How biosecurity can prevent the introduction and spread of tree pests and diseases

Find out what you can do to prevent tree pests and diseases from establishing and spreading.

Biosecurity refers to a set of precautions that aim to prevent the introduction and spread of harmful organisms. These include non-native tree pests, such as insects, and disease-causing organisms, called pathogens, such as some bacteria and fungi.

Tree pests and diseases can be transported between or within countries via a number of pathways, including:

  • live plant and tree products, such as potted plants
  • timber and wood packaging materials (WPM), such as shipping crates and pallets – find out more if you’re an importer using WPM
  • dirty tools, kit, machinery and vehicles, such as chainsaws, boots and all-terrain vehicles
  • soil and organic material, such as leaf litter
  • natural methods, such as wind and water

There has been a significant increase in the number of non-native tree pests and diseases being introduced to the United Kingdom since the early 2000s. This demonstrates the need for us all to take action to provide our trees, woods and forests with greater protection. By implementing appropriate biosecurity measures, we can significantly reduce the risk of introducing and spreading tree pests and diseases.

This page will show you how to maximise good tree health through biosecurity.

See Forestry Commission guidance on importing and exporting wood and timber products.

What you can do


Tree pests and diseases can have a significant impact on our landscape, but there are some simple steps members of the public can take to help limit their spread:

  • drive and park your vehicle only on hard-standing surfaces such as tarmac where possible when visiting outdoor areas such as woodlands, parks or gardens
  • before you leave: clean mud, organic material and water off your boots, bikes and buggies, and check over your dog, because fungi, bacteria and insects can get everywhere
  • Don’t risk it!’: please don’t bring any plant or tree products back from trips abroad, because these might be carrying harmful non-native tree pests or pathogens
  • report any trees that you suspect are in ill-health to the Forestry Commission, Scottish Forestry and Natural Resources Wales using TreeAlert

Industry professionals

People working in the arboriculture, forestry and landscaping industries are considered a particularly high-risk group for their potential to spread tree pests and diseases.

The Forestry Commission has worked closely with the following organisations to develop industry-specific biosecurity guidance to reduce their members’ risk of introducing or spreading pests and diseases:

By following the 3 calls to action from our industry guidance, ‘Think kit, think transport, think trees’, alongside the public biosecurity guidance above, industry professionals can significantly reduce the increased risks to tree health associated with these sectors.

Think kit:

  • make sure all equipment, including boots, clothing, ropes and saws, is free from soil and organic material before entering and leaving a site
  • regularly clean ropes as per the manufacturer’s guidance, or use dedicated ropes for particular sites
  • clean and disinfect chainsaws, pruning saws and other cutting tools as part of routine maintenance, and before using them on a new site

Think transport:

  • remove any build-up of soil and organic material on vehicles and machinery, including cabs, wheels and foot wells, before leaving each site
  • use proper off-site wash-down facilities regularly

Think trees, plants, and materials:

  • responsibly source planting stock through nurseries or suppliers that adhere to national standards such as the Plant Health Management Standard, or that have their own biosecurity policy in place that you trust
  • source planting stock from pest and disease-free areas
  • keep accurate, up-to-date records of all purchases and supplies to assist with tracing exercises in the event of an outbreak
  • regularly monitor plant and tree stock for signs of ill-health, and report any suspect symptoms using TreeAlert
  • if you’re responsible for importing or moving plants, check your plant passport and registration requirements with APHA before doing so
  • source landscaping materials from pest-and-disease-free areas only
  • be aware of any restrictions in place, or phytosanitary (plant health) measures and treatments required when importing certain materials or their packaging
  • specify British-grown plants when sourcing planting stock, to reduce the risk of an accidental introduction of invasive non-native pests or diseases

When working on a site that is subject to a Statutory Plant Health Notice, or where a pest or disease has been confirmed, you must follow any additional biosecurity guidance for that pest or disease in addition to the measures here.

If you must remove infected or infested material from such sites for safety reasons, you must ensure that:

Land owners and managers

As a land owner or manager, it’s particularly important that you implement appropriate biosecurity measures to prevent the introduction and spread of tree pests and diseases. Not only can these organisms affect the economic value of your trees, they can also have a wider negative impact on other species and habitats.

By following the biosecurity guidance provided above for the public and industry professionals, you can significantly reduce the risk of tree pests and diseases spreading on to your land. If, however, a tree pest or disease is confirmed on the land you own or manage, there are some additional measures you need to follow:

Statutory Plant Health Notices (SPHNs)

If the tree pest or disease found on the land you own or manage is classified as notifiable, you may be issued with an SPHN. The Forestry Commission and other plant health authorities issue these notices requiring the owner or manager to take certain steps to eradicate or contain notifiable pests and diseases.

