Oaks at Chevithorne Barton

The new growth of Quercus texana 'New Madrid' flushes in shades of red and bronze.

Members of the International Oak Society discussing oaks at Chevithorne Barton

The International Oak Society held a study day today at Chevithorne Barton, near Tiverton, Devon, which is home to the most complete collection of different oaks in Britain. It has been put together over the past 25 years or so by Michael Heathcoat Amory, who kindly asked me to join them, enabling me to catch up both with the trees, which I last saw about five years ago, and a lot of friends from home and abroad. There are over 400 different oaks in the collection, including cultivars, ranging from the small and shrubby, such as Q. monimotricha from the Tibetan borderlands, to the potentially enormous, such as Q. castaneifolia, and from the very familiar to the latest introductions as acorns last autumn. As such, it provides an unrivalled opportunity to study the species and their hybrids - oaks are very promiscuous - and begin to get an understanding of what they look like. Since oak foliage varies between the different flushes in the year, and with the age of the tree this is by no means an easy matter. Winter hardiness was also a  subject for much discussion, with some surprising survivals and some sad losses.

The pachydermatous bark of Quercus affinis, a very hardy Mexican species

The death of the former champion Quercus candicans from the winter cold was greatly lamented.

Quercus intricata from the Chihuahuan Desert in the USA and Mexico seems to be unscathed by the low winter temperatures (-15 was recorded).

Quercus lamellosa is recovering after the winter.

Quercus ithaburensis subsp. macrolepis from the Balkans and Turkey is perfectly hardy.

Michael Amory's book The Oaks of Chevithorne Barton  (2009) is the most comprehensive illustrated guide to the genus Quercus in English, and a new website with the same title has just been launched, providing an extremely useful online guide to the collection and the diversity of oaks.