using them as fish bait. They weren't very good for things like sunnies and perch, but grubs worked fantastically well for catching bullheads down at the river.

Like all good things, my romance with white grubs came to an end. While I still sometimes use them for fishing, these days I more or less just want to kill grubs, largely because the variety that is most prevalent, the Japanese beetle grub, is an introduced species. In my book, that usually means they should die. Not all grubs are Japanese beetle grubs though. There are two other really common ones: June beetle grubs and European chafer beetle grubs. I'm not gonna go into differentiating the species, because . . . who cares? What I will tell you is that grubs, whatever the species, are plump, fleshy, white to bluish white to gray in color, C-shaped, ¾” to 2” long, and have six legs, a brownish head, and a bad habit of damaging lawns. White grub damage is generally characterized by patches of dead or dying grass in the lawn. Lawn grubs like to eat the roots from sod, and that grass looks brown, wilted, and burned. It also rolls easily away from the soil. Grub worm damage is usually worst in the spring months of April and May when grubs move up to the soil's surface, and then again in September and October before they head back down. Perhaps the worst thing about lawn damage from grubs is that the grass rarely recovers. So unfortunately people just have to live with patchy grass for the season while they get grass grubs under control.

Behavioral Control: Control grub worms with a few adjustments in routine

First, figure out if grub treatment is even necessary. Pretty much every yard in North America has lawn grub worms from time to time. Luckily, most people's yards are never damaged to the point where grub worm control measures must be taken. You are more than likely not one of those people. Because those brown patches in your yard can be caused by a number of things, it's important to make sure it's actually grub damage before you go on a grub-killing spree. To do this, grab a shovel, pick a spot in your yard where brown grass meets green grass, and cut three sides of a 1 sq ft chunk of sod. Half of the square should be in the green, half in the brown, and you should cut down about 4 inches. Cut one line in the brown, the two side lines, and leave the line in the green attached. Once the three parts of your square are cut, try to peel the sod back. If the brown grass rolls back easily, that means the roots have been eaten and you have white grubs. You should also count any grubs you see. If you have 6 or more grubs per square foot, you have a problem.

Quit watering your lawn so often. I say this because grub worm eggs need plenty of moisture in order to hatch. If your lawn can handle it, don't water at all. If this isn't an option, only water when absolutely necessary. It's better to do a few deep waterings than lots of light waterings. This is true not only because eggs will be exposed to water less frequently, but also because this watering technique forces grass to grow longer roots which will enable them to withstand more grub damage before dying.

Consider letting moles live. While some critters like coons, skunks, and armadillos may do a little too much damage to lawns when digging for white grub worms to make letting them live seem like a good idea, other critters, like moles, aren't quite as bad. And they, my friend, can eat one helluva lotta grubs. So consider at least letting the moles live so they can continue killing grubs for you.

Don't worry about digger wasps. Digger wasps are those long, bluish black, scary-looking wasps that hover over your lawn in the summer. When you see these guys hanging around, don't freak out and start spraying Raid all over the place. These wasps are actually hunting for grubs. When they find one, they paralyze it, dig a hole in which to deposit it, and lay a single egg inside of it. When the egg hatches, the wasp larvae starts eating the grub, matures inside of it, emerges as an adult, and starts the process anew. Digger wasps are not aggressive and pretty much only ever sting people if handled or stepped on.

Habitat Control: Discourage and get rid of grubs by environmental changes

Keeping grass long and thick is a good grub worm control method. This works well because the beetles responsible for depositing the eggs that hatch into grubs prefer laying those eggs in areas with short, sparse grass. Set the deck on your lawn mower to keep the grass at least two inches long and remember to over-seed your lawn every spring and fall.

Keep grubs in check by repelling adults. I don't want to delve too far into controlling the adults here, but I do want to mention a couple things you can plant to help with repelling them. After all, fewer adults equals fewer grubs devouring your lawn and garden. Grow Japanese grub-repelling plants like larkspur, garlic, tansy, and red buckeye.

Pick up dead plant material from gardens. Because very young grubs will also eat decaying plant material, it is important to be consistent about removing dead leaves, twigs, and stems from garden areas.

Physical Controls: Fences, barriers, and exclusion devices for grub control?

Not bloody likely. I have not, through all of my experience and research, been able to discover a single physical control method for lawn grub control. Unless you're willing to bury a fine mesh screen several inches below your entire yard, you may be out of luck. I don't mean to say they aren't out there, and if you're aware of something I'm not, I'd be more than happy to update this article. Please just let us know.

Mechanical control: Kill grub worms without chemicals

Kill lawn grubs with aerator sandals. These little babies are a great choice for natural grub control. Aerator sandals strap onto your boots or shoes and have little spikes that penetrate into the soil. Not only do they aerate your lawn, they also kill grub worms quite efficiently. Studies have shown that wearing these little babies can reduce lawn grubs by as much as 56%. Sure, you'll look like an idiot river dancing across your grass, but you will have the satisfaction of knowing that you are a lean, mean, grub-killing machine.

