Organic pest control for Japanese beetles
Just as in any garden, butterfly gardens are susceptible to a wide range of destructive pests. Japanese Beetles present a particular challenge, because they can quickly skeletonize the leaves of plants, causing them stress….but using pesticides could threaten the butterflies and caterpillars you’ve worked so hard to attract.
To control these pests, you will need to know what they and the damage looks like so you can pinpoint your problem.
Japanese Beetle Damage
Japanese beetles are small, metallic beetles with shiny green bodies with copper colored wings. They feed on over 300 different types of plants, so avoiding any of these plants can be a challenge. These beetles tend to feed on leaves in between the veins of the leaves and favor hot weather and gravitate towards plants in full sun.
Roses, flowering cherry and crabapple, zinnias, linden, birch, elm, and marigold, among other ornamental plants, are especially susceptible to Japanese beetle feeding.
Butterfly bushes, zinnias, and salvia are some of the potential targets of these bothersome beetles in your butterfly garden.
Diseased or undernourished plants are also more likely to attract Japanese beetles, as well as overripe or diseased fruits. Focusing on the health of your plants and picking up any fallen fruit can help deter a Japanese beetle feeding frenzy.
Here are some low-impact, chemical free options to get rid of Japanese beetles in your butterfly garden.
Butterfly-Safe Control Methods
There are many methods to control and reduce Japanese beetle damage without using conventional pesticides. They might take a bit more work, but you will be rewarded by fewer pests without endangering the wildlife you want to attract.
- Handpicking: If you only notice a small population of beetles, or you just have a small area of plants, picking these beetles off can give you fairly good control. Shake the beetles off the plants into a bucket of soapy water, preferably in the early morning when the beetles are slow moving. Removing the beetles from the area is crucial, because beetles attract more beetles, and allowing them to accumulate will only lead to a bigger population.
- Biological controls: Birds tend to avoid beetles because their hard shells make them difficult to eat. However, toads, moles, shrews, and skunks are known to eat beetles. They can help but won’t offer a lot of control.
- “Decoy” crops: When planning your garden, you can choose to plant certain varieties of plants that will attract Japanese beetles. This sounds counterintuitive, but if you place these plants away from your butterfly garden, they will be more likely to leave the garden alone and focus on their more preferred plants. White geraniums, evening primroses, and others create a “decoy” away from your prized plants. You have to be willing to let these plants be damaged, however.
- Resistant plants: Planting resistant plants over other varieties will also make your property less attractive to the beetles and they may (hopefully) seek a different yard or garden to land. Red maples, redbuds, dogwoods, holly, magnolia, spruce, lilac, yew, arborvitae, nasturtium, asters, milkweed, violet, begonia, coreopsis, hostas, and forget-me-nots are just a few of the many resistant plants you can plant.
- Milky Spore: Destroy the grubs, miss out on the beetle invasion! This has been reported by many gardeners to be one of the most effective solutions over time and one application can last for decades! Click here for more info on Milky Spore
- Pheromone traps: These are a very popular option, but can be a bit complicated. They use a scent or pheromone lure to attract the beetles to the traps.
The problem with traps is they can end up bringing more beetles to the area, rather than attracting beetles directly to the traps. If you choose to use these devices, do not place them near your garden or plants you want to protect, but on the edges of your property.
Keep in mind that seeing Japanese beetles in your garden is probably inevitable. Controlling them at first sight will likely go a long way in keeping your garden plants save from beetle-biters.
Trying one or more of the steps above should help you achieve Japanese beetle control, leaving your garden plants free for the butterflies.