The Denver Post reported on November 2018 that Fire Blight is on the move across the Front Range. Click here to read the article. Fire Blight is a bacterial disease that affects certain tree species in the rose family, including apples, pears, and crabapples. The pathogen thrives when spring temperatures are wet and warm. The Denver Area has had many warm springs in the last decade, so Fireblight has been running rampant for years.  

The bacterium Erwinia amylovora causes Fire Blight. When the temperature gets in the 60s in the spring, the bacteria begin to multiply rapidly, forming a bacterial ooze that forces its way onto the bark surface. Insects become unwilling carriers of the disease as the ooze sticks on their bodies, and they visit other parts of the tree or other apple or pear trees in the neighborhood. Also, rain and hail splashes spread the pathogen to other parts of the tree.  

fireblight lifecyle

Fire Blight Symptoms 

The microorganisms grow fast in blossom nectar and start to invade adjacent branch tissue and twig terminals. Later in the spring, the blossoms on affected trees appear water-soaked and turn brown quickly. Dead trigs and leaves curl-up and form a Shepards’s crook, which is a telltale sign of Fire Blight. Also, an affected tree’s fruit remains attached to the tree in the fall.

fire blight shepards crookDisease Management

If a homeowner is planting apple, pear and crabapple trees, be sure to ask the tree or garden store for tree varieties resistant to Fire Blight. Avoid fertilizing the trees with high nitrogen products to avoid excessive twig growth. Annual structural pruning of the trees will promote healthy growth. Healthy trees fight off infections better than unhealthy ones.

Fire Blight Treatment

The best treatment for a tree infected with Fire Blight is situational. It depends on the extent of the infection, time of year, and other factors. We recommend calling a professional tree service company, like Ross Tree, for the best possible Fire Blight treatment outcome. 

Fire Blight Tree Pruning

The Ross Tree arborist or plant health care professional with sharp tools, disinfectants, and know-how will cut the branches and remove cankers in a manner to reduce infection. Winter is a good time for Fire Blight treatment because there is no need to sterilize the tools between cuts. Our pruners avoid any unnecessary wounds to the tree.

fire blight ooze

Other Treatment Choices 

  • Blossom Sprays
  • Antibiotics
  • Copper Based Products
  • Biological Products

Some apple and pear trees are beyond treatment and need to be removed safely. Need to know your Fire Blight treatment options? Ross Tree is at your service. Click here to request tree service or call 303-871-9121 for an appointment.