Rhododendrons are most commonly attacked by fungal diseases. One of the most dangerous is:
Phytophthora foliorum
A fungal disease characterized by brown spots on the leaves, stems, and roots. The leaves curl along the main leaf vein, and the base of the stems and roots rot.
Powdery mildew
White to gray powdery spots, blotches or felt-like mats form on leaves, green stems and buds.
Rust
Brightly coloured yellow-brown spores present in disease pustules on the lower or upper surfaces of leaves. The entire leaf blade gradually withers.
gray mold
It is a disease particularly dangerous for plants in autumn and winter.
Among the pests occurring on rhododendrons, the most dangerous for plants is:
- Otiorhynchus sulcatus, whose larvae chew holes in the leaf blades.
- Acleris Latifasciana, whose larvae destroy the leaf blades of the plant.
- Catotilia azaleella, which damage the leaf blade.
- rhododendron aphid, which sucks sap from young leaves and shoots, causing them to wither,
- snails., which damage the plant
The pest control includes using sprays with appropriate chemical agents. Significant help in getting rid of pests and diseases in rhododendrons include maintenance treatments, for instance deadheading, removing damaged old stems, raking and removing fallen leaves..