Mulching Rhododendrons. Plant on the sheltered side of a windbreak. Use organic matter such as leaf mould garden compost bracken peat pine needles composted wood chip bark or very well rotted manure and apply as a 3cm deep layer which will act as a sponge and retain water on dry soils during summer months.
Pine needles also make an excellent azalea and rhododendron mulch. These little brown wounds on the undersides of this azalea plant are the result of sucking damage by lace bugs a common pest of. The best mulch for a rhododendron is one using pine needles.
For milder climates maintain a good layer of mulch and make sure not to plant it in openly windy areas or low spots.
The first of these benefits is that mulching conserves moisture by physically holding it and releasing it slowly to the soil beneath. On the other hand mulching your rhododendron helps keep the roots from freezing in the winter. Use organic matter such as leaf mould garden compost bracken peat pine needles composted wood chip bark or very well rotted manure and apply as a 3cm deep layer which will act as a sponge and retain water on dry soils during summer months. If the mulch touches the trunk of the shrub the moisture in it can lead to rot.