It has been a very special month for the Rhododendron, Camellia and Magnolia Group (RCMG) as they celebrate their 100 year anniversary. As part of these celebrations RHS Garden Wisley hosted the centenary event on the 7-8 May, which showcased the top 100 rhododendron varieties and included a competition for best bloom.
Delicate pink Rhododendron schlippenbachii was the resounding winner – see the Rhododendron, Camellia and Magnolia Group website more information. There was also a grafting demonstration and a chance for visitors to vote for their favourite flower. The curatorial team led tours around Battleston Hill to highlight our marvellous rhododendron collections.
Behind the scenes the woody team worked hard to get Battleston Hill looking its best for the event. In the weeks leading up to the centenary show the whole team, including our students and volunteers, could be found mulching and weeding around the hill.
Although mulching smartens up the beds, the main reason we mulch our rhododendrons, camellias, magnolias and hydrangeas is to prepare them for the long summer ahead on our dry, sandy soil. All of these trees and shrubs prefer moisture-retentive soil, so we place a 7.5cm (3in) layer of mulch around the base to slow down evaporation, which can be quick in spring. Mulches can take all sorts of forms, from slate chips to shredded bark and ordinary garden compost. This spring we’ve been using composted bracken sourced from the New Forest, which is ideal for ericaceous plants such as rhododendrons and camellias.
Although the event was a few weeks ago, Battleston Hill still looks dazzling. Many rhododendrons are only just coming into flower and one of my favourites is still in bloom – the Loderi Group rhododendrons. These large rhododendrons produce heavy clusters of huge flowers which smell absolutely amazing – somewhere between a melon, a strawberry and a vanilla pod. Coupled with the fresh greens and reds of the Japanese maples (Acer palmatum), lush leafy hostas, scented wisterias and the famous, pink-leaved Toona sinensis 'Flamingo', Battleston is definitely an area of Wisley you must see!
Find out which rhododendrons have received an Award of Garden Merit (735Kb pdf)
Read about growing rhododendrons on alkaline soils