3 Potential Tree Disease That Affect Cottonwood Trees

Posted on: 9 November 2015

Cottonwood trees are tall, broad trees that thrive in moist soil and are thus common in yards along rivers or streams. The bark is naturally grayish in color, and the leaves are triangular and green during summer before turning a bright yellow in the fall before shedding.

Cottonwoods are a homey, beautiful tree for any yard. But keeping your yard beautiful requires you to keep an eye on your cottonwoods for signs of disease and act accordingly to protect other trees in your yard from spreading diseases.

Powdery Mildew

Powdery mildew causes a thick gray fuzzy coating to form on the leaves of the cottonwood tree. The fuzz can start off light but then grow so thick the leaves can no longer take in sunlight. Leaves will prematurely turn yellow and fall off the tree.

While powdery mildew