Tree Issues that are Common in the Treasure Valley

Tree chlorosis disease in Middleton, Idaho

Trees and landscapes often get neglected due to busy schedules and lifestyles. They get planted and cared for during the first year of getting established, but this care and maintenance tends to taper off. If trees and shrubs are planted and left alone, they will fall victim to disease or insect invasion at some point, especially if they are types that are more susceptible.

To protect your investments, it is far better to attend to their care and protection on a regular basis to stay on top of any tree issues.

Here are several common tree issues in the Treasure Valley:


Chlorosis disease on tree leaves in Middleton, Idaho

Tree chlorosis is a condition characterized by the yellowing of leaves due to insufficient chlorophyll production, a vital pigment responsible for photosynthesis. This yellowing is a visible sign of the tree’s inability to produce an adequate amount of chlorophyll, which is crucial for converting sunlight into energy.

Chlorosis can result from various factors, including nutrient deficiencies, particularly iron or manganese, poor soil drainage, compacted soil, or root damage.

As chlorosis progresses, affected leaves may become pale or yellow, starting from the veins and spreading across the leaf surface. If left unaddressed, severe chlorosis can weaken the tree, making it more susceptible to diseases and environmental stressors.

Effective management involves identifying and addressing the underlying causes, such as nutrient supplementation, soil improvement, and proper irrigation, to promote the tree’s overall health and vigor.

Fire Blight

Fire blight disease damage on tree leaves in Middleton, Idaho

Tree fire blight, caused by the bacterium Erwinia amylovora, is a highly destructive and contagious disease that primarily affects members of the rose family, including apple and pear trees. This bacterial infection induces symptoms such as wilting, blackening of leaves, and the appearance of burnt-looking shoots, resembling the aftermath of a fire.

The bacterium spreads through various means, including rain splashes, insects, and contaminated pruning tools, making it a challenging pathogen to control. Fire blight thrives in warm and humid conditions, with outbreaks commonly occurring during periods of high moisture.

Once infected, affected branches often exhibit a characteristic shepherd’s crook shape. Effective management involves pruning and removing infected branches, applying antibacterial sprays, and employing preventative measures during susceptible growth stages.

The economic impact of fire blight on orchards underscores the importance of implementing stringent disease control strategies to mitigate its spread and protect fruit-bearing trees.


Borer holes and borer insect damage on trees in Middleton, Idaho

There are a few different types of borers in the Treasure Valley. They are invasive wood-boring beetles that feed primary on birch and ash trees. This insect’s larvae feed on the vascular tissue of the tree affecting its ability to transport water and nutrients.

Cottony Maple Scale

Cottony maple scale on a tree in Middleton, Idaho

Cottony maple scale (Pulvinaria innumerabilis) is an insect pest that poses a threat to various species of maple trees, as well as other ornamental trees and shrubs. These small, flat, oval-shaped insects are often found clustered on branches and twigs, resembling small cottony masses.

Cottony maple scale feeds on the sap of the host tree by inserting needle-like mouthparts into the plant’s vascular system. As a result, infested trees may exhibit symptoms such as yellowing of leaves, premature leaf drop, and reduced overall vigor.

The cottony, waxy substance produced by these scales serves as a protective covering for their eggs and provides some defense against natural predators.

Regular monitoring and early intervention are crucial in preventing the widespread infestation of cottony maple scale and preserving the health of affected trees. This insect leaves a sticky honeydew beneath its canopy which attracts wasps. A noticeable 1/4″-1/2″ white egg sac that looks like a cotton ball is the symptom to look for.

Tree Sunscald

Sunscald tree damage in Middleton, Idaho

Tree sunscald, also known as southwest injury or winter sun injury, is a condition that occurs when the bark of a tree is exposed to sudden and intense sunlight, particularly during winter or early spring. This phenomenon often affects deciduous trees with thin bark, causing damage to the living tissues beneath.

Sunscald typically occurs on the tree’s southwest-facing side, where the sun’s rays are most intense. The sudden warming during the day can stimulate cell activity, while rapid temperature drops at night can lead to cell damage and bark splitting.

Common symptoms include sunken and discolored areas on the bark, which may later develop into cankers. Sunscald can weaken the tree, making it more susceptible to diseases and pests.


Aphid pest damage on tree leaves causing aphid leaf curl in Middleton, Idaho

Tree aphids, small sap-sucking insects belonging to the Aphididae family, can be significant pests for various tree species. These tiny, soft-bodied insects feed on the sap of trees by piercing the plant’s vascular system with their needle-like mouthparts.

Aphids reproduce rapidly, and large infestations can lead to detrimental effects on the host tree’s health. Affected trees may display symptoms such as curling or yellowing of leaves, stunted growth, and the development of a sticky substance known as honeydew on leaves and branches. Honeydew can attract other pests, such as ants and sooty mold, further complicating the tree’s well-being.

Early detection and appropriate intervention are essential for maintaining the vitality and resilience of trees in the face of aphid infestations.

Incorrect Pruning Practices

Improper tree pruning

Incorrect tree pruning can have severe consequences for the health and structural integrity of trees. Improper pruning techniques, such as topping or excessive crown reduction, can lead to the development of weakly attached branches, making the tree more susceptible to breakage during storms or adverse weather conditions. Stub cuts and improper pruning wounds create entry points for pests and diseases, increasing the risk of infections that can spread throughout the tree.

Additionally, over-pruning can stress the tree, deplete its energy reserves, and compromise its ability to photosynthesize effectively. This, in turn, may result in a decline in overall tree health, with symptoms including leaf dieback, diminished growth, and increased vulnerability to environmental stressors.

Tree Girdling

Tree girdling issues in Middleton, Idaho

Incorrect tree planting processes, including the negligent practice of leaving tree wiring or fabric on, can have detrimental consequences for the long-term health and development of newly planted trees.

When wires or fabric wraps are not properly removed after planting, they can constrict the growth of the tree, leading to girdling—a process where the material cuts into the bark as the tree expands in girth. This impedes the tree’s nutrient and water transport systems, compromising its overall vitality and increasing the risk of disease or pest infestation.

Additionally, retained materials may inhibit the natural development of the root system, restricting the tree’s ability to establish a stable foundation in the soil. To ensure the success of tree planting initiatives, it is crucial to adhere to proper planting procedures, which include the thorough removal of any support materials to facilitate the tree’s healthy growth and resilience in its environment.

Incorrect Watering Practices

Incorrect tree watering practices can have detrimental consequences for the health and stability of trees. Overwatering, where the soil remains consistently saturated, can lead to oxygen deprivation in the root zone, causing root rot and adversely affecting the tree’s ability to take up nutrients. On the other hand, underwatering can result in drought stress, causing leaves to wilt, turn brown, and eventually drop.

Both overwatering and underwatering can compromise the tree’s resilience to pests and diseases, making it more susceptible to environmental stressors. Inconsistent watering patterns may also contribute to the development of shallow root systems, reducing the tree’s stability and resistance to wind and other adverse weather conditions.

There are a lot of different types of trees in the Treasure Valley and each one has unique needs and challenges. We can stay ahead of most problems with a regular maintenance program that includes pruning, fertilization and insect protection. Some trees will require additional specialized treatments.

Give us a call today if you have any tree concerns or would like to take advantage of our tree care services, call 208-585-9400.