Tree pests and disease
Ash Dieback disease
Ash dieback is a serious disease of ash trees caused by the fungus Chalara fraxinea. The disease causes leaf loss and crown dieback in affected trees and it can lead to tree death.
Currently. the advice is that mature trees should not be removed, as they are valuable to wildlife, take longer to die and can help us learn more about genetic strains that might be resistant to the disease. Infection does not occur directly from tree to tree.
The disease can be spread from spores from the fungi attached to leaves and leaf litter, spores can also be spread by wind and rain.
Oak Processionary Moth (OPM)
Oak Processionary Moth (OPM) is an introduced pest and has spread throughout west London and has now been confirmed in several sites in Barnet. This is currently being controlled by the Forestry Commission. The caterpillar can cause defoliation of oak trees (all species) but does not make them dangerous. The hairs of the caterpillars can cause allergic reactions in people and animals.
More information can be found with the Forestry Commission.
Following the introduction of the above pests and diseases, Barnet have implemented biosecurity measures to manage the risk of importing diseases by sourcing trees for planting that are not imported directly from mainland Europe.
Our trees spend one year at a UK nursery to allow any manifestation of disease to become apparent before planting on.