Recommended Sources

The purpose of this page is to signpost  information from across plant health sectors that is relevant to the natural environment.


About This Page

Much information is available online and in print to help identify disease symptoms, the organisms that cause them, and to provide guidance on management and biosecurity. Here we have collected sources we judge to be generally reliable for information on these topics. You can use the Resource Type button to filter, search by keyword, or scroll through all together. It should be noted that most information on these webpages concerns invasive non-native species (INNS) or those which have recently become problematic, possibly due to climate change. However, there are many native pathogens that have evolved with their hosts and are commonly encountered in the natural environment. See Getting Started for good places to begin in identifying both native and INN pests.

Getting Started

Good places to start in the identification process include the CABI Field Guide for the Identification of Damage on Woody Sentinel Plants, CABI Plantwise Diagnostic Field Guide (for crops but very useful) and also Diseases and Disorders of Forest Trees. Furthermore there are several websites with information on common disease causing organisms in the natural environment including the tree decay fungi webpage of GMC Arboriculture and First Nature. If you need help identifying insects you could contact the Royal Entomological Society, the RHS, or SASA. The Arboricultural Association also have a book shop where excellent guides can be purchased on 'Fungi on Trees', 'Tree Pest and Diseases' 'Managing Insects and Mites on Woody Plants' and 'Diagnosis of Ill Health in Trees'. Detailed information on most disease causing organisms can also be found on the Plantwise Knowledge Bank Database (Plantwise fact sheets). For general information on tree diseases, the Forest Pathology website is very useful. Whether the organisms are INNS or native pests and diseases, be sure to practice good biosecurity and take control measures where necessary.

Reporting Notifiable Pests

Most pests encountered will not be notifiable but if after checking diagnostic and specific resources you think you may have encountered a notifiable pest it is important that you report it quickly. In forest trees in Scotland notify Scottish Forestry via TreeAlert or by email, or if in any other plants notify the Horticulture and Marketing Unit at SASA. Outwith Scotland, consult the Plant Health Information Portal for other UK reporting contacts.

Resource Details

An initiative to protect oak trees


Animal and Plant Health Agency - Plant health controls and reporting pests and diseases, information on certification schemes

APS advice page

American Phytopathological Society - Links to very comprehensive web pages for diseases caused by plant pathogens


Arborist website with tree health forum


British Association of Landscape Industries - Pest and Diseases section with Landscape Institute Toolkit for biosecurity guidance


British Crop Protection Council - UK Pesticides Guide Online, subscription guides to the pesticides and biocontrol agents registered for use in the UK


British Society for Plant Pathology - new disease reports and publication of scientific journals


CABI provies comprehensive cross sector information including plant health via the Plantwise portal

CABI - diagnostics

Fungal and bacterial identification services at CABI

CABI online book

Field Guide for the Identification of Damage on Woody Sentinel Plants. This guide is recommended as the first step in disease identification of trees and shrubs

Caledon computer game

Manage a simulated forest in the face of disease epidemics and other threats. Computer game for ages 8+

California Oak Mortality Task Force

Extensive biosecurity and best practice guidelines for nurseries and wildland conservation projects issued by the California Oak Mortality Task Force, but relevant to most host plants and locations


Confederation of Forest Industries - Website with plant health webpages 


Plant and Tree Health information from Department of Agriculture, Environment and Rural Affairs in Northern Ireland. 

DEFRA - pest and disease factsheets

Fact sheets on notifiable and non-notifiable pests and diseases

DEFRA - Plant passporting

Information on plant passport content and format

DEFRA - reporting a pest or disease

Contact information for reporting notifiable diseases to authorities

DEFRA - smarter rules for safer food

SRSF - a package of EU regulations to protect against plant and animal pests and pathogens

EPPO communication kits

Downloadable posters from the EPPO Don't Risk It biosecurity campaign for plant movement with travel

Farm Forestry New Zealand online publication

A Guide to Conducting Forest Health Assessments and Sampling

FERA - diagnostics

Providing cross sector diagnostic services including for viruses

FERA online publication

Nurseries, Retailers and Landscapers - Biosecurity Best Practice Protocols

FERA online publication

Parks and Gardens - Biosecurity Best Practice Protocols

FERA poster

Turning over a clean leaf - guidance in the forms of posters for biosecurity in woodlands and forests, parks and gardens, nurseries and gardens centres, and the countryside

Forest Pathology

Website with excellent information on disease types and other relevant topics. Very infomative and useful for general forest disease information

Forest Research

Forest Research has a search facility which can be used to find publications and research about specific tree health issues and also an updated plant health news webpage

Forest Research

Tree pest and disease posters

Forest Research

Pest and disease resources on specific tree and woodland problems 

Forest Research - diagnostics

The Tree Health Diagnostic and Advisory Service provides advice and where possible diagnosis and identification of tree pests and pathogens.

