The garden is called Beyond Our Borders and has been commissioned by the Animal and Plant Health Agency (APHA). It shows one way that the UK government is working with overseas botanic gardens to protect our environment against alien pest and diseases.

Iconic British tree species are being used as ‘early warning’ sentinels (soldier or guard) in regions throughout the world to monitor and identify potential new plant pest and diseases that could threaten our natural environment.

In the Fresh Garden section, the eye-catching and innovative display features three different climatic zones (Australasia, Tropical and Arid) divided by water features representing oceans.

Each zone contains a single iconic UK native tree sentinel standing among plants native to each climate.

Set within the plants of each zone are coloured springs representing plant pest and diseases. These appear to emerge and disappear and some are stretched to create a wave motion over the top of each ocean. This represents the movement of plant pests and diseases within and between each zone, reflecting the threat to plant health.

Background

In the last few years, a number of new pests and diseases have emerged as significant risks to trees and plants in the UK including:

• Chalara fraxinea (Ash dieback)
• Phytophthora spp.
• Oak Processionary Moth
• Asian longhorn beetle

Pests and diseases like these may not be significant in their native countries because:

• host plants may be more resistant, having grown up alongside them over thousands of years
• natural predators may be present
• environmental conditions can be different

However, plants and trees in the UK may have little or no natural resistance, natural controls may not be present and the surrounding environment is different.

Government action

Safeguarding plants and trees from pests and diseases is one of Defra’s four top priorities. Decisive action is being taken to help protect against the introduction and spread of plant pests and diseases.

APHA is working with Botanic Gardens Conservation International (BGCI), as part of the International Plant Sentinel Network project. The network monitors tree sentinels in international botanic gardens and arboreta for damage by pests and diseases native to that country. It will help to:

• identify potential threats to native UK plants and trees before they are introduced
• improve the chances of eradication or control programmes
• stop their introduction in the first place

How you can help

Sentinel

A sentinel is:

1. a soldier or guard whose job is to stand and keep watch
2. an indicator of the presence of disease

Everyone can help conserve the UK environment be keeping an eye out for any serious pests and diseases that could threaten our plants and trees. You can do this by taking part in the OPAL (Open Air Laboratories network) Tree Health Survey.

To help prevent the spread of plant pests and disease within and Beyond Our Borders you should:

• buy UK-produced seeds and plants where possible
• avoid bringing seeds, plants or cuttings home from trips abroad
• preferably plant small and enjoy watching your garden grow
• become familiar with new pest and disease threats, their hosts and symptoms