Ash dieback - RHS update
20 November 2012
The RHS participated in the Defra Ash dieback summit (Wednesday 7 November 2012), which fed into the Government’s Written Parliamentary Statement and action plan. The RHS welcomes the rapid action taken to combat the spread of the disease and while this is a quickly changing situation, and believes it has a critical role in providing appropriate information to help the nation’s gardeners.
It is clear from initial survey results carried out by Defra, the Forestry Commission and others that the disease is more widespread than previously thought and it appears it has been in the UK for at least two years. While the first detection of the disease was in imported nursery stock it seems that the disease reached the UK naturally with spores blown over from mainland Europe. This has significantly changed the way the disease needs to be handled.
The Government’s action plan identifies clear objectives to help reduce the spread of the disease. The immediate commitment is to destroy infected young plants and to reduce the rate of spread. The action plan states that mature trees will not be removed as they are valuable to wildlife, take longer to die and can help us learn more about genetic strains that might be resistant to the disease.
Ash trees are not common in private gardens due to their size, but are, of course, a valued tree in the landscape and for its environmental qualities as well as its commercial value as a forestry tree.
The RHS and our members are extremely concerned about the disease and its devastating effect on the landscape, forests and ecology. We are advising gardeners of symptoms and urging anyone to report suspected cases to the relevant plant health authority. Our website has up-to-date information relevant to gardeners.
RHS Gardens are not affected at the moment, but we are being extremely vigilant and checking our ash trees regularly. However, as the disease has been found in East Anglia near to Hyde Hall, we have taken the precaution of closing the woodland areas at the garden.
The information now available indicates that the fungus has a limited period during the year when it is infectious, which is from June to October. In addition there is a low probability of the spores being dispersed on clothing and footwear. For this reason the RHS has decided not to install disinfectant mats or other biosecurity measures for visitors. However we do, as a matter of course, have biosecurity in place as part of our standard practices against the transfer of pest and diseases within the garden; these restrict vehicle movements in and out of gardens and involve the application of disinfectant on entry and exit including tools, equipment and boots. We also have protocols in place which relate to the purchase of plants and their entry into the garden.
We are collating information for visitors at all four RHS gardens highlighting symptoms to look out for and providing advice. The RHS has put together a working group including RHS scientists and garden curators to co-ordinate the Society’s response.
The RHS will advise exhibitors at RHS Shows of ban on movement of ash plants, trees or seeds for as long as this remains in place. More generally we are reviewing and updating our advice on conservation and environment issues for exhibitors. At RHS shows we will also be raising awareness of plant disease issues and offering advice.
RHS advice on ash dieback
Pictorial guide to recognising the main symptoms
Forestry Commission information, including videos
New 'ashtag' app for ash dieback
Goverment statement on Ash dieback
Main picture above: Chalara dieback of ash (Chalara fraxinea), Forestry Commission Picture Library