In consultation with one of our customers in the Cotswolds we learned that they had always hoped to have a large, white flowering, specimen Rhododendron planted as a centre piece in their garden but the soil pH in the area was very alkaline and therefore unsuitable for Rhododendron’s which require acidic soil.
The Rhododendron we planted is a ‘Cunningham’s White’ and measured 3.5 metres high x 4.5 metres wide.
Our remedy was to build a Cotswold stone, circular retaining wall which matched the other walls of the garden and house and lined it with a membrane. The Rhododendron was then planted and backfilled into an acidic soil and peat mixture.
The many beautiful contorted clear stems and shapely evergreen leaf canopy made this Rhododendron an interesting all year round specimen tree, and to highlight this we installed under lighting, carefully buried in the soil at the base of the Rhododendron. Our thoughtful placement also complimented a similarly shaped Acer palmatum seen in the distance, an interpretation we like to call ‘Visual Echoes’.
Rhododendrons are a British favourite mostly because of their outstanding flower displays in Spring. Flower colours vary, the most commonly seen is the violet-purple native, Rhododendron ponticum as seen above.
Rhododendrons grow best in areas of regular rainfall and acidic soil with a pH of 5.0 to 6.0 that is moist, well-draining and rich in organic matter. If your soil is alkaline like the one in our storey above, you can grow and manage them easily in large pots or containers. When possible use rain water to irrigate because tap water, especially in hard water locations, contain high levels of calcium which is not good for Rhododendron because it reduces the acidity levels around the root system. Feeding with an acidic based fertiliser and topdressing with a loam-based ericaceous compost like John Innes will help.