Looking Up, Looking Down: Why Biosecurity Matters for Tree Health

When it comes to tree health, most of us spend a lot of time looking up. We look for thinning canopies, dieback, unusual leaves, bleeding cankers and changes in bark. Observatree volunteers, foresters, land managers and woodland owners all know the importance of spotting the signs when something isn't right. But protecting trees isn't just about what we see in the branches above us. Sometimes, it's about what we're carrying beneath our feet.

Tree pests and diseases spread in many ways. While some move naturally through wind or water, others are carried unintentionally on the things we use every day. Mud caught in the tread of a walking shoe. Soil clinging to a spade. Leaf litter lodged in a bike tyre. Small traces of the places we've visited can travel much further than we realise.

These are easy things to overlook, but they can provide a pathway for harmful pests and diseases to reach new locations. From Phytophthora species in contaminated soil to fungal spores carried on equipment, some threats can travel unnoticed from one site to another. That's why biosecurity matters.

Why Biosecurity Matters

Biosecurity is a set of practical measures that help prevent the introduction and spread of harmful pests and diseases.

For those of us who spend time outdoors, biosecurity starts before we even leave home. Whether you're surveying trees, carrying out practical conservation work or simply heading out for a walk, taking a moment to think about where you're going, what equipment you're taking and how you'll avoid moving soil and organic material between locations can make a real difference.

Simple actions such as cleaning mud and debris from footwear, bike tyres, tools, and equipment before heading somewhere new can help reduce the risk of spreading pests and diseases. If you're walking with a dog, it's worth checking their paws and fur too, as they can pick up and transport mud and organic material between locations. Where possible, it also helps to drive and park on hard-standing surfaces, such as tarmac, when visiting woodlands, parks or gardens, rather than on verges or unpaved ground.

Individually these actions may seem minor, but together they help reduce opportunities for pests and diseases to hitchhike into new areas. The challenge is that many people don't realise how easily these organisms can be moved, or the difference a few preventative actions can make. Helping people understand that risk has been the focus of the Forestry Commission's Keep It Clean campaign for the past decade.

Ten Years of Keep It Clean

To mark its tenth anniversary, Keep It Clean is launching a refreshed collection of campaign materials, rolling out from 29 September, including four short films that show how biosecurity fits into everyday outdoor activities.

For ten years, the campaign has encouraged people to recognise the role they can play in protecting trees, woods and forests. The message is clear: small actions, carried out consistently, can help reduce the spread of harmful pests and diseases.

The films explore different aspects of biosecurity, from the hidden ways pests and diseases can travel to the practical actions that help stop their spread. The first film, The Trails We Leave Behind, is available to watch now.

Alongside the films, new posters and social media graphics will help share these messages with an even wider audience, helping more people understand the role they can play in protecting tree health.

Before you move on

Whether you're surveying trees, carrying out woodland management, volunteering on a conservation project or simply enjoying a walk, you can help protect the places you visit. Before you head somewhere new, take a moment to stop and look down. What you leave behind matters. What you carry with you matters too. Check and clean your footwear, bike tyres, tools, and equipment, removing any visible mud and organic material. It only takes a few moments, but those moments matter. Because protecting tree health isn't just about looking up and spotting the signs of a problem. Sometimes, it's about looking down and helping prevent the next one.

For further information on how to prevent the introduction and spread of tree pests and diseases visit: How biosecurity can prevent the introduction and spread of tree pests and diseases - GOV.UK