At a time when volunteering in parks is rapidly rising, Derek McCann of the Animal & Plant Health Agency said parks should be careful about volunteers who could easily bring in unwanted matter on their footwear. Boots, shoes and tools should be cleaned and hands and vehicle wheels disinfected for all those coming on site, he advised.
Increasing globalisation is also a problem, he said, with "love of the new" creating "demand for instant landscapes" and exotic plants. "Tree ferns are coming direct from Australia. The world is shrinking. We're suffering from an unprecedented attack," said McCann.
Parks managers should use approved suppliers and be specific with orders. He described how one customer fell foul of tree disease after buying British stock that had been grown in Europe, thus exposing it to disease.
"Wherever possible, seek to purchase plants that have been propagated and produced within the country. This reduces the chances of introducing pests or disease.
"If there is a specific need for plants from a doubtful supplier, they should go through quarantine on arrival in a separate area of the garden - hold for six weeks if possible.
"When plants arrive they, and their documents, should be checked carefully." But McCann added: "Don't panic - an outbreak is not the end of the world."