Buxus sempervirens, which is known under the common name Buxbaum, is one of the popular ornamental trees for hedges and topiary. However, during the growth phase it can happen that the parts of the plant are infested by pests.
The box tree moth is a feared pest
box tree moth
The moths lay their eggs inside the box trees. Their caterpillars are green in color with a black pattern. They develop cocoons and start eating the leaves from mid-March, working their way from the inside out and leaving the veins of the leaves standing. They feed on the green bark on the shoots and gnaw their way through to the wood. The branches dry up and die.
You can do that
Timely action increases the chances of success of manual control methods. Blow out the wood with a pressure washer (€119.90) to minimize infestation by box tree moths. Wrap the crown in dark foil so that the pests die in the heat. Severely infested shrubs must be cut back vigorously. A treatment with threadworms, which you put in water and distribute with an atomizer, helps here. Biological preparations with the bacterium Bacillus thuringiensis prove to be helpful in the early stages.
Boxwood flea
Fleas on boxwood appear between May and June and lay their yellowish eggs under the outer scales of the buds by July. The egg clutches overwinter so that the larvae hatch in the coming spring. They ensure that young leaves curl up and form a shell. This spoon-leaved appearance can be seen in densely packed and young leaves on shoots that are in the process of growing. The sucking activities produce galls on which you can observe wax excretions.
What helps
If you recognize an infestation early, cut off the affected shoot tips generously. If large populations have formed, combating them with preparations that contain neem oil makes sense. Opt for less susceptible varieties such as 'Elegantissima' or 'Blauer Heinz'
Boxwood spider mite
Since spider mites prefer dry and warm weather, they are rarely a problem outdoors. However, the pests can spread during the hot summer months. The leaves have streak-like light spots, with young foliage being particularly affected. If the infestation is severe, the leaf surfaces appear mottled. Rarely does it happen that complete branches are surrounded by webs. Encourage natural enemies such as predatory mites. Spraying with preparations containing rapeseed oil clogs the animals' breathing openings, causing them to suffocate.
Make and use rapeseed oil preparation:
- Mix one liter of water with 250 milliliters of rapeseed oil
- Spray infested trees twice a week
- Do not omit the undersides of the leaves and the inner shoots
tips
Under favorable conditions, up to six generations develop in one year. Maintain a humid microclimate, as wet conditions drastically reduce stocks.