If you notice holes in the leaves of your hydrangeas, or entire branches are missing, you may have a pest problem. Although most pests do not bother hydrangeas, there are some common ones that gardeners have to deal with from time to time. Here are the most common pests:
Aphids on Hydrangeas
Aphids are very small, soft-bodied insects that insects that pierce plant stems with their tiny mouths to feed on plant sap. These insects will typically be attracted to new growth, as it is easier to pierce the stem wall to get to the sap. An easy way to tell if aphids may be the problem, is by looking for ants. Ants love to feed on the honeydew substance left behind by aphids.
Treating Aphids on Hydrangeas
The first line of defense to to spray the areas where you suspect aphids are located with a strong water jet from the hose. Be careful not to spray so strong that you damage the plant. Also, if you have black spots on your hydrangea, we do not recommend this method as it will cause extra moisture on the leaves.
If a strong stream of water isn’t an option or working, you can spray an insecticidal soap solution on the leaves and stems. Use as directed on the bottle.
Japanese Beetles on Hydrangeas
You can’t miss these large beetles when they arrive in the dead of summer. These have shiny green and brown leaves and will eat through hydrangea leaves and many other plants in your garden. If you do not remove these fast, swarms of beetles have been known to take down entire plants in a matter of days. While this rarely kills the plant, it leaves it looking very unsightly the rest of the year.
Treating Japanese Beetles on Hydrangeas
It is best to do this in the morning when the beetles are moving the slowest. We recommend hand picking these beetles and putting them into a bucket of soapy water. Or you can crush them with your fingers as some gardeners get a sadistic pleasure when when dealing with these demonic insects.
There are mixed reviews on getting Japanese beetle traps that use pheromones to catch the bugs. The traps do work well, but some gardeners say that it attracts even more Japanese Beetles from surrounding areas.
Slugs on Hydrangeas
Slug, or land slugs, tend to attack young hydrangeas. You can tell if they are a problem when you see ragged edges and holes in the hydrangea leaves. The best time to try and find the slugs actually on the plants is at night. Slugs don’t prefer to eat hydrangeas, they prefer to eat old decaying material. However if there is no other food, they will munch on the leaves and leave your hydrangea looking sad pretty fast.
Treating Slugs on Hydrangeas
You can spray the plants with soapy water. Use a teaspoon of dawn or joy dish soap with a quart of water in a spray bottle. Spray the leaves, branches and the ground beneath the plant. That should deter them from coming back. If that does not work, you can lay slug traps around the plants.
Spider mites on Hydrangeas
Spider mites are tiny insects that are almost invisible to the nake eye. These tiny bugs live underneath leaves of the hydrangeas, where they spin protective silk webs. The webs are the best way to tell if spider mites are the problem. These insects will puncture the plant cells to feed, which damages the leaves.
Treating Spider Mites on Hydrangeas
Ladybugs are the best way to control spider mites. We recommend planting other plants that will attract ladybugs around your garden. Or you can also purchase ladybugs to release in your yard. That is the best way to control spider mites without having to resort to using insecticides, which may harm other insects that are helpful to have in your yard.
Spider mites like hot and dry conditions as well. So you can often prevent the bugs from making a home on your hydrangea by keeping the plants well watered throughout the summer.
Another question we often get is Are Hydrangeas Deer Resistant?
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