There is nothing more heart-wrenching and frustrating to a rose lover than an infestation of Japanese beetles. These beetles can cause a lot of damage to rose bushes, and they can be a huge pain to try and get rid of.
But what are some methods that you can use to rid your rose garden of these pests?
One good way to get rid of Japanese beetles is to spray your garden with soapy water, focusing on the grass where the beetles lay their eggs. You can also remove the beetles from your roses by hand and dump them into a bucket of soapy water. You could use a natural or chemical insecticide, too.
These beetles can be formidable foes, so it is best to know all the tools you can use to get rid of them, so how else can you kill these pests once and for all? Let us find out.
How to Stop a Japanese Beetle Infestation on Roses
Japanese beetles can be a difficult opponent to face in your garden. These beetles can take over and spread quickly, easily destroying your plants in the process, especially your roses. So, knowing how to protect your roses and get rid of these pests is a must for any gardener.
Below is a list of ways to help you rid your garden of Japanese beetles; some of these ways are more effective than others, but you should use more than one method just to be safe.
1 – Pick the Beetles Off By Hand
The hand-picking method to get rid of Japanese beetles from your roses is a time-consuming task and does not sound like something you would want to do on your Saturday morning. But the hand-picking method is still the most effective way of controlling the Japanese beetle population and improving the health of your roses in your garden.
To make sure you get the best results when using this method, you should start in the early morning as this is when the Japanese beetles are the most active. To help you face the fact you will need to touch these crawling creatures, you should wear some gardening gloves.
Then before you start the process, prepare a bucket of water with some liquid dish soap mixed in, with the ratio being two tablespoons of soap per every one gallon of water. When you are ready, you need to pluck the beetles off your roses, ensuring that you do not crush or squeeze them in the process, as this could attract more beetles.
Once you have a gentle but firm grasp on the beetles, you can then drop them into the bucket of soapy water. This is one of the most ethical and humane ways of getting rid of Japanese beetles.
2 – Vacuum the Japanese Beetles
If you cannot bring yourself to touching and picking up the Japanese beetles by hand, then you can vacuum them up from your rose bushes using a small hand-held vacuum on its lowest setting.
This is an excellent way of picking the beetles off your roses without damaging them, and this is a helpful tool to have if you have any hard-to-reach rose bushes.
It is recommended that you have a one-handed vacuum dedicated to eradicating Japanese beetles on your roses as the vacuum could get quite dirty and littered with Japanese beetle body parts that you do not want to spread around your home.
3 – Use Insecticides
If you do not want to spend a lot of time dealing with the Japanese beetles on your roses, then a fast and easy way to rid your garden of them is to use insecticides. These are always a helpful tool to have in your fight against unwanted pests.
Insecticides have chemicals in them that will kill the Japanese beetles in your garden by attacking and shutting down the beetle’s nervous system.
You do need to be careful about the insecticide you use, though, as roses are a highly sensitive plant, and chemical insecticides can easily harm them. To help make sure the insecticide you want to use will not harm your rose bushes, you should apply a small amount to one section of one rose bush first.
Then you should wait 24 hours to see if the insecticide has any effect on your roses. You should also ensure that you get an insecticide that is not harmful to other beneficial insects like honeybees, which is needed for many aspects of human existence.
4 – Use a Natural or Homemade Insecticide
Suppose you are uncomfortable using chemical insecticides to get rid of the Japanese beetles on your roses. In that case, you can try a natural or homemade insecticide that will be less damaging to the environment. One of the safest and good natural ways to rid your roses of Japanese beetles is to use neem oil.
Neem oil is made from the Azadirachta indica tree, and it is a non-toxic oil. You must use neem oil when the Japanese beetle larvae are just about to reach adulthood, so you should start using it just before the beetles start mating.
To effectively use the oil, you should spread the neem oil on the soil that is near the afflicted rose bush. Both the oil itself and the oily residue will make their way to the beetles in the soil and cover the bugs as they leave the soil, killing them.
The neem oil that you spread over the soil will also permeate any of the developing Japanese beetle eggs that may be in the ground; this will kill the beetles before they reach adulthood. Neem oil is by no means the quickest method to kill the Japanese beetles, but it is a safer option that is still useful and will kill the beetles.
If you do not have access to neem oil but still want to use an environmentally friendly way of getting rid of the Japanese beetles on your roses, you can use plain soapy water. This is an excellent way to kill off the Japanese beetles without harming anything else in your garden, including your rose bushes themselves.
5 – Encourage Japanese Beetles Natural Bird Predators
Just like all other beetles, Japanese beetles have a natural predator that likes to eat them when they are at their larvae stage of life, birds. Many species of birds love to eat the fat and juicy larvae of the Japanese beetles.
So, an excellent way to help combat an infestation of these beetles is to encourage the birds to come and eat the beetles’ larvae, essentially stopping the beetle population in its tracks.