SPHNs requiring eradication may require measures to kill the infected or infested trees, such as by felling or ring barking. SPHNs ordering containment measures may allow the infected or infested trees to remain standing, but require any susceptible material to remain on site.

If you’re issued with an SPHN, you must follow any instructions provided within the document. If you have any questions about an SPHN you have been issued, contact the Forestry Commission.

Note that receipt of an SPHN doesn’t mean that you’re in any trouble. Nor does it imply that you have committed an offence, or are at fault for the pest or disease being present on your land. However, failure to comply with the requirements of an SPHN can result in enforcement action and prosecution.

Non-notifiable pests and diseases

You’re not required to take any action if the tree pest or disease found on your land is not notifiable. We do, however, recommend that you take the following measures to ensure people’s and animals’ safety, and to minimise any further spread of the pest or disease. You should:

  • continue to implement the biosecurity measures in the public and industry professionals sections above
  • make any visitors aware of the presence of pests and diseases on your land through information boards, posters at entry points, and/or by adding information and biosecurity guidance to your site’s website, if available
  • monitor the trees’ safety as the infection or infestation progresses, and prune or fell affected trees if they threaten to cause damage or injury
  • in low-density situations, such as in parks or gardens, slow the spread of pests and diseases by removing and disposing of (by burying, composting or, where permitted, burning) infected trees and their fallen leaves and branches

Biosecurity kit

Putting together a simple, portable biosecurity kit can help you implement simple measures every day to help limit the introduction and spread of tree pests and diseases. The following are cheap and easily obtained items to include in your kit:

  • bucket (big enough to fit your boot and a few inches of water)
  • boot pick
  • brush
  • disinfectant
  • hand sanitiser
  • water container (or a large re-used water bottle)
  • portable pressure washer (optional, but handy for cleaning bikes or other equipment that won’t fit in a bucket)


The number of introductions of tree pests and diseases has increased. It is therefore more important than ever that we all learn how we can help to minimise the risk of further introductions and spread through the effective application of biosecurity measures.

Our biosecurity e-learning package was developed with the Animal and Plant Health Agency, the Arboricultural Association and the British Association for Landscape Industries. It provides background information about biosecurity issues, and clear guidance on the most effective and appropriate biosecurity measures for different situations.

The package can be accessed via the Forestry Commission’s e-learning portal. Before you first use it, you’ll be asked to register and create an account. Once your account is verified you can enrol for the online courses.

The package is divided into 5 modules:

  • Module 1: Biosecurity awareness
  • Module 2: Biosecurity – dispersal pathways
  • Module 3: Biosecurity measures
  • Module 4: Biosecurity – personal controls
  • Module 5: Biosecurity – import and export requirements for wood packaging material

At the end of each module is a short test to establish your understanding of the subject. The pass mark for each test is 80%, and there is an option to re-take the test if required.

If you have any queries about the e-learning package, contact the Forestry Commission.


‘Keep it Clean’

The Forestry Commission’s ‘Keep it Clean’ campaign is a simple, memorable call to action to everyone to incorporate biosecurity measures into their daily routine. You can support the campaign by downloading the media and tools and using them within your organisation any way you can.

You can also show your support on ‘X’, formally Twitter, by using the Forestry Commission’s ‘Keep it Clean’ Twibbon

Other useful resources


Contact the Plant Health Forestry team for queries about tree health surveillance, biosecurity, forestry reproductive materials and the import, export and movement of timber and wood products.

For e-learning enquiries please send an email enquiry to:

Use TreeAlert to report a suspected tree pest or disease to Forest Research, Forestry Commission, Scottish Forestry and Natural Resources Wales. Find out more about identifying and reporting suspected tree pest and disease issues.

Sign up to Tree Health News for the latest information on tree and woodland health.

Sign up to Plant Health News to receive up-to-date forestry trade news.

Follow @ForestryComm on Twitter for updates on forestry grants, regulations and tree health in England.

Published 26 September 2018
Last updated 23 August 2023 + show all updates
  1. Information on biosecurity kits disinfectants has been removed.

  2. Remove the following documents: • Industry leaflet (arboriculture) (PDF, 1.16MB, 2 pages) • Industry leaflet (forestry) (PDF, 979KB, 2 pages) • Industry leaflet (landscaping) (PDF, 992KB, 2 pages) • ‘Think kit, think transport, think trees’ poster (PDF, 43.8KB, 1 page) Added the following documents: • Biosecurity leaflet for professionals’ • ‘Think kit, think transport, think trees’ poster – professional audience • ‘Think kit, think transport, think trees’ poster – public audience

  3. Updated contact information.

  4. This page has been updated with the latest ‘Keep it Clean’ resources.

  5. Added a URL and did some tweaking.

  6. First published.