Japanese beetles can be an unforgiving pest in your garden. These shiny, incandescent-looking beetles can destroy whole plants very quickly, and are hard to battle if infestations become severe. Using a few different tactics you can control Japanese beetles, and save your precious vegetables, roses and other plants.

Where Do Japanese Beetles Come From?

Japanese beetles usually appear from late May to early August. The beetle will lay eggs in the ground in July and mostly die off by mid-August. In August the grub will hatch, then begin feeding on the roots of plants - mainly grass.

Japanese Beetle Grub Worm

When the temperatures begin to cool in October, the grubs will dig deeper into the soil and become inactive. Once the spring temperatures warm back up, the grub becomes active and once again feeds on plant roots. The grub has finished developing by mid-May, and emerges as an adult Japanese beetle.

How To Control Japanese Beetles

The best way to control Japanese beetles is to attack them when they are in the grub stage. A natural control of Japanese beetles is milky spore. Milky spore works best when applied to your lawn in the fall when the grub worm is hatching from the eggs. This naturally occurring spore is not harmful to humans or pets. The great thing about milky spore is that it naturally reproduces, killing more Japanese beetles each season.

Another natural way to control Japanese beetles is to let the moles get them. Moles are the natural predator of the grub worm. They can devour up to 50 grubs a day. Moles will only be present if grubs are present in your yard. Once the moles eat all the grubs, they will move on to another grub infested area. If you have a lot of moles in your yard, then you have a lot of grubs, too.

Moles Love To Feast On Japanese Beetle Larvae

Here are some ways to control adult Japanese beetles that you may find in your vegetable garden or yard:
    • Drown them - Use a small pail or cup and fill it half way with soapy water. Go out to the garden and simply knock the beetles into the soapy water.
    • Drown them, Part 2 - You can also hang a yellow pail up that contains water with two drops of soap. The beetles are sometimes attracted to this and will fall in the water.
    • Use Japanese beetle traps - You can set up a Japanese beetle trap that contains pheromone. Place these traps in the sun and far away from gardens. If you plant it near the garden, you could be luring the beetles straight to your precious plants. The beetles are very attracted to these traps, you could literally attract the whole neighborhood of beetles, that is why I stress keeping the traps at a safe distance from your vegetable garden.
    • Use plants that beetles do not like - You can also plant borders around your garden of catnip, chives, garlic and tansy. Japanese beetles do not like these plants and will try to avoid them. You can also plant clusters of these plants around vegetables that Japanese beetles love to eat.
Using these defenses and some hard-nosed determination, you can control Japanese beetles in your vegetable garden.

Control Japanese Beetles and Grubs