This year so far has not produced great growing conditions for some species of tree, whilst others have flourished. In particular Korean Hornbeams have not produced the same level of growth as last year. This could be down to the weather conditions throughout this summer but based on the levels of rainfall and moisture I do not expect a great autumnal display either as environmental factors play an important role in the development of autumn colour. Deciduous trees and shrubs loose their leaves during autumn and this involves a series of complex physiological processes and anatomical changes to take place.


Senescence is one of these processes and is a degenerative process but most notably assures the break down of a range of substances within the leaves such as protein and chlorophyll. The second process is that of abscission which is the actual separation process of the leaf from the stem and normally follows senescence. The colour change then is the most obvious sign that senescence is taking place.


During the process of senescence Anthocyanins are broken down in some species of trees and these are responsible for the production of the pigments that account for the red, pink and purple colours. While other tree species turn characteristic colours like yellow and these pigments come from the breakdown of Carotene and Xanthophyll.


Some trees though have a combination of both pigments which them allows for a greater colour range of oranges, crimsons, purples etc. The yellow brown colour change though for Oaks come from the break down of the tannins.


Here are a selection of images showing the great colour changes that you can see with your trees this time of year even if your trees do not put on such a good display this year. There is still time as many trees have yet to turn though….