The annual rhododendron advice (in brief)

1) If you have a plant with silver leaves, it has nasty sucking insects called thrips. You can’t turn silver leaves to green again and the new foliage will get affected unless you do something to alter conditions. You can spray with an insecticide, though we prefer to advise alternatives. Open up around the plant to increase air movement (thrips don’t like drafts) and feed and mulch the plant to encourage increased vigour. If it keeps getting infected, take it out and replace it with a healthier option. There are rhododendrons which are better suited to warmer climates and are more resistant to silver leaves.
2) If you have a plant which has not set flower buds, the most common cause is too much shade. Because they set flower buds on their new growth (which is coming now), open up and let more light in as soon as you can. The other cause may be incorrect pruning.
3) Rhododendrons are surface rooting – in other words they go outwards not downwards. A healthy plant has a big mass of fine, fibrous roots which resembles old fashioned carpet underfelt. Mulching is good practice to keep these roots cool and nourished. Never plant them in wet spots where water can pond. They will die very quickly.
4) Deadheading is to stop the plant putting all its energy into setting seed. You don’t actually have to deadhead unless the plant is a seed setter, though it does make them look better.
5) Feed now as the plant goes into growth, if you feel it needs it. Rhododendrons prefer soils on the acid side (which our volcanic soils are here).
6) Moving plants around your garden needs to take place in autumn and winter, not now. Hard pruning of rhodos takes place in late winter or very early spring, not now.