Now that Spring has sprung, tree disease and pest season is about to get into full swing.
In Utah, tree diseases and pests pose a concern from mid-March through the fall season. Although diseases and pests are most common with fruit trees, they can plague landscape and shade trees as well as ornamentals.
Although you may not be able to prevent all these problems, staying alert to potential warning signs can help prevent serious damage or death to your trees. Three pest and disease problems may be of extra concern for particular trees this year.
Leaf Scorch: A Physiological Tree Disease
Leaf scorch occurs when tree roots are unable to obtain the water necessary to supply the entire plant. It’s most common during dry periods with excessive heat or high winds. This tree disease commonly strikes broadleaf varieties including ash, elm, poplar and maple.
Watch for light-brown spots that appear first at the margins (edges) of leaves, eventually spreading across the entire leaf. This disease tends to strike younger leaves first, as they are more vulnerable. This condition is easily confused with iron-deficiency scorch, as the symptoms are similar.
Poor watering or a compromised root system is typically to blame for leaf scorch. Be sure to provide sufficient water during hot, dry periods, using a slow-soak technique. Prune dead leaves and branches, and apply a layer of mulch to help hold in moisture above the root system.
European Cherry Fruit Fly: A Looming Tree Pest Threat
The dreaded European cherry fruit fly was first detected in North America in 2016, and is expected to penetrate U.S. hardiness zones 2 through 9 — which includes all of Utah. A relative of the western cherry fruit fly, this tree pest primarily affects cherry, honeysuckle and snowberry trees.
This summer, the Utah Cooperative Agricultural Pest Survey team will closely monitor the region for any evidence of this invasive pest. Cherry fruit flies are active from May to early July. Look for soft, brown spots and the characteristic exit holes on fruit. In Europe, this pest is known to decimate 100 percent of the year’s cherry crop, left unchecked.
Using ground barriers, pesticides and diligent sanitation practices are the most effective ways to combat these tree pests.
Cytospora or Perennial Canker: A Shade and Fruit Tree Disease
Cytospora, also known as perennial canker, is a common but potentially devastating tree disease that attacks Utah shade and fruit trees. Cytospora is caused by a fungus that commonly plagues aspen, birch, willow and other broadleaf trees. Stone fruit trees, including apple, cherry, peach and apricot, are also vulnerable.
Watch for small bumps on trunks or branches, or sunken cankers that range in color from gray to brown. In more advanced stages, you may also see orange or brown masses or spores protruding from the pimple-like bumps.
Cytospora can’t be treated, but fortunately, it only attacks trees that are weakened. Combat this tree disease by keeping yours healthy and vigorous, and pruning to eliminate dead branches and wounds that may be susceptible to infection.
Reliable Tree Care, based in Murray, Utah, provides disease and insect control services throughout northern Utah. Our experienced arborists are trained to diagnose and treat problems to help ensure your trees stay healthy all year long. Because early detection is critical, contact us immediately if you suspect any type of tree disease or pest infestation.