Oak trees have been banned at Chelsea Flower Show because of fears the oak processionary moth could spread across Britain.
The moth causes significant damage to oak trees and releases tiny hairs as a caterpillar which can cause severe allergic reactions.
It has taken hold in West London, and any oak tree taken to chelsea risks being infected.
This has caused a headache for exhibitors with one insider telling the Telegraph: “we know one designer who had to redo his whole garden because all the trees he was planning to use were on the banned list.”
Guy Barter, chief horticulturalist at the RHS, told the telegraph: “the processionary moth is embedded in London now. It only appears on oak trees and has now spread around West London. If anyone brought oak trees to Chelsea it would have to be destroyed in situ because of a contamination risk. We have plant health inspectors on site to check. “If the disease comes to Chelsea it could easily spread all around the country. “We strongly encourage people to source all their plants from Britain.
Also on the banned list this year is non-native lavender, with anyone showing a garden with the fragrant herb having to source it from England.