Plow in the fall. Fall plowing works quite well for killing garden grubs. Keep in mind that the timing is important. Plowing should be done before the grubworms burrow too deep underground because of frost. Early October is a good time for this in the northern states.

Hand picking is another effective means of controlling garden grubs. I know it's not the most appetizing thought, but as you go through your garden with the tiller or when you're going through weeding, carry along a bucket of soapy water to drop grubs into. They're yucky looking, but they won't hurt you. If you don't want to touch them, get a kid to help. Pay him 5¢ per grub and forget everything you've ever heard about child labor laws.

Use beer as a grub killer. One easy way to help get rid of grubs naturally is to place beer traps in gardens and in areas of the lawn where grubs are prevalent. I know it seems like a waste of good beer, but if you dig a hole and place an old Cool Whip container or something of the like in that hole so that the top of it is flush with the ground and pour a couple inches of beer in it, you will trap some grubs.

Biological Control: Organic grub control

No adults = no babies. One of the best things you can do to control grubs is to control the adults. In general, this means controlling Japanese beetles. And since there is far more to that little task than I have room for in this paragraph, I will direct you to the article on Japanese Beetle Control. If it's not up yet, please accept my apologies and be assured that it will be there soon.

Kill grubs with Milky Spore. The use of Milky Spore is probably the number one most recommended method for white grub control. Milky Spore is the commercial name for the bacteria Bacillus popillae. This bacteria, once spread on your lawn, enters grubs and only grubs. Your beneficial critters are safe. Once inside the grub, the bacteria sets to work killing grubs. In climates where the soil is moist and at least 70°F, Milky Spore Grub Control can work its magic in as little as two weeks. If, however, you're not lucky enough to have those soil parameters, don't fret. It will still work for you, but it'll just take longer. The beauty of Milky Spore is that once it's established in your soil, it can provide you with season-long grub control for 15 years or longer.

Control grubs with beneficial nematodes. If you want to get rid of grub worms, the efficacy of beneficial nematodes is right up there with Milky Spore. They're perfectly safe for you, your pets, earthworms, and most beneficial insects. These little guys are nothing more than microscopic worms that get sprayed onto your lawn. Once there, they find their way into white grubs. Once inside, they emit a bacteria that more or less liquifies the grubs' innards so that the nematodes can devour them more easily.

Encourage robins and other birds to kill grubs for you. It's a well known fact that birds eat bugs and worms. Why not use them to your advantage? Place a couple bird baths around your yard to entice robins to stick around. While you're at it, put up some nesting platforms.

Neem oil kills grubs. Neem oil is a derivative of the neem tree. It works to kill grubs in several different ways. One way is that it acts as an insecticidal soap. This means that it blocks the insects' spiracles and doesn't allow them to breathe. Another way is that it is a growth inhibitor and disrupts the molting process. Yet another way, and the last that I will mention, is that it is an antifeedant. It makes the roots of the grass it is sprayed on taste bad that grubs will avoid eating it and starve.

Control white grub worms with pyrethrins. Pyrethrins are another natural grub killer, are derived from the chrysanthemum flower, and work well for killing grubs when used as a soil drench. While they are natural and are much safer than many other insecticides, I would only use them as a last resort. Pyrethrins may be toxic to humans. For more info on its toxicity, check out the EPA's web page on the subject.

Chemical Control: A few good grub insecticides

Kill grubs with Merit. Produced by Bayer, Merit 75 is among the best grub pesticides available commercially. The active ingredient, imidacloprid, acts on the central nervous system of grubs. While there are granules available, Merit grub control products are generally sprayed on lawns.

Use Dylox as a grub pesticide. Trichlorfon, an organophosphate, is the active ingredient in Dylox. Trichlorfon kills grubs by disrupting the regulation of certain enzymes in the nervous system that are responsible for keeping everything functioning properly. Dylox also comes as granules or as a wettable powder.

Let's not forget about killing grubs with Sevin. This product is also highly recommended for grub control. Its active ingredient is carbaryl. Carbaryl, like the previous two, kills grubs by messing with the nervous system of insects and is available as a dust, a liquid for spraying, and a granular insecticide.

Control white grub pests with Mach 2. This grub pesticide, available in granular and liquid forms, utilizes the IGR (insect growth regulator) halofenozide. Halofenozide kills grubs by causing them to shed their exoskeletons prematurely.

Last but not least, Scott's GrubEx. The active ingredient in this Scott's grub control product is chlorantraniliprole. GrubEx is applied to lawns with a spreader and, in order to activate it, one must then lightly water the lawn. According to the EPA, chlorantraniliprole kills grubs by interrupting normal muscle contractions.