Are Denver Trees at Risk of Fire Blight?

Fire blight Erwinia amylovora) - Fielding Tree Denver fire blight

Spring is here and that means trees across Denver are starting to bloom. It also means the risk of fire blight is on the rise. We help homeowners fight the effects of fire blight on apple, crabapple, and pear trees. Fire blight moved through the Denver metro area in 2014 and continued south into Douglas County in 2015.

What’s fire blight and what are the signs of fire blight?

Fire blight is a bacterial diseases that presents itself through dead branches, water-soaked blossoms, and the telltale sign of a brown or even black ‘burned’ appearance. This is where fire blight get its name because trees affected by fire blight often look like they were burned. Since fruit trees are largely affected by fire blight, dried fruit on a tree can also be a sign of fire blight’s effect.

When is the greatest risk of fire blight?

Spring is the most notorious time for fire blight to make its mark. The bacterium Erwinia amylovora finds its winter hibernation in blighted trees. As soon as spring temperatures reach around 65 degrees Fahrenheit, the disease starts its rapid multiplication process. Enormous amounts of bacteria are secreted out the infected tree’s bark pores and other openings.

Insects, such as beetles, aphids, ants, bees, and others, are drawn to the fire blight’s secretion, which is a type of sticky gum. These insects transfer the sticky ooze to other tree’s blossoms over time and the fire blight continues spreading. Fire blight can also be transferred to other trees through splashing raindrops.

What are the treatment options for fire blight?

Unfortunately, there is no known cure for fire blight. This means prevention is the most important method to help limit the spread and threat of fire blight to surrounding trees. There are select varieties of apple, crabapple, and pear species that are more resistant to fire blight. Our Fielding Tree Care team can help you identify which fruit tree species may be the best match for your property.

Preventative measures against fire blight often include pruning. We do not recommend pruning fruit trees during bloom. This can inadvertently spread fire blight pathogens during the pruning process and also leave infected residue on pruning equipment that needs to be carefully cleaned to avoid spreading the disease. Pruning infected trees during the summer means your trees are in full bloom and any infected fruit is visually compromised.

Some arborists use a chemical spray as a preventative measure. We do not endorse using chemical sprays during bloom because of the potentially harmful effects of the spray. Chemical sprays can easily contaminate the fruit on the tree and be harmful to anyone who eats the fruit.

There are several safe and effective preventative treatments endorsed by Fielding Tree Care. If your trees are showing signs of fire blight, please schedule a complimentary on-site inspection with our team.

Fielding Tree & Shrub Care serves homeowners with tree services in Highlands Ranch, Littleton, Centennial, Lone Tree, south Denver, Castle Rock, Parker, and the rest of Douglas County.