Ash Dieback in Garden Trees
Ash disease in garden trees
Ash dieback has hit the headlines recently as the government attempts to stop this disease from devastating ash trees in Britain. So far most of the talk has been about woodlands but what should you do if you have an ash tree in your garden? What symptoms should you watch out for and what should you do if you suspect a tree in your garden to be infected?
The disease is caused by the fungus Chalara fraxinea which is spread by wind borne spores. The first symptoms you may see are spots on the leaves or you may notice that the tree is losing its leaves before autumn arrives. Initially small twigs will die as the disease spreads in from the leaves. Later, as the disease enters larger branches, a canker (discoloured, roughened bark) will spread upwards and downwards from where the infected twig joins the branch. This is often a rough diamond shape. As the fungus kills the tissue more limbs will die back until eventually the whole crown is dead.
The disease has killed 90 per cent of ash trees in Denmark and is prevalent throughout Europe now. Most of the cases recorded in Britain to date are related to imported nursery stock. As so many plants bought at garden centres and nurseries are now imported from Europe, it is quite possible that your garden ash tree may be infected if it has been planted fairly recently. Unless your garden is a large country garden with ash trees grown around as part of wind break, it is likely that you won’t have common ash (Fraxinus excelsior ) planted in your garden. Claret ash or Fraxinus angustifolia ‘Raywood’ is a relative of common ash. With its smaller stature, more delicate leaves and beautiful claret colour in autumn, it makes a good specimen tree. Although Claret ash has been known to host the disease, none have yet exhibited the classic dieback. However this cannot be ruled out in the future and you should still keep an eye on this tree. Mountain ash or Sorbus aucuparia is actually a different species and does not suffer from this disease.
If you do see any of these symptoms in your garden tree it is very important that you contact the Forestry Commission Plant Health Centre on 01420 23000. You should not try to deal with it yourself as it is vital that the Forestry Commission knows of all new cases. Also there are other diseases which cause similar symptoms. There is also an app for smartphone users which allows them to report sightings as well as upload photos of suspected cases. Forget about hashtags, get ashtag, which can be downloaded from http://www.ashtag.org. This application could save the lives of many trees.