What Is Fireblight

Fireblight is a tree disease that can affect many varieties of landscape trees and shrubs in your yard.  Correctly identifying this disease, and others, can be accurately diagnosed by your Best Edmonton Arborist.

Fireblight is a systemic, contagious bacterial tree disease that can destroy trees and shrubs that are in the Rosacea (Rose) family.  These include common specimens such as Apples, Crabapples, Mountain Ash, Hawthornes, Cotoneaster and Saskatoons in urban landscapes and commercial nurseries.    It is caused by the bacterial disease pathogen named Erwinia amylovora. 

The symptoms of this disease are quite typically easy to recognise, and usually can be identified on the newest fresh growth.  Spring flowers appear to be soggy and water-soaked, with new leaves wilted, appearing blackened along the veins. Branch tips start to hook over which is known as “flagging” or “shepherd’s crook”.  As the infection spreads and as the tissues further decline on the branches, the bark begins to appear sunken, water soaked and blackened.  Advanced infection develops into cracked, and entirely blackened branches, with the appearance of being “fire-scorched”.  Bacterial ooze may come from lesions on the bark, which can further spread infection.  This can be transmitted and spread by insects, birds, rain and wind distribution, as well as infected pruning tools. Plant tissue that has been damaged or injured, can also be susceptible to infection at these locations.

Fireblight Disease is spread most quickly during hot and wet weather.  It is mostly dormant during the coldest winter months, when the trees and bacteria are dormant.  The infection is carried from the point of infection through the tree’s vascular system and then systemically causes the demise of the tree.

Pruning, and removing to destroy all “infected” branches off your tree or shrub, with cleaned pruning tools, is crucial.  A sanitation solution of bleach and water, or bacteria-killing sanitizers, will be effective for cleaning your tools, between each pruning cut.   Always make sure that the diseased branches, and wood are disposed of correctly at the local landfill, and never use diseased mulch or wood chips in your landscape.

To aid in correct disease diagnosis and identification of the plants and trees in your yard, contact your Edmonton Arborist.