How to control Japanese beetles naturally

June 7, 2013 | By | More

Japanese beetles

Japanese beetles LOVE roses!

Every year, I learn a thing or two (or a dozen!) about garden pests that can wreak havoc on my prized perennials. And believe me, there are many! My first year with a garden, I noticed that the leaves on my hosta were starting to look like Swiss cheese. I actually didn’t notice it until it was really bad. After days of investigation and research, I discovered slugs…gazillions of them happily munching on the now lacy-looking leaves.

Although it was too late to put a dent in their populations that year, the next year I was ready at the beginning of the season. I sprinkled Sluggo, a natural slug control that’s organic and safe, around my hostas in late May and was relieved to see that it was very effective. My hostas were lush and beautiful that year.

I had a similar experience last year when, starting in June, I noticed holes in the leaves and flowers of my very hardy roses, and my hardy hibiscus, AND the Rose of Sharon, AND the crape myrtle! Once again, I started examining the plants to find the culprit, and it was much easier this time around. I spotted two of them…one on top of the other in a frenzy of lust, procreating right there out in public. Japanese beetles, the bane of gardens everywhere.

These guys can appear seemingly overnight and in swarms, decimating what’s taken months to grow and bloom. They’re quite handsome actually with their iridescent colors and striped patches along the side.

Organic Japanese beetle control depends on first understanding their life cycle because it provides two opportunities for action.

Life cycle of Japanese beetles

Japanese beetles start out as grubs living in the soil. They hatch from eggs that are laid under the surface of the soil by adult beetles throughout the summer. The immature grubs feed on the roots of grass and other plants and can do significant damage to a lawn. Besides the direct damage from the grubs, their presence in the soil also attracts skunks and raccoons to your yard. These guys will dig up your yard leaving craters behind to unearth and eat the grubs.

The grubs grow quickly and will burrow deeper into the soil as winter approaches. They become active again in the spring, and starting in early summer (June in my yard), they emerge as hungry adult Japanese beetles that are ready to indulge in shameless public fornication and gluttony all over your favorite plants.

Japanese beetles

Let’s get this party started!

Control them naturally

If you know me or have been frequenting Tomato Envy, you know that I’m not in favor of garden beauty with a high environmental price tag. Gardens should enhance, not harm the environment, and part of that means learning to coexist peacefully with a controlled pest population and accepting a little plant damage here and there.

That said, it is very important not to let Japanese Beetle populations grow because live beetles emit a pheromone that attracts more airborne beetles to your yard for wild parties. They mate quickly and produce thousands of eggs and would-be grubs.

The first step of Japanese beetle control is to minimize the grubs in your yard. The best and safest way is to use milky spore, which is suitable for organic gardening. It’s a white powder that contains spores that will sink into your soil where they’ll be ingested by the grubs. Ultimately, the grubs will fall ill and pass away and the spores continue to multiply exponentially in your soil, affecting more and more grubs over time.

One proper application of milky spore (follow the instructions on the box!) will control grubs for ten years!

Grub control will help. But, the adult Japanese beetles are airborne and will fly to areas where they “smell” other beetles. It’s not possible to completely eliminate them. But, if you can believe it, regular handpicking of the beetles is highly effective in preventing more from showing up. Japanese beetles are groggy and sluggish in the morning. Last summer, several times a week, I went outside with a small pail filled with soapy water. I would either shake the branches of my shrubs over the pail or just pick them off individually and drop them in.

If you’re squeamish, just wear gloves. The beetles are harmless – they don’t bite or sting and they cannot eat you!

Whatever you do, avoid commercial traps for Japanese beetles. These traps simulate the pheromones of the beetles and attempt to lure them to their death. The fact is, these traps actually attract more beetles to your yard or neighborhood – even more than would have naturally been there.

Encourage your neighbors who garden to follow these natural Japanese beetle control practices too, particularly with the milky spore. Less grubs in your neighborhood means fewer adult Japanese beetles and more beautiful gardens.

Tags: , , , ,

Category: Flowers, General, Home and Garden

Leave a Reply

Read previous post:
dividing perennials
Dividing Perennials: Boost Your Garden ROI

There are lots of expensive hobbies out there, like learning to fly a Cessna or extreme ice climbing.  I never...

Close