Following visits by government inspectors, no evidence of Chalara fraxinea / ash dieback has been found at Christie-Elite Nurseries.
Chalara fraxinea, the fungus which is responsible for causing the tree disease commonly known as ash dieback or Chalara dieback, was first recorded in the early nineties in Poland and has been spreading through Europe steadily since then. It is a new strain of a species which for years had been regarded as a harmless leaf litter decomposer; scientists are yet to explain why or how a harmless endophyte, or an organism which lives in plants without causing apparent harm, turned into a pathogen deadly for ash trees.
The disease causes crown dieback and leaf loss (much more information on recognising the disease and its symptoms can be found at http://www.forestry.gov.uk/chalara). Young saplings can succumb to the disease very quickly, more mature trees can last longer, but often fall victim to secondary infection from honey fungus and similar. The disease has serious consequences to the landscape of Britain if the disease continues to spread at its current rate. An estimated 90% of Denmark's ash trees are infected, and ash makes up around 30% of Great Britain's woodlands. The spread of the disease within GB is thought to be primarily through imports of ash from European nurseries, though the spores are also thought to be capable of being wind-dispersed across the Channel.
As of the 29th October 2012, following the discovery of a few cases of the disease in natural woodland sites in East Anglia, Owen Patterson, the Secretary of State for Environment, Food and Rural Affairs announced a ban on the import and restriction of movement of ash within the UK. As the law currently stands ash can only be moved with a plant passport which will be issued following inspections and which certifies that the ash comes from a disease-free zone. At this time no disease-free zones have been identified which effectively means a freeze on any movements until further notice.
Following this a survey to try and map the extent of the disease was initiated with samples taken from 2500 10km squares. This survey shows that, at the time of writing, there are 129 confirmed sites with ash dieback in the UK.
As a leading UK tree nursery we are extremely concerned about the threat posed by Chalara fraxinea and, as part of the Horticultural Trades Association's Tree and Hedging Group, have been involved in seeking ways to halt the progress of the disease. As part of CONFOR's Nursery Producer Group we have signed up to a voluntary scheme to increase transparency and traceability whereby we will publish the country of production of all our stock to give customers the assurance that their UK provenance stock is also UK grown, two terms that have not always been synonymous.
Our nursery was tested in the summer for a number of known diseases, including Chalara fraxinea, and was found to be free of them. Evidence of this, along with other relevant documents, can be downloaded from this section of the website. At time of writing we are currently awaiting further inspection following the change in the law. There is currently no evidence whatsoever of the disease spreading to any trees outside of the ash genus, and would urge customers to consider alternatives to ash rather than to halt operations altogether. There is a chance that the disease free zones will be put into place soon and the movement of ash can resume, though it's more likely this will take some time. In the meantime the natural resistance to the disease that some trees seem to be exhibiting needs to be studied further, especially if the fungal spores causing the disease are in fact being windblown across the channel. If this is the case then it is unlikely that we can ever eradicate the disease and instead need to look at ways to work around it.
We are committed to production of healthy, disease-resistant trees of the highest quality. To this end we have bio-security measures in place for nursery staff and visitors including foot dip trays and vehicle disinfectant kits. We are also committed to playing our part in ensuring the future health of the UK's planted trees by supporting the industry's move to reduce dependence on a few tree species. We would welcome discussions from any client considering alternative species so we can make sure plants are available. A statement concerning alternative species is available from our website which outlines our position more clearly.
At this time we await the UK government's demarcation of disease-free areas and remain unable to ship ash, within or without the UK. If the situation should change, all the ash available for sale has been grown here at our Scottish nursery and is of a Scottish seed provenance.
For all other species, it's business as usual.