What’s Happening in Your Neck of the Woods?

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Fire Blight

Fire Blight is caused by the bacterium, Erwinia amylovora, and affects many members of the rose family (Rosaceae). Apples, pears, and crabapples are its most common victims, though it can also hit serviceberries, quinces, hawthorns, cotoneasters, and many others. Unfortunately, Colorado is witnessing an explosion of fire blight this year.

How can I tell if my tree is affected?

This disease is so-named because its progression causes leaves and any affected fruit to wilt, shrivel, and darken while remaining attached to the branches, giving the tree a fire-scorched appearance. The ends of infected twig shoots will dry and bend into a crook shape.

What can I do to prevent the spread of fire blight?

This bacterium overwinters in infected bark, and is impossible to kill once it has infected the plant. Instead, the cankers should be carefully pruned out in fall or winter when the trees are dormant


Aphids are common soft-bodied insects that use their slender mouthparts to suck out fluids from the stems and leaves of trees and landscape plants. While low numbers of aphids usually won’t kill a plant, when present in large quantities they can reduce the plant’s vigor and stunt growth. In warm weather, aphids develop from nymphs to adults in 7 or 8 days, and can produce up to 80 offspring a week. So a large aphid population can materialize in what seems like the blink of an eye!

How can I tell if my tree is affected?

These little sap-suckers often cause young leaves to curl and yellow. Also, aphids rid themselves of excess plant sap by excreting a sweet, sticky substance, known as honeydew, that grows into a sooty black mold.

What can I do to prevent the spread of aphids?

Treatments include a careful and well-timed application of dormant oil applied in the late fall or winter. The oil works by smothering overwintering eggs and adults, so a thorough application is necessary for success. Another option is to apply a “systemic” soil treatment in the fall, where watersoluble ingredients are applied around the tree’s root zone to be taken up by the roots and moved through the stem and leaf tissues with the water. This provides season-long aphid control.

Contact your SavATree arborist at the first sign of these destructive pathogens, so an appropriate prevention and management plan can be put in place on your property.

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