Forest Research biocontrol agent

Pest management of Great spruce bark beetle (Dendroctonus micans) using a biological control agent 

Forest Research biocontrol agent

PG Suspension is a biological control agent for Heterobasidion annosum (formerly known as Fomes annosus), licensed for use on Pinus in the UK

Forest Research fact page

Links to websites providing resources and guidance on managing resilient forests from Forest Research and the Forestry Commission

Forest Research guidance

Urban Tree Manual  - with some information on plant health

Forest Research newsletter

Subscribe to the Forest Research newsletter 

Forest Research online book

Forest Research Practice Guide on Reducing Pesticide use in Forestry, which contains general good practice advice on tree pest and disease management

Forest Research TreeAlert

TreeAlert is a facility to report notifiable pests and diseases, and to gather submitted information about the tree and forest health which supports monitoring and surveillance work

Forestry Commission book

Diseases and Disorders of Forest Trees (by S.C. Gregory and D.B. Redfern, 1998, Forestry Commission Field Book 16 )

Forestry Commission e-learning

Login as a guest and complete the Forestry Commission e-learning modules

Forestry Commission fact sheet

Forestry Commission biosecurity guidance fact sheet

Forestry Commission newsletter

Sign up for the Forestry Commission Tree Health News updates

Forestry Commission poster

Biosecurity poster from the Forestry Commission on forestry industry standard practices

Forestry Journal

Forestry Journal/Essential Arb - webpages with some articles on tree pests and diseases

Horticulture Week

Magazine and website with plant health plant health webpages and biosecurity information - by subscription


Institute of Chartered Foresters - webpages with some information on tree pests and diseases

International Plant Sentinel Network

Sentinel plants in botanic gardens and arboreta play a vital role in providing information on future and/or known threats

ISPI advice page

International Society for Pest Information - Pest Information Wiki listing many plant pests and pathogens

James Hutton Institute - Ecological Impacts of Tree Diseases

Resource page on managing ecological impacts of Oak Decline, including management case studies and tools to aid conservation of oak associated biodiversity

James Hutton Institute - Ecological Impacts of Tree Diseases

Fact page on the ecological impacts of Ash Dieback, including tools to aid conservation of ash associated biodiversity

Landscape Institute

Website has plant health and biosecurity webpages and a comprehensive Biosecurity Toolkit for practitioners

London Tree Officers Association

Provides advice on threats to tree health with comprehensive information on diagnosis and managment in a matrix

NNSS biosecurity advice fact page

GB Non-native Species Secretariat fact page with biosecurity advice and access to an e-learning biosecurity module


Observatree provides a list of pests and diseases that are being monitored and provides detailed information on them


Observatree is a citizen science initiative providing an early warning system for tree health by carrying out monitoring and surveillance on specific tree diseases 

Observatree biosecurity advice

Observatree fact page with links to general biosecurity

Observatree Blog

Observatree Blog with regular updates and information on monitored diseases

Observatree measures and guidance

Observatree fact page with links to posters and advice

Observatree newsletter

Sign up for the Observatree newsletter for regular updates on monitored diseases

Online book

An Illustrated Guide to the State of the Health of Trees By Eric Boa (CABI), published by the FAO

Pest Risk Register

A searchable or downloadable database which records and rates risks from plant pests and pathogens

Plant Health Centre newsletter

The Plant Health Centre produces regular downloadable newsletters

Plant Healthy Self Assessment

Plant Healthy Self Assessment to help protect businesses and customers against the potential losses and disruption caused by plant pests and diseases, with a full plant health assurance scheme in development

Plant passporting - EU

New EU plant health rules with information on plant passporting

Plant passporting - SASA

Guidance on plant passporting from SASA

Plantwise (CABI)

Comprehensive resource with searchable knowledge bank and diagnostic tool

Plantwise (CABI)

Plantwise Knowledge Bank Pest Alerts are emails containing recent literature reports for a specified area

Plantwise (CABI) - diagnostics

A service for plant disease diagnosis

Plantwise (CABI) online book

Plantwise Diagnostic Field Guide a good guide for learning how to carry out disease diagnosis caused by pests and pathogens

RHS - diagnostics

RHS members can send in diseased samples of plant materials for diagnosis

RHS advice page

Provides advice on biosecurity and on plant diseases

RHS advice search

Search pages with profiles and advice on plant diseases and disorders

Royal Forestry Society

Royal Forestry Society Pest and Diseases webpage provides links mainly to UK Government and Forestry Commission information

Royal Forestry Society fact sheet

Managing Ash Dieback - Case Studies 2019


A division of the Scottish Government largely dealing with pests and diseases, and crop protection, and providing diagnostic services

SASA - diagnostics

Scottish Government provider of diagnostic services in Scotland including viruses and pests

Scottish Forestry

Information on tree health in forestry in Scotland from the Scottish Forestry

Scottish Forestry fact page

Fact page on Dothistroma Needle Blight in Scotland, including information, impacts, and management guidelines

Scottish Forestry fact page

Fact page on Ash Dieback in Scotland, including information, impacts, and management guidelines

Scottish Forestry fact page

Keep It Clean biosecurity advice tailored to the public

Scottish Forestry fact page

Scottish Forestry advice on Phytophthora ramorum in Scotland with biosecurity and replanting information

Scottish Forestry guidance

Policy guidance on planting in Caledonian pine woods to reduce the risk of Dothistroma needle blight

Scottish Forestry guidance for Juniper

Scottish Forestry - Juniper Management Guidelines and planting guidance for Scotland

Scottish Goverment guidance

Scottish Government website for plant health issues

Scottish Government guidance

Scottish Government 'Plants get ill too' leaflet

Scottish Government guidance

Scottish Government plant pests and diseases web pages provides cross sector advice on certain plant health threats

Scottish Government guidance

Guidance on the use of pesticides to reduce impact on the environment and comply with legislation

Scottish Government guidance

Statutory management requirements, providing guidance on the use of plant protection products

Scottish Government online publication

The Scottish Plant Health Strategy

SEARS fact sheet

Scotland’s Environmental and Rural Services fact sheet on biosecurity guidance


Tree and Design Action Group - green infrastructure tree species selection guide with limited pest and disease information

The Arboricultural Association

Tree disease identification and a comprehensive Biosecurity advice document for arboriculture and environmental sectors

Tree Care Forum

Arborist website with search facility for discussions including on tree health

UK Government biosecurity advice

Biosecurity advice for trees from the UK Government and links to useful rescources, including the 'Keep it Clean' campaign

UK Government guidance

UK Government 'Find a specific Pest of Disease'  provides information on organisms either present in Great Britain or posing the greatest threat of entering, and lists by host or threat

UK Government guidance

UK Government updated website on topical issues relating to plant health

UK Government HSE Chemical Regulations Directorate

Comprehensive information on the use and regulation of pesticides and the pesticides register of UK authorised products

UK Government online publication

Outline of the measures that DEFRA and the devolved administrations are implementing to improve plant biosecurity

UK Government online publication

Tree Health Resilience Strategy

UK Government online publication

UK Tree Health Management Plan and research synopsis

UK Government Report a Tree Pest or Disease

Find out when and how to report a notifiable tree pest or disease in the UK

UK Government Tree Pests and Diseases

A comprehensive UK Government website with information on how to identify, report, prevent and minimise the introduction, spread and impacts of tree pests and diseases in the UK

UK Plant Health Portal

The UK Government (DEFRA) Plant Health Portal is an online hub for plant health information, data and resources. It links to the Pest Risk Register which records and rates risks from plant pests and pathogens

USDA Forest Service online publication

USDA Forest Service IPED Field Guide - Pest Evaluation and Detection

Woodland Trust

Provides useful tree pest and disease webpages for native and non-native trees