September 2010
A log book kept by the first curator of Westonbirt, The National Arboretum, shows the prediction of autumn’s timing and colouring has challenged experts for over 80 years.
Predicting the intensity of autumn colour has long been a pastime of tree and shrub specialists at Westonbirt Arboretum, managed by the Forestry Commission since 1956.
This year, experts at the arboretum in Gloucestershire have been comparing 2010 weather and planting conditions with records kept by W. J. Mitchell, the arboretum’s first curator. The records chart autumn colour trends at the arboretum over 80 years ago and were recently transcribed by a volunteer to help with planting research.
W. J. Mitchell took the role of curator in 1927. In the logs, he ponders the traditional conditions thought to be required for good autumn colour. Following a wet and sunless summer in 1936, Mitchell feared a very poor autumn, but was pleasantly surprised, stating:
“There has never been a better all round colour than this autumn; this is making a very bold statement. After this summer and autumn I shall modify my opinion.”
Simon Toomer, Arboretum Director, says that predicting when autumn will fall and what type of colour the leaves of the trees will turn is always a somewhat entertaining task at Westonbirt Arboretum:
“Trying to guess the timing and colouring of trees in autumn is something that we at Westonbirt Arboretum indulge in every year. It's good fun but if I've learnt anything over the years, it's that nature is a mysterious thing and even with increased scientific and plant knowledge, we often get it wrong.”
The closest match to the conditions of 2010 from Mitchell’s log book, which covers 1928 to 1939, is the year of 1929; described as “a year of extremes”, but one which produced autumn colour lasting well into November.
The records show Westonbirt experienced a long, cold spell over the winter of 1928-29, but despite this, many trees survived. The Japanese maples in particular escaped major frost damage, and in the autumn of 1929, were noted by Mitchell for their “exceptionally beautiful” salmon pink leaves.
As in 2010, the winter of 1929 was followed by a later spring than usual, but this was considered by Mitchell to be “one of the most floriferous for trees and shrubs for some years.” Mitchell noted the cherry trees of 1929 to be particularly successful; found also to be the case this year at Westonbirt.
Find out more about what you could see and do this autumn at Westonbirt by visiting our autumn page, or follow the autumn colour watch at www.fowa.org.uk from 1 October.