Not only will this help you control the population of Japanese beetles going after your roses, but this will also assist with the control of other pests like ticks.
You can make it easier for the birds to get to the Japanese beetle larvae, which will increase the effectiveness of this method. To do this, you can spray your entire lawn and flower beds with a soapy water mixer of two tablespoons of liquid soap per one gallon of water.
The reason you spay your entire lawn is that Japanese beetle larvae eat the roots of all garden plants, including grass, and they stay very close to the surface of the soil. The soapy water will force the larvae to the soil’s surface, where the birds can see them and get to them easily.
You should start this method in fall and late spring as the Japanese beetles will be in their larval life stage. You should continue spraying your lawn and garden weekly until you do not see more larvae emerge from the soil.
6 – Introduce Beneficial Nematodes to Your Soil
An excellent “green” option to help take care of the Japanese beetle population attacking your roses is to introduce beneficial nematodes to your garden’s soil. These are parasitic roundworms that will devastate any soil-dwelling pests, just like the larvae of the Japanese beetle.
These worms will roam around the soil, and once they locate a host, they will enter it. Then these microscopic worms will release a bacterium into the host that is deadly to the Japanese beetle larvae.
After they have killed their host, they will move on to another beetle larvae, which will reproduce during this process. You should introduce these helpful worms to your soil in late August to early September as this will produce the best results by attacking the next cycle of the Japanese beetles.
But these beneficial nematodes can be added to your soil at any time if you require them; just ensure you water the soil sufficiently.
7 – Use a Fruit Cocktail Trap
There are several commercially made Japanese beetle traps on the market today, but their effectiveness has been brought into question over recent years. Many gardeners have found that using the commercially made traps attracted more Japanese beetles to their roses.
From these accounts, a few scientific studies were done, which showed that these traps caught about 75% of the beetles, and they did attract a large amount of the beetles to the garden. This is why these commercially made traps are not recommended, but there is a trap that you can make yourself, that is.
The fruit cocktail trap is a great way to help deal with the Japanese beetle population. This trap can attract slightly more beetles to your garden, but it will kill them too, and it is a quick way to help remove active beetles from your roses.
Take a can of fruit cocktail, open it and ferment it by leaving it in the sun for a few days. Then you can place the fruit cocktail into a small bowl and place that bowl on top of a brick or two inside a bucket of water.
Place this fruit cocktail trap far away from your roses, and the fruit cocktail will attract the Japanese beetles, and the water in the bucket will drown them.
8 – Plant a Trap Crop
Roses are not the only plants that Japanese beetles love, so if you want to save your roses bushes and are alright with other plants getting slightly damaged, you can plant some of these other plants to create a trap crop.
These plants will attract the beetles away from your roses and into one specific area of your garden. Some of the best plants to attract Japanese beetles away from your roses are borage, African marigolds, knotweed, and primrose.
Once the beetles find and start attacking these plants, you can use another method, like the hand-picking method, to get rid of the beetles without your roses being harmed.
9 – Dry Out Your Garden Slightly
Japanese beetles prefer to live and go through their life stages in a well-watered garden with moist soil. They need the soil to be moist, especially for their eggs, as their eggs need water to develop correctly.
So, if your garden can take it, then a great way to lessen the attractiveness of your garden to Japanese beetles that are ready to lay eggs is to stop watering your garden, mainly your lawn, for a few weeks. You need to do this from late June until late July for this method to be effective.
10 – Take Good Care of Your Roses
Japanese beetles are attracted to rotting or overripe plants the most, so you need to ensure you care for your roses correctly and trim off any dead or dying or diseased leaves and stems. Keeping your entire garden healthy is an excellent way to help prevent Japanese beetles from being attracted to your garden in the first place.
If you have any trees or vegetables, or fruits in your garden, ensure that you oversee them and care for them. If you are growing any fruits and vegetables near your roses, ensure you harvest them on time. Roses are a Japanese beetle’s favorite foods, so even if another plant attracts them to your garden, they will go for your roses first.
11 – Plant Japanese Beetle Repelling Plants
To help rid your garden of pesky Japanese beetles, you can plant certain plants that seem to repel the beetles. It is not 100% proven that these plants work, but there is no harm in planting them to try and repel the pests.
Japanese beetles are a massive pain to gardeners, especially those with roses, as they are a favorite food of these beetles. These beetles can do a large amount of damage to your garden if you are left to breed, so you must start with your plans to eliminate them as fast as possible. It may even be worth your while for you to try multiple methods to get rid of them. Good luck!
Growing up with a mom who filled her home (inside and out) with all sorts of plants, Lisa got her start in gardening at a young age. Living now on her own with a home and yard full of plants (including an indoor greenhouse), she shares all the gardening tips she’s gained over the years.