Strict new controls to protect the UK’s trees and plants against damaging threats

21 April 2020

New national measures have come into effect to safeguard the UK, and our forestry and horticulture industries, from a range of plant health diseases and pests including the devastating Xylella fastidiosa and exotic beetles which can kill ash trees.

These new regulations, detailed in the Defra press release below, will add more stringent import requirements to protect UK plant health against these threats.

  • Xylella – The import of Coffea and Polygala myrtifolia species is now prohibited, due to a high disease rate in these species, as well as stronger import requirements for other high-risk hosts (including Olive, Almond, Nerium Oleander, Lavender and Rosemary).
  • Emerald ash borer (beetle) – New measures applying stronger import controls to countries within 100km of confirmed outbreak areas. This includes the removal of an option, within EU legislation, to remove the bark and sapwood to a depth of 2.5 cm for all countries regulated for emerald ash borer. This will help mitigate the risk of importing infected wood which has not properly met the official requirements.
  • Plane tree wilt – More stringent ‘Protected Zone’ requirements for the UK including measures for plane trees, intended for planting other than seeds, which must now have been grown throughout their life in a pest free area or an EU Protected Zone. The new requirements apply to imports to the UK from Albania, Armenia, Switzerland, Turkey, the United States and the EU-27.

UK Chief Plant Health Officer Nicola Spence said: 

“Protecting our country from tree pests and diseases is key to protect our environment, economy and our health. 

“That is why we are introducing tighter restrictions on the importation of high risk host plants and trees for Xylella, emerald ash borer and plane wilt.  

“Xylella is a major threat to our landscape and industry and in this year of International Plant Health it is more imperative than ever that we do all we can to ensure the UK remains a Xylella-free zone. Emerald ash borer and plane wilt also represent significant threats, which is why we are bolstering our protection against them, in response to recent changes in the risk situation.”

The new legislation will also amend an area of the EU Plant Health Regulation concerning the plant disease Elms Yellows and the UK’s Protected Zone. Elm yellows is a plant disease of elm trees that is spread by leafhoppers or by root grafts. 

Professor Saskia Hogenhout, leader of the BRIGIT consortium at the John Innes Centre, said: 

"We welcome these new regulations which will be a key step in keeping the UK free from Xylella. Through the BRIGIT programme we are investigating how Xylella may spread in the UK environment, by assessing how symptoms may develop in plants, the prevalence and movement of insect vectors and how Xylella may move around the country via transport of plants. 

“We also organise public engagement events to distribute information about Xylella and risks associated with importing ornamental plants into the UK. All of these components are vital in developing an effective regulatory framework to manage the threat posed by the disease." 

Further information on the new plant health national measures can be found on the Defra Plant Health Portal, here. 

The new legislation is amending the Official Controls Regulations 2019, to address new plant health threats. 


  • On Tuesday 31 March Defra introduced legislation which implements new measures for Xylella following the recent consultation and Defra’s response, as well as new measures for emerald ash borer, canker stain of plane and elm yellows.
  • The new legislation is summarised here with further details provided in an annex
  • The government recognises the challenges that the horticultural sector and individual businesses are facing at the current time due to the coronavirus pandemic, and has carefully considered the timing of these new regulations and agreed that it is important to proceed now to protect the UK’s biosecurity and given the support of industry and stakeholder representatives through the Plant Health Advisory Forum and Tree Health Policy Group.
  • Further information on plant health imports and exports regulation can be read on the Defra Plant Health Portal.
  • The UK will continue to apply the derogations in place for imports of wood of ash from the US and Canada (EU Implementing Decisions 2018/1203 and 2016/412 refer), which include requirements to mitigate the risk of introducing emerald ash borer.