Rhododendrons are generally easy-care, evergreen plants that are known for their colorful flowers. If you have a beautiful shrub in your garden whose leaves are falling off, you may be worried. The rhododendron loses leaves in the summer for several reasons and here you will find out what can lead to this and how you can get your plant back in shape.
The evergreen rhododendron may shed a few leaves in summer, which is a normal process. However, if you notice that your shrub is continually losing a lot of leaves at once, it can be concerning. But if you know how to identify problems early or even prevent them, your plants have a better chance of growing healthy and happy.
Too little water in summer
If your rhododendron's leaves turn yellow and fall off, a dry spell may be the cause. The shrub has a fairly shallow root system and does not tolerate a lack of water. If there is no rain, you should water it regularly and keep the top layer of soil moist.
To prevent this, cover the soil with a 5cm layer of mulch to conserve moisture. It is best to use pine bark mulch as it creates the preferred acidic soil for the rhododendron.
Also remember that container plants require more water as they dry out more quickly on the hot summer days.
Waterlogging leads to leaf loss
The rhododendron needs moist soil to thrive, but it cannot tolerate waterlogging. Wilted, drooping leaves that eventually fall off are a sign that it is being watered too much and the roots are not getting the oxygen they need.
This often happens during heavy rains when the soil cannot drain properly or with potted plants whose containers do not have drainage holes.
Applying mulch can improve the soil structure in the garden to retain moisture and allow excess water to drain away. Also ensure a well-draining soil mix for the potted plants.
Excessive heat and sunburn
If temperatures get too high in summer, the plant can dry out and itsShed leaves. At air temperatures above 35 °C, the evergreen shrub should be regularly supplied with moisture. Once the rhododendron is potted, move it to a cooler location.
In extremely high temperatures and too strong, direct sunlight, sunburn can also cause the plant's leaves to fall off. They initially turn bright yellow with mild sunburn, and with more severe damage they develop brown spots and look dried out.
Add shade fabric to the garden on particularly hot days and move sunburnt potted plants to a shadier location.
Rhododendron loses leaves after transplanting
If you have yourRhododendron recently in the gardenhave implemented, it may take a while for the root system to spread. Even though you then water the plant, it cannot receive enough nutrients due to the compact structure of the root ball. This is why it gets drooping leaves, which it later drops.
To resolve this problem, use an irrigation system or soaker hose that delivers small amounts of water. If the root balls are well watered again, the leaves will soon recover.
Infestation by weevils
Your rhododendron may shed its leaves even if it is infested with weevils and their larvae. The adult beetle eats the edges of the plant's leaves, but the soil-dwelling larvae do the most damage because they eat the roots. This leads to wilting of the leaves and eventual death of the plant.
About thisto combat annoying pests, try to collect as many larvae from the soil as possible. A very effective method against weevils is treatment with natural nematodes.
Other pests that attack the rhododendron's lush foliage and cause leaf damage include lacewings and spider mites.
Watch out for fungal diseases
A fungal infection can also be the reason why the rhododendron loses its leaves. Phytophthora root rot is one of themost common fungal diseases, which affects the roots of rhododendrons.
If this is causing the leaves to fall off, you will see many signs of rot when you dig up the roots. Unfortunately, the disease has already progressed in the root area by the time you see the first signs on the leaves.
If a fungal disease is present, you should carefully dispose of the plant and replace the soil at that location.
To prevent fungal diseases, make sure that the shrub is not planted too deep. Otherwise it will be exposed to too much water, which can lead to root rot and promote the development of fungal diseases.
Also worth reading:Is your rhododendron not blooming? Find the cause!
