In 1919 when the Gardens at Exbury were first laid out by Lionel de Rothschild it very soon became apparent that although the pH of the soil was very favourable for the cultivation of Rhododedrons the climate was far from perfect and for this we have to thank the Isle Of Wight. Being on the very edge of the New Forest and being virtually at sea level the Island casts a rain shadow and creates a phenomena known locally as the 'Exbury Bowl'. As a consequence any weather front approaching from the south or west is deflected and it may rain as close as by Brockenhurst, Lymington and Lyndhurst and yet bypass us completely.
Lionel overcame this problem by building an enormous water tower which holds 50,000ltrs and he also laid over 20 miles of pipe in order to irrigate his precious plants. The network of pipes is still very much in use but the water tower has been superseded by a borehole. Rhododendrons come from some of the wettest places on earth, (some experience up to 2m of rainfall a year), and they rely on summer moisture to set their buds for the following springs display and also reducing the chance of problems caused by stress. Because of this our team at Exbury spend most of the summer irrigating our prize collection in order to ensure a repeat of the fantastic spring show we had this year.
Spring feels like a distant memory as temperatures this week have soared above 30 degrees. This may be difficult for the gardens team but many of the plants in the herbaceous border come from the drier, sunnier parts of the world feel very much at home. This is currently reflected in the fabulous show of Knifophia, Hemerocallis, Astrantias and Achillea. With the help of our volunteers deadheading, staking and weeding the borders will continue to improve until their zenith in a month or so's time.
Although the majority of Rhododendrons flower in the months of April and May there are a few notable exceptions. Exbury with its long and proud tradition of Rhododendron breeding has spent a great deal of time and effort trying to increase the flowering season. This has been achieved using several wonderful late flowering species as parents, this often meant storing the pollen over an extended period of time which was no mean feat the best part of 100 years ago! Some of these fine hybrids are still to be found though out the gardens and help to punctuate the various midsummer shades of green. One of the main parents of these late hybrids is the magnificent form of Diaprepes known as 'Gargantua' that grows throughout the garden. It is one of the parents of both 'Isabella' and 'Bustard' which both have the gentle perfume, large upright habit and huge trusses of white blooms of its parent. At the other end of the scale the satin like textures of the dusky red flowers of 'Impi' make a welcome sight. Being much smaller in stature 'Impi' makes a ideal garden plant even in the smallest of gardens.
It was Lionel's ambition to grow every single rhododendron species in the garden at Exbury and to include the alpine species he embarked on the building of the Rock garden. It was the last bit of the gardens to be laid out and was never completely finished due to the outbreak of WW2 and the subsequent sudden death of Lionel. As in many other gardens Lionel found that the shady conditions that suit the larger rhododendron species didn't apply to the smaller alpine species due to the vast range of habitats they enjoy in the wild, (often at high altitude), some creative thinking was needed. A cold dry montaine environment and a blanket of winter snow is hard to achieve in the New Forest and as a result many plants have died over the years. After several incarnations we now grow a mixture of sun loving plants from across the world including Grevillea, Leptospermum, Cistus as well as ericaceous plants such as Gaultheria and many others from the southern hemisphere which enjoy the sandy soil and dry aspect such as Callistemon. Lionel commissioned Edward Balls, a famous alpine plant collector to design the Rockery, incidentally it is over 2 acres in size making it the largest man made rock garden in Europe.