Unlike other common garden pests, who happily (and visibly) munch on our plants, grubs are a little more hidden. They live beneath the ground, snacking on the important organic matter that your plants need for nutrients and although they leave the foliage alone, their appetite for your plant’s roots is even more of a problem.
WHAT ARE GRUBS?
Grubs are about as unpleasant as their name suggests. They’re the larvae of June beetles, Japanese beetles, and Northern Masked Chafers that hatch as little white worms in the fall. They don’t stay too little for long, though, and they begin eating until they’re fat and plump, before digging themselves deep into the ground to hibernate. In the spring, they emerge and eat some more, before maturing into beetles. They then feed on other parts of your plant, before laying more eggs and starting the process again. Although beetles may be less harmful, they’re still responsible for the reproduction of larvae and should be treated, too.
SIGNS OF GRUBS
It’s often hard to identify a grub problem until the damage has already been done, usually later in the fall. However, there are a few signs of grubs that you can watch for.
You might notice some hungry visitors to your garden, like raccoons, skunks, and birds. If they’re coming around more frequently, it’s likely because they’re snacking on something. While that’s a great, organic way of getting rid of them, it can often be quite a nuisance and you should still investigate to see if further action is needed.
Since they chew up all the important stuff that ties your lawn down, grubs will leave your lawn feeling softer and spongier than normal. You might even be able to pull back the top layer of your lawn, like a sod, since nothing is holding it in place. If the problem goes unnoticed, patches of grass will eventually start to die.
PREVENTION OF GRUBS
The best way to prevent grubs is to use a preventative pesticide in May, continuously monitor your garden, and maintain a healthy lawn in the first place. Lawn maintenance isn’t just for looks - it’s for health, too!
Preventative pesticides will last much longer, doing its work over several months. They’ll kill off any grubs that are present at the time of spraying, while also lingering around long enough to kill the ones that hatch later on. Apply them in May to get the best handle on grub management for the rest of the season.
It’s important to irrigate your lawn after applying pesticides. Without water, the nitrogen in pesticide products can burn your grass in the summer heat. Water will also help the pesticide to trickle down further into the ground, covering a larger area and killing more grubs. An added bonus - the moisture will also draw the bugs up towards the surface!
Healthy grass with deep roots will be much better equipped to deal with pest problems. While it’s important to water after pesticide application, be careful not to over-irrigate on a regular basis. Grubs are attracted to the moisture, so constant watering does more harm than good. Give your lawn infrequent, but deep waterings to ensure their foundation is rooted deep into the ground, without attracting more pests.
Overseed your lawn in the spring, especially if it’s looking particularly thin. A sparse lawn provides a perfect environment for beetles to lay eggs. A thick, lush yard will not only look better but will also deter these pests from settling in.
Since grub problems are difficult to identify, we often don’t notice the issue until it’s too late. When signs of damage are already apparent, it’s most likely too late for preventative measures to address the issue.
It’s important to note, though, that if your lawn is well-cared for it can sustain a small population of grubs without issue. Going pesticide crazy after finding just one or two grubs is a good way to kill them, and also your lawn! As long as you keep up with mowing, watering, and fertilization, it should be able to support up to 5 grubs per square foot.
If infestation and damage are already evident, it’s time for a more powerful pesticide. Since the grubs will soon be burrowing deep into the ground for winter, it’s important to treat the problem as soon as possible. Remember, the ones that escape will emerge and lay more eggs next year!
Although it’s tempting to whack the pesticides to these gross little grubs, refrain from over-application. While we want to control the problem, we also want to preserve what’s left of your lawn! Always follow the directions given, applying the right amount at the right frequency.
As nasty and destructive as they may be, grubs are a pretty common pest here in Pennsylvania. When it comes to grub control, preventative practices and immediate action are crucial in keeping your lawn healthy and pest-free!