Skip to main content Skip to navigation

Royal Horticultural Society's top ten garden pests and diseases - expert comment

With the Royal Horticultural Society revealing its top ten list of garden pests and diseases this week, Dr Joana Vicente from the University of Warwick School of Life Sciences has explained a little more about what makes these gardeners' troubles so problematic.

Dr Vicente said: "This list of top 10 garden diseases contains some pathogens that affect gardens and also orchards and parks - especially trees and shrubs - throughout the UK.

"It includes diseases caused by fungi, oomycetes and bacteria. In most of these cases, the diseases are very difficult to control and can kill trees and shrubs, cause reduction in fruit production, or affect their appearance as ornamental plants. Some diseases are also favoured by very humid weather and saturated soils, so the weather conditions have an impact on the frequency and severity of these problems.

"The number one is the honey fungus (Armillaria) that can kill the roots of woody and perennial plants. Phytophthora root rot (caused by an oomycete) can affect a large number of plants. Other pathogens listed are important on fruit trees, apple, pear and Prunus that include ornamental and fruit trees. Rose black spot can ruin the appearance of roses. Bacterial canker of Prunus can affect ornamental cherries and also fruit trees and even wild cherry trees and its importance varies from year to year, but trees have cankers and leaf spots that obviously affect the appearance and growth.

"Control of these diseases is difficult; gardeners will not want to apply chemicals and in many cases there are no chemicals available for garden use.

"Research that is being developed might lead to more biological control agents that could be useful for gardeners and breeding efforts might produce plants that are resistant to these pathogens."

13 March 2020

For interviews contact:

Peter Thorley
Media Relations Manager (Warwick Medical School and Department of Physics)


Tel: +44 (0)24 761 50868

Mob: +44 (0) 7824 540863