Sarah Eberle is designer and commissioner is the Animal and Plant Health Agency (APHA).
‘Beyond Our Borders’ shows ‘plant sentinels’, including UK native plants, which live outside of their natural ranges in botanical gardens around the world. These plants are being monitored for pests and diseases that could potentially attack our native species.
The garden features three climatic zones (Australasia, Arid and Tropical) which are divided by water features that represent oceans. Each zone contains a British tree ‘sentinel’ standing among plants native to each. Coiled springs and pulsing lights represent pests and diseases and their movement both within countries and across borders due to the increased trade in plants and plant material, global travel and natural spread.
Paul Beales, head of Plant Health Public Engagement at the APHA, said: "The issue of the increase in the arrival, establishment and spread of plant pests is a global one, largely due to international trade and travel, and needs to be tackled as such.
The garden represents the need for us to work together and share information and knowledge on an international scale."
In the last few years, a number of new pests and diseases have emerged as significant threats to trees and other plant species in the UK, including Ash dieback (Chalara fraxinea), Ramorum dieback (Phytophthora ramorum), Oak Processionary Moth (Thaumetopoea processionea) and Asian longhorn beetle (Anoplophora glabripennis).
These pests and diseases are often not considered a threat in their native regions because the host plants have evolved resistance to them and/or because natural predators keep numbers down.
However, because UK native trees may not have developed natural resistance to these threats, and there are fewer or no natural predators, they are more likely to be severely affected. Monitoring plant ‘sentinels’ abroad will help to establish which pests and diseases pose the biggest threat to our native species, and this information will be used to inform plans for prevention, eradication and control.
Defra Chief Plant Health Officer, Nicola Spence, said: "It’s great that this year’s garden highlights the important work going on to identify, prevent and tackle pests and diseases that can harm our native plants and trees.
"There are simple steps everyone can help with, such as keeping a look out for signs and reporting sightings of tree pests and diseases, and not bringing back plants from abroad, which will help to protect our countryside and wildlife."
Sponsors of the "Beyond Our Borders" garden include Defra, Botanic Gardens Conservation International, the Scottish Government and the Horticultural Trades Association.
For more information on the garden visit: www.plantsentinel.org/apha_rhschelsea/