Why are the rhododendron leaves eaten? Are you wondering what causes this damage and how to save your plant? Can a cicada infestation be the cause and what can you do about it?
The beautiful, evergreen rhododendron is every gardener's pride. The real eye-catcher develops its full splendor from May and brings lots of color in summer. But if you notice that the rhododendron leaves are eaten, this damage is probably caused by cicadas.
The rhododendron is very popular for its colorful colors and the variety of sizes and leaf shapes. It is a relatively easy plant to care for and the most common pests and diseases can be easily avoided by providing the best growing conditions. Many gardeners wonder why rhododendron leaves are eaten and why their plant has so many black, dead flower buds. The cause of this problem is often not frost damage, but rather a cicada infestation. The colorful rhododendron leafhoppers mainly attack the plants in July and can damage them if effective measures are not taken in time.
What are cicadas and how do you recognize an infestation?
The very small, green-red pests are often found on the underside of the leaves and cause very small holes in the foliage. They suck the plant sap and eaten leaves with silver-colored to white-yellow spots are the first visible signs of infestation.
Also read:Rhododendron gets yellow leaves in autumn: 3 possible causes
However, the greatest damage begins in late summer when the adult insects lay their eggs in the buds of the rhododendron and puncture small holes in the buds from which they hatch the following spring. The larvae collect on the undersides of the leaves from the end of April and are fully mature by July.
They are known to spread a fungal disease that often...black budsand leads to impaired flowering. The fungus Pycnostysanus azaleae dries out the flowers and they die. For this reason, rhododendron leafhoppers are fiercely combated by many gardeners.
We should also mention one advantage of cicadas infestation. A few cicadas can be of great benefit to the plant. Because by sucking they transmit small amounts of bacteria, viruses or fungi that are necessary for young plants to develop resistance to possible damage.
It is still recommended to remove the affected flower buds as quickly as possible in spring and destroy them so that the fungus cannot spread.
How can you fight them?
If your rhododendron is infested with leafhoppers that have caused extensive damage, the easiest method of control is to collect the pests by hand. You can also spray the plant several times with the garden hose to remove the adult insects and larvae.
Rhododendron leaves eaten: drive away cicadas with vinegar
Rhododendron leafhoppers do not tolerate an acidic environment, which makes the use of vinegar very effective against the small insects. You can make a simple solution of one part vinegar to five parts water and spray the plant completely at the first sign. It is best to do this in the morning when the cicadas are not yet very active and the rhododendron can be easily treated.
Get Rid of Cicadas with Neem Oil
You can effectively combat leafhoppers with a neem oil solution by gently applying it to the infected plant. The treatment should be repeated several times so that all insects come into contact with the home remedy.
First, mix two liters of water with a teaspoon of dish soap and then add 10 ml of neem oil. Spray the affected plant, paying particular attention to the undersides of the leaves. The ideal time to combat with this product is the early morning hours when the cicadas are still motionless due to the cooler temperatures.
Keep away with yellow signs
Adult cicadas can be prevented from laying eggs by placing yellow panels in close proximity to the rhododendron and between the plant's branches. But replace them regularly to catch all insects or at least reduce the population.
The yellow signs are also very helpful for early recognition of an infestation.
Prevent cicada infestations
If you take some preventative measures, you can prevent the infestation in time.
When growing rhododendrons, make sure there is enough space between the plants. Not only will your rhododendron have enough space to grow and be more resistant to disease, but you will be able to combat pest infestations much more efficiently and avoid spreading them.
Water the rhododendrons toohomemade, diluted nettle manureto keep the insects away. Mix some of the natural control agent with the irrigation water and water the plants regularly with it.
Also worth reading:Is your rhododendron not blooming? Find the cause!
