Every year we face the battle of the beetles in the garden like clockwork Japanese beetles arrive in our garden in early June to eat to ravage everything they can find. If you ever think you are in control of life, start a garden, you’ll discover quickly how wrong you are. This year our Japanese beetle issue is on steroids, and easily the worst pest in our garden.
There are many methods of getting rid of Japanese beetles in your garden, but for the organic gardener, it can be hard to know what is safe to use. Here at Rosevine Cottage, we want to be good stewards of the land we have, so we don’t use chemical sprays or fertilizers. We only use natural products that are safe for us, our animals, and the land. We never want to put something on our crops that will pollute the soil or groundwater or harm the wildlife that happens into our yard.
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Wondering how to get rid of Japanese beetles without using harmful chemicals? We’ve compiled our favorite methods of naturally getting rid of Japanese beetles in your garden.
Identifying Japanese Beetles In Your Garden
You’ll know you have a Japanese beetle issue if you begin seeing plants with large holes bored in the leaves, or leaves stripped to the stem. Once they begin eating a plant it won’t take long before they devour the whole thing.
How to identify Japanese beetles
- Japanese beetles are about a ½ inch long.
- Their heads are a shade of green or even blue-green with a metallic hue.
- Japanese beetles will usually feed in small groups. Which means a group of them will descend on your plant together. Which is why they can become such a problem in the garden so quickly. Japanese beetles will usually start at the top of the plant and work their way to the bottom.
Japanese beetle facts:
- Adult Japanese beetles lay their eggs in early June directly in the ground. Japanese beetle larvae are known as a grub) can be identified by their thick white bodies, brown heads, and 6 legs.
- Japanese beetle grubs stay buried in the soil for roughly 10 months (over the winter) until they mature into beetles and come to the surface to feed.
- The average lifespan of the Japanese beetle is 40 days.
- Japanese beetles are usually the most active on hot summer days.
What Do Japanese Beetles Eat
Japanese beetles will sadly munch on just about anything their shiny little bodies land on. But they have some favorites, amongst our garden and orchard like:
How To Naturally Get Rid Of Japanese Beetles
We’ve implemented several methods to get rid of Japanese beetles and prevent future beetles from invading our gardens. Each of these natural ways to get rid of Japanese beetles we are confident are safe for our family and use in our own garden.
Organic Ways To Get Rid Of Japanese Beetles
Neem oil for Japanese beetles is a great method for organic gardeners to use on your plants in the place of things like Seven and other pesticides that are toxic. Neem oil denigrates in sunlight so you don’t have to worry about it seeping into the ground and polluting groundwater or poisoning animals. It can be used as a pesticide, fungicide, and even a miticide (I know that’s a lot of ‘cides).
We use this particular product on all of our plants and trees and have had great results, not just with Japanese beetles but squash bugs, aphids, mildew, black spot, rust, and many others. It’s kind of our go-to garden/orchard spray. Japanese beetles will ingest the neem oil, and then when they go to lay their eggs it will affect the eggs helping to prevent another batch of these pesky insects from attacking your garden next year.
- Rubber Gloves
- 3 Gallon Pump Sprayer
- 6 Tablespoons Neem Oil
- 4 Tablespoons Organic Dish Soap (we use Seventh Generation, but any organic/natural brand will do. You could also use a regular brand of dish soap but again we try to keep everything as natural as possible).
Put on your rubber gloves, measure soap and neem oil into a pump sprayer fill the rest of the way to the fill line with water. Secure lid and pump until you feel resistance. Begin spraying the plant, making sure you get the underside of the leaves.
DO NOT SPRAY if the temperature is above 90F, you should only spray early in the morning or at dusk. Neem oil is harmful to Bees if sprayed by the mixture. If you notice bees on your plant, wait until later or first gently spray down your plant with the garden hose so that the bees will move on and then spray with neem.
Make sure you always handle neem oil with gloves, and when spraying using a mask and goggles.
Diatomaceous Earth Japanese Beetles
Diatomaceous Earth can be used as a Japanese Beetle Killer, in your garden. Diatomaceous earth is made from the fossilized remains of aquatic organisms called diatoms. Their skeletons are made of a natural substance called silica. Over a period of time, they accumulated in the sediments of waterways. These silica deposits are now mined.
Diatomaceous Earth is not poisonous and doesn’t even have to been ingested for it to be effective. It works by causing insects to dry and die by absorbing the oils and fats from their exoskeleton. The sharp edges are abrasive and cut into the insect speeding up the process.
Simply sprinkle Diatomaceous Earth over your plants, we’ve found that using a finely grated colander works great for this. Remember to use a mask and goggles when using this stuff so that you don’t breathe it in or get it in your eyes. Don’t use when you see bees on your plant or it is very windy.
Japanese Beetle Traps
Japanese beetle traps can be effective in controlling the beetle population, but they also attract more beetles than would normally be in your yard. When using these be mindful of that fact and place them away from the plants you want to protect.
A word of caution, once when we tried using a Japanese beetle trap we barely had it out of the bag before being swarmed by Japanese beetles. We didn’t even get the trap set up before we were forced to drop it and retreat to the house.
How Japanese Beetle Traps Work
A Japanese beetle trap releases both a sex pheromone and a floral scent that attract adult beetles. The beetles fly into the trap where they either crawl or fall into the bag and are unable to get out. A coworker of Mr. Cottage would hang one in his chicken coop and cut the bottom out so the beetles would fall into the coop where his chickens would eat them.
You could also try these homemade Japanese beetle traps.
Soap & Water Method
The surest Japanese beetle killer is using gloves pick off the beetles and drop them in a container of soapy water. The beetles will be drowned and it ends the cycle. This method is also the longest but it does work.
Nematodes For Japanese Beetles
Introducing Nematodes or milky spore to your soil controls grubs, depending on the grubs in your yard you may want to introduce both. Milky spore may be the better of the two for Japanese beetles grubs, however in some areas nematodes may be the only one available. These should be applied to your soil once or twice a year.
Nematodes should be applied in the early morning or late evening, its best to apply after rain. Make sure they are not exposed to direct UV light when applying them to the soil or it will sterilize them. It doesn’t usually need to be watered in but should be applied to damp soil. 1 Teaspoon is sufficient for feet. Apply in rows 4 feet apart. The timing doesn’t matter as much on milky spore.
Other Ways To Get Rid Of Japanese Beetles
Some other great ways to naturally get rid of Japanese beetles are:
- Guinea Fowl – these birds are great for keeping down Japanese beetle and other insects like ticks populations down.
- Ducks – ducks are terrific foragers and are more gentle on your plants then chickens. They also will eat other harmful bugs like slugs out of your garden. Just make sure they don’t run out of bugs or they may start nibbling on your plants.
- Companion planting – Japanese beetles can’t stand catnip (also known as catmint), chives, chamomile, garlic, onions, leeks, and marigolds. You can try planting these plants that repel Japanese beetles around your garden.
- In the spring spray your garden with 2 tablespoons dish soap to a gallon of water, this will kill the grubs. You can spray this once in the spring, and again in the late fall before winter sets in.
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