A rise in new diseases

Pest and diseases in the UK are starting to become more widespread, says the RHS. Annual rankings of problems encountered by RHS members indicate diseases, such as kerria twig and leaf blight, are rising. That disease is now number 10 in the rankings, after being first identified in 2014.

Blight and volutella disease of box is also becoming more prevalent, with the latter making fifth and sixth place in the charity’s top 10 disease problems.

In the pest category, box tree caterpillar and fuchsia gall mite have both risen in importance, with the former becoming the number one pest and the latter number two, knocking slugs and snails and vine weevil off the top slots.

Honey fungus remains the gardeners number one nemesis, having retained its position 22 years running.

“With new pests and diseases emerging in continental Europe, it has never been more important that people get to grips with what’s going on in their gardens,” said RHS plant health head, Gerard Clover.