Rhododendrons attract numerous insects. But pests also prefer the plant. Here you can find out what they are and how to effectively combat the pests…
- aphids
- Whitefly
- Vine Weevil Beetle
- bugs
- cicadas
Aphids suck on young shoots
Aphids are found on young shoots. Their sucking deforms the leaves. At the latest then the pest is visible. In addition, black sooty mold fungi attack the damaged leaves.
Whitefly sit and suck on the underside of leaves
Whiteflies or whiteflies attack the undersides of leaves en masse. When touched, they fly up immediately.
Countermeasures against lice:
Support the natural aphid killers in your garden. Such as wasps, ladybugs, ground beetles, hoverflies and lacewings. When using sprays, pay attention to products that are gentle on beneficial insects.
Vine weevil wanders over the leaves at night
The dreaded weevil, about an inch tall, wanders over the leaves at night and nibbles at the edges. Greater danger threatens from the larvae of the beetle. They develop from the eggs in the soil and eat roots, causing the plant to die off in a short time.
Countermeasures against weevils and larvae:
Chemical measures are of little use as the beetle only comes at night. Distribute rotten boards, tree stumps or old roots between the plants. The beetles hide underneath and you can dispose of them in the morning.
On the other hand, the larvae in the soil can be successfully combated. Roundworms, which are simply poured into the ground, have proven particularly effective. Note that the nematodes need soil temperatures of at least 10-12°C and even soil moisture.
Bugs use rhododendrons as a breeding ground
The rhododendron web bug or skin bug lays its eggs on the underside of the upper leaves in late summer. The bugs cover their brood with a visible droplet of black-brown feces. From May, wingless young bugs hatch. They appear as adult, winged animals in July. Hardy rhododendron varieties with felty hairs on the underside of the leaves are spared from the bugs!
Countermeasures against bugs:
The best time to spray to control larval growth is immediately after flowering. Make sure that the underside of the leaves are intensively wetted.
Cicadas kill rhododendron buds
What's grass green with conspicuous red stripes down the back? The rhododendron cicadas. From September they lay their eggs in the buds. Dangerous side effect: They transmit the fungal spores of the bud tan. These penetrate the buds during oviposition. The resulting dark-colored buds do not fall off, but are covered with a veil of fungi in spring.
Countermeasures against cicadas: Not the fungus but the cicadas
can be successfully eliminated. Most effective by regularly spraying the undersides of leaves early in the morning. While the insects are still cold and dormant. The dark, fungal buds break out from February and dispose of with household waste.
tips and tricks
When using spray, note that the liquid does not stick well to the smooth rhododendron leaves. Add a few squirts of dish soap to the spray to break the surface tension of the water.