Rhododendron pests and diseases: how to recognise them

Q: Which rhododendron problems need quick action?

Grey mould: Small, almost translucent spots that turn brown and water-soaked; affected tissue goes soft, dark and dies, and buds and flowers shrivel. Honey fungus: Peel back the bark at the base — a creamy-white, paper-thin sheet of fungus between bark and wood that smells strongly of mushrooms confirms it; the bark at the base may crack and bleed.

Rhododendron

The pests, diseases and disorders recorded for rhododendron in our library, each with a photo and its first symptom. Every page has the full list of symptoms, organic and chemical treatment and prevention.

At a glance

Problems in total	4
Pests	2
Diseases	2
Need quick action	2

How to grow rhododendron · All pests and diseases

Pests

Scale insectsSticky honeydew on leaves or on surfaces below the plant, often with black sooty mould.Photo: BARAKAT2011, CC BY-SA 3.0, Wikimedia Commons
Vine weevilDull black, pear-shaped weevils about 9 mm long with dirty-yellow flecks, feeding at night; they cannot fly.Also called: black vine weevilPhoto: Opuntia, CC BY-SA 3.0, Wikimedia Commons

Diseases

Which rhododendron problems need quick action?

These spread or do lasting harm fast; check the plants and start treatment the day you see them.

Grey mould: On strawberries, grapes and other soft fruit a soft brown rot, often as the fruit ripens; on gooseberries whole branches die.
Honey fungus: Black or brown root-like cords ("bootlaces") on the roots and in the soil, mostly in the top 15 cm.

Plants with many of the same problems

Which plants each problem affects: sources

The links between these problems and the plant were checked against these pages.