Hydrangeas are not particularly popular with pests and vermin, but occasionally there are a few pests that cause trouble. Sometimes they infest the leaves, other times the pests wreak havoc on the flowers. Knowing which hydrangea pests like your plants and what to do about them can help you prevent an infestation or treat your flowers. Below, we’ll address the most common hydrangea pests that can threaten your plants and offer solutions for getting rid of them quickly and efficiently.
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Common hydrangea pests and their treatment
Pests, insects and vermin can take up residence on your hydrangeas and cause all sorts of problems. Here are the most common ones to watch out for:
Aphids attack new shoots
Aphids are small, green or black insects that feed on the plant sap and curl the leaves. To feed on the plant sap, these soft-bodied insects usually attack new shoots because they are much easier to penetrate. Ants on your hydrangeas may also indicate an underlying aphid problem , as ants like to feed on the honeydew that aphids leave behind. Try to solve the problem by first spraying the leaves with a stream of water. If that doesn’t work, you can spray your hydrangeas with a broad-spectrum insecticidal soap or a soap specifically designed to control aphids.
Beetles can destroy a plant very quickly
You’ll quickly notice these beetles with their shiny green and brown bodies nibbling on the flowers or leaves of your plants. Swarms of beetles can destroy an entire plant in a matter of days. So if you spot them on your hydrangeas, it’s best to remove them right away. The easiest way to do this is to remove the beetles manually.
Slugs are active at night
Slugs are another pest that can attack the leaves of your hydrangeas. Frayed leaf edges or holes in the leaves of your plants indicate a slug problem. Slugs are active at night and can be caught with slug traps. You can also spray the plant with soapy water to keep them off the leaves.
Control spider mites with neem oil
Spider mites gather on the underside of leaves and spin protective silk webs. As insects that feed on plant juices, they bite leaves. The spider webs are one way to detect a spider mite infestation; the other way is to look for yellow or off-white spots on the leaves. Spider mites thrive in hot and dry conditions. To treat a spider mite infestation, you can use natural remedies such as neem oil and pyrethrum. Ladybugs are a natural predator of spider mites. You can establish ladybugs in your garden and they will help you keep spider mites at bay.
Whiteflies are common pests
Another sap-eating insect that can damage hydrangeas is the whitefly. These are small, white-winged insects that live on leaves. Symptoms of whitefly infestation include yellowing of leaves and accumulation of honeydew (and ants as a result). In advanced cases, growth retardation and dieback may also be observed. Natural alternatives are neem oil or a homemade mixture of detergent, water and rubbing alcohol.
Keep hydrangea pests away
- Spacing when planting
Unless you’re planning a hydrangea hedge, don’t plant your hydrangeas too close together. Keep a distance of 20 to 25 inches between hydrangea bushes, depending on the variety. This will reduce the risk of pests and other diseases spreading from one shrub to another.
Water your hydrangeas at the base of the plant so that the leaves do not get wet, as this can cause disease . Water in the early morning hours so that the leaves have enough time to dry out if they have become wet. Since some insects thrive especially well in dry and warm weather, hosing down the leaves of your plants can help. However, make sure the spray is not too strong, as it can easily damage the leaves.
Remove dead, diseased leaves and flowers, especially to improve aeration, which reduces disease but also keeps some pests away. When pruning, be sure to disinfect leaves between cuts to avoid transferring diseases and pest eggs to other parts of the same shrub or to other shrubs.
- Preventive spraying
Spraying with organic agents such as neem oil can help prevent pest problems. Spraying your hydrangeas from time to time can help keep pests at bay and/or reduce their numbers.
- Visually inspect the leaves
Prevention starts with monitoring the condition of your plants. Visually inspect the leaves every time you water, and also take a look at the underside of the leaves, as this is where many pests make their home. If possible, remove hydrangea pests manually (e.g., slugs, beetles). If there is a heavy infestation of leaves or entire stems, you can remove them to prevent spread. Recognizing the problem and treating it in a timely manner will reduce the likelihood of severe damage and uncontrollable infestations.
- Natural predators
One of the easiest ways to control certain pest problems is to introduce beneficial insects into the garden that feed on those pests without harming the plants. Ladybugs can eliminate many pests , including spider mites.
- Natural pesticides instead of harsh chemical agents are recommended.