Boxwood Pests: What Are They And How To Fight Them?

Last updated on October 23rd, 2023 at 08:52 pm

Your boxwood should shine in all its glory. You spend a lot of time shaping the leaves and look forward to when the boxwood is at its best.

The joy can quickly be dampened if you discover pests. The boxwood may appear hardy, but even it is powerless against resistant pests.

Find out which boxwood pests there are and how to combat them in this clear guide.

Boxwood borer

Probably the most feared is the boxwood borer. The butterfly may fly around inconspicuously in the garden. But it lays its eggs on the boxwood and if the caterpillars of the boxwood borer grow, this poses a great danger.

Damage of the boxwood borer

The caterpillar of the boxwood borer is found on the boxwood shrubs from the middle of March. Then it is warm enough for the butterfly to become active again and also settle in your garden.

The caterpillar is only a few centimeters long. It is easily recognized by its striking coloration. The body is greenish and dotted with black spots.

Due to its high voracity, it causes considerable damage. The leaves and shrubs are eaten, so that in extreme cases the boxwood does not recover from it. Therefore, it is necessary to start with the appropriate control methods already at the first signs of boxwood borer.

Control of the boxwood borer

There are several methods available to get rid of the boxwood borer. If the infestation is still small, you can remove the caterpillars by hand. For safety, put on gloves to avoid direct contact. Otherwise, however, the caterpillars pose no danger.

For a larger infestation, you can use the power of a water spray. Pick up a garden sprayer and aim it at the caterpillars. The pressure will shoot the boxwood borers off the boxwood and they will no longer do any damage.

You can also use sprays to repel the box elder borer. Biological agents are available for this purpose and have proven to be effective.

The use of a boxwood borer trap is a good way to prevent an infestation in advance. The butterfly gets into the trap and does not lay its eggs on the boxwood.

As harmful as the boxwood borer may be, there are many different ways to control this pest naturally. Don’t delay, start taking the necessary steps early to protect your boxwood.

Boxwood leaf flea

In addition to the commonly known aphids, which are one of the nightmares of every gardener, there are also variants that specifically attack the boxwood. These include the small boxwood aphid. This is green, equipped with large wings and grows under a white waxy wool.

Damage of the boxwood leaf flea

Similar to the common aphid, the boxwood leaf flea also feeds on the sap of the leaves. It sucks the precious sap from the plant. These become bent in the shape of a spoon and often cannot recover from this.

The excretion of honeydew also attracts ants. Since ants are not very welcome in the garden, you should also drive away the boxwood leaf flea.

Fighting the boxwood leaf flea

The damage pattern of the boxwood leaf flea is very selective. It is hardly able to attack the health of the boxwood. Nevertheless, you should intervene if this pest spreads strongly.

The greatest danger comes from natural enemies. Spiders, ichneumon wasps or lacewings see the boxwood leaf flea as food. Keep your garden natural and attract these predators to drive the boxwood pests away.

Otherwise, you can still perform pruning to remove the affected shoot tips. With these simple measures, your boxwood should easily survive the infestation.

Scale insects

Scale insects also make a mess of your boxwood. You will often find species on the boxwood that are also found on rose bushes and fruit trees.

Damage of the scale insects

You can recognize scale insects by their brownish color. In case of heavy infestation, you will notice the numerous spots on the boxwood. They settle either on the shoots or along the leaf blade.

The scale insect is also one of the pests that sucks the sap from the leaves of the boxwood. When a major infestation occurs, this damage is so severe that the leaves are shed. The shoots may die and the boxwood will not leave a healthy impression.

Control of scale insects

Scale insects occur in large numbers, but they are not particularly fast. If you notice the first pests, you can prevent further spread with pruning.

If the infestation is severe, the only thing that will help is the application of a budburst spray. This can be applied at the end of May or in June to prevent the aphids from hatching. Use the agent early, so that it still develops its effect. Otherwise, the scale insects are so resistant that control will prove complicated.

Boxwood gall midge

Analogous to the boxwood borer, the larvae of the boxwood gall midge are also a great danger. These are about 2 to 4mm long and have an orange-yellow coloration. The midge lives for a few days in May or June. Clearly more dangerous, however, are the larvae that feast on the boxwood.

Damage of the boxwood gall midge

Once the boxwood gall midge has laid its eggs on the underside of the leaf, it does not take long for the larvae to develop from them. These usually appear in late summer. In the period of August or September you can see the yellow to orange spots.

The larvae are mainly located on the underside of the leaves. Often, the pattern of damage is also mistaken for a fungal infestation. Therefore, you should look more closely to better detect the larvae.

In the worst case, individual shoots can dry out. However, there is usually no further danger.

Fighting the boxwood gall midge

If you discover the hatched larvae, pruning is necessary. There may still be eggs on the boxwood, leading to hatching of the next generation in May or June.

The larvae are a ready meal for many a bird. Tits, for example, effectively decimate the number of boxwood gallflies.

If you want to protect your boxwood, you can use an insecticide. In most cases, however, this is not necessary and simple pruning will be sufficient to contain the infestation.

Spider mites

Originally from North America, spider mites now feel at home in homes. The small pests have been up to mischief here for a good 20 years and are difficult to identify with a maximum size of 0.5 mm.

Damage of the spider mites

If the spider mites can spread unhindered, the damage is correspondingly intense. These pests especially like warm and sunny locations.

There they feel comfortable and suck on the plant cells. This can be recognized by the fact that the leaves are covered with short streaks.

The leaves may appear lighter and if the infestation is too severe, the leaves are dropped. At the latest then fighting is necessary to prevent further damage.

Control spider mites

Spider mites are on the menu of some natural predators. These include lacewings, for example, as well as ladybugs. These decimate the infestation naturally and protect your boxwood.

Spider mites are also impressed by a rain shower. They are washed off the leaves and can no longer stay there. To effectively protect against spider mites, you can use an oil-based spray in the spring. By doing so, you will control the eggs and prevent the next generation from growing.

Shoot spider mite

If the shoots and leaves of the boxwood appear unnatural and twisted, the shoot tip mite is probably responsible. This type of mite shows itself not only by the outgrowth of galls, but only by the deformation of the leaves.

Shoot tip mite damage

The shoot tip mite is also one of the pests of boxwood that targets the sap of the plant. By sucking out the sap, the leaves curl up and become stunted. They twist and lose their striking green coloring.

Control of the shoot tip mite.

Among pests, the shoot tip mite is considered to be of little danger. Often the damage is purely visual, and the boxwood as such is hardly attacked. Likewise, the shoot tip mite hardly spreads and remains a local problem.

By regularly pruning the shoots, you can detect the animals and remove them selectively. This is sufficient to prevent further spread and protect the boxwood.

Keep the boxwood free from pests

To keep the boxwood free from pests, regular maintenance is helpful. By pruning and encouraging the boxwood’s defenses, most pests will not settle on it in the first place. On the other hand, if the boxwood is weakened, most pests will get to the sap more easily and spread more quickly.

Both in spring and autumn, you should make sure that there are no eggs on the boxwood, which will lead to the growth of the next generation.

With quick control, you will protect the leaves and get rid of the pest quickly. Then your boxwoods will feel at home in your garden and shine in full splendor.