The Content Of The Article:
- Step 1: Cut back severely affected box trees
- Step 2: Spray plants with the high-pressure cleaner
- Step 3: Treat boxwood with organic insecticide
Boxwood fans have had a new archenemy for about ten years: the boxwood bull. The small, immigrated from East Asia butterfly looks harmless, but its caterpillars are extremely voracious: they eat both the leaves of the boxwood and the bark of the younger shoots. Infested plants can therefore be so badly damaged that they only carry bare, dry shoots in the outer area.
Many hobby gardeners then make short work and separate from their evergreen darlings. But that does not have to be, because with a little patience and a few suitable measures, you get the problem under control - without the use of aggressive chemistry. How to do this, we explain here.
Step 1: Cut back severely affected box trees
If you discover the caterpillars of the boxwood on your box trees, you should first see how strong the infestation is. If after a short inspection already several webs become visible, you can assume that in your box tree several Zünslerraupen cavort. They are hard to spot because they are mostly inside the crown and well camouflaged with their green-yellow color.
Webs, kills and bitten leaves are clear indications of a boxwood conger infestation
If some shoots have already eaten or withered leaves, a vigorous pruning of the shrubs is essential: Cut all hedges, borders and trees about half their height and breadth back to the skeleton. This does not bother the plants, because the boxwood is very cut tolerant and drives easily from older branches again. Throw the clippings right in a garden bag. You can compost or burn it at a remote location in the garden. After pruning and further treatment, the boxwoods are fertilized with horny meal to aid the new shoot.
Step 2: Spray plants with the high-pressure cleaner
After pruning, it is important to remove as many of the remaining caterpillars from the box trees. This can be done quickly and efficiently with a high-pressure cleaner: Before starting, you should lay out a plastic fleece or a film web on one side of the border or hedge. So that it does not fly up under the pressure of the water jet, the side, which faces the hedge, is weighted with stones. Then blow your boxwood hedge from the other side at maximum water pressure with the high-pressure cleaner. Hold the spray nozzle quietly into the crown - the boxwood will lose some of its leaves, but in this way you will also catch most of the caterpillar caterpillars. They land on the foil and have to be collected there promptly, so they do not crawl back into the box trees. Just put the collected caterpillars far away from your box trees in the green meadow again.
Step 3: Treat boxwood with organic insecticide
With "Bio Zünsler- & Caterpillar-free Xentari", boxwood caterpillars can be combated in an environmentally friendly way
Despite the above measures, you should finally treat your box trees with an insecticide to eliminate even the last boxwood caterpillars. For example, a biologic that works well for this purpose is Naturen's "Bio Zünsler & Caterpillar Free XenTari". It contains as active ingredient a parasitic bacterium called Bacillus thuringiensis. The bacterium penetrates through body orifices into the caterpillar caterpillars, reproduces internally and secretes a toxic metabolic product that causes insect larvae to die. The preparation is applied as an aqueous dispersion with a conventional sprayer. Make sure you also wet the inside of the boxwood well from all sides. Incidentally, the preparation can be used against many types of pest insects and is also approved for fruit and vegetable crops in the home and garden.
The adult boxwood growers feed on the nectar of various flowering plants. Nevertheless, their frequent occurrence is an alarm signal
Buchsbaumzünsler make usually two per year, with very favorable weather conditions in the southwest and three generations. Experience has shown that the optimal periods for the use of Bacillus thuringiensis in late April and mid-July. Depending on the weather, they can also move forward or backward. If you want to be on the safe side, you should hang several yellow boards or special boxwood cinder traps near the box trees. When the first moths gather there, the drug is applied seven days later.