Monday, June 03, 2013

Rhododendrons, the beautiful invaders

click photo to enlarge
The rhododendron (Rhododendron ponticum) was introduced to the British Isles some time around the year 1763. It was valued as an attractive, evergreen shrub that in May and June produced multiple, large and showy flowers. Its popularity grew and in the nineteenth century it became a staple of large gardens, parks and hunting estates (where it provided shelter for game species) on the wetter, western side of Britain where the soils were acidic. As well as this particular species being widely planted it was also used as a rootstock for hardy, cultivated varieties. With this high level of interest the rhododendron quickly became established and started to spread. By the twentieth century it became recognised for what it was; a rapidly invasive coloniser, filling woodland floors beneath the tree canopy, spreading into moorland and heathland, a plant that suppressed and replaced native species and made forestry much more difficult and expensive. Today the Forestry Commission has programmes of control designed to subdue the rhododendron and remove it from areas where it is not wanted.

One can understand the enthusiasm with which Victorian gardeners adopted the plant. It is like no other evergreen shrub when it is in flower. Not only are the individual blooms very big, they are numerous and quite beautiful. When seen en masse on a large group of bushes the sight is quite overpowering. As a child I enjoyed seeing the purple flowers on the millstone grit rock outcrops and in the woods near Settle in the Yorkshire Dales. In later life I sought out the varieties that Victorian landowners had planted around Bleasdale and Abbeystead in Lancashire's Forest of Bowland: various shades of purple, red, yellow, orange and white could be found. Today I make a point of visiting Woodhall Spa to see the annual show of multicoloured exuberance. Were I a forester, of course, any pleasure I got from the beauty of the flowers would be seriously tempered by the cost and work involved in controlling their spread.

Today's main photograph was taken in the Yorkshire Dales. The shot shows something of the glow that each flower exhibits when seen against the dark green, shiny leaves. The smaller photograph was taken the other day in the grounds of the Petwood Hotel in Woodhall Spa. These rhododendrons, a pink cultivar probably closely related to the ponticum variety, were planted in the early 1900s - about a century ago - and today, in places, form veritable "cliffs" of blooms 25 to 30 feet high.

photograph and text © Tony Boughen

Photo 1
Camera: Canon
Mode: Aperture Priority
Focal Length: 250mm
F No: f5.6
Shutter Speed: 1/200
ISO: 100
Exposure Compensation:  -0.33 EV
Image Stabilisation: On