Japanese beetles have descended upon many Front Range communities. These exotic pests love many of our favorite plants, including roses, Virginia creeper, sunflowers, and green bean plants. But before the adult beetles wreak havoc on plants, leaving behind lacy skeleton of leaves, their white grubs are busy at work chewing on our turf roots.
If your lawn is looking damaged, it could be due to any number of causes including heat stress. But if you are seeing Japanese beetles in your yard, they could be laying eggs in your turf and affecting its health. Luckily, some of the same techniques can help with either cause. Mow your grass higher—it promotes deeper root growth and helps turf manage the heat. Healthier roots can better withstand the grubs’ destructive behavior, so any practices that promote turf health make your lawn less susceptible to damage.
As for the adults in your plants, the best control is handpicking them and dumping them in soapy water. If you can’t control them this way, you can speak with a landscape professional about insecticides that might help. Traps are not recommended, as they have not been shown to reduce beetle damage. In fact, the lure that attracts the beetles to the traps is likely to invite even more beetles into your landscape than they capture, according to USDA, thus increasing the damage to plants.
Experts say that the only way to avoid losing plants to these pests, look for plants that don’t attract them, like lilacs, hydrangea, and pines. Again, your local garden center or landscape professionals can help you find the right plants for your conditions that won’t bring more beetles around.