Sudden Oak Death – Phytophthora ramorum

Practical advice for Scotland's gardeners has been made available from the National Trust for Scotland charity, in the light of recent outbreaks of a disease that can affect the likes of rhododendron and viburnum.

A set of user-friendly tips for consumers has been issued, with detailed guidance on how to deal with Phytophthora ramorum, also known as Sudden Oak Death, for gardens, plant sales and established gardens.

Phytophthora ramorum (Sudden Oak Death) was first discovered in the United States. By February 2006 the disease was recorded it 546 sites in England and Wales.

The disease has so far been found in just four Scottish Gardens, including two examples at the National Trust for Scotland’s Arduaine Garden and Inverewe Garden but affects many places in England and Wales. A similar disease, called Phytophthora kernoviae, has also been detected in one non-Trust garden.

The charity has played a leading role in addressing the problem of Phytophthora ramorum, ever since it was detected at Arduaine last October. The Trust has been working closely with SGRPID, the Scottish Government Rural Payments and Inspections Directorate, on how best to manage the disease.

Recently, in partnership with the Royal Botanic Garden Edinburgh, the Trust brought together its own gardening specialists from popular properties throughout Scotland, government authorities, the (English) National Trust and some private gardens, to share detailed practical knowledge.

Jan Haenraets, Head of Gardens and Designed Landscapes Services said: “We felt it important to bring some of the specialists together to raise awareness and share our first hand knowledge and best practice, looking at the problem from both a gardens and countryside perspective. In a collaborative effort with SGRPID and Scottish Natural Heritage, we hope we can improve how we deal with the problem in Scotland for all organisations.

“But we also wanted to offer the public some useful advice, for the many keen gardeners at home and enthusiasts who visit our gardens. The disease is still not widely understood so it’s important to get things into perspective and look at the problem in a very practical way. We hope our key tips help Scotland’s home gardeners better understand the plant disease.”

Ann Steele, Gardens and Designed Landscapes Adviser for the Trust added: “This disease is still very rare in Scotland but it’s been a problem in England, so gardeners should watch out if woody plants seem to die quickly, keep gardens and tools clean, buy your plants from a trusted source and if you’re concerned, contact your local SGRPID office. There are images of diseased plants available online at the SGRPID and DEFRA websites, so that’s a useful reference for concerned gardeners too. Gardens that have been affected by the disease must display a notice that advises visitors of this fact but don’t be put off visiting a garden where an outbreak has occurred. Just make sure you stay on the paths, follow the signs and please don’t take any leaves or cuttings away with you when you leave.”

The National Trust for Scotland’s advice is given below:

1. Keep up to date with current notifications and images via the DEFRA or SGRPID websites: http://www.defra.gov.uk/planth/pramorum.htm

2. If woody plants seem to die quickly, check to see if they are amongst susceptible genera, e.g. Viburnum, Rhododendron, Erica, and Pieris etc.

3. In areas where outbreaks have occurred, ensure gardens are kept clean – remove leaf debris and burn.

4. Keep tools clean and disinfected to prevent disease spread.

5. Remove soil from shoes and boots with soap and water.

6. Buy your plants from a trusted resource and ensure they adhere to the plant passport scheme, ensuring the plants have been grown in safe, clean and hygienic conditions.

7. Contact your local SGRPID office if you have any concerns with plants, but try to check with guides first.

8. If visiting areas where outbreaks have occurred, make sure you take no leaves of illicit cuttings from the garden and keep dogs under control on short leads.

9. The best advice is to be aware, keep an eye on your plants and follow the normal good husbandry that all gardeners work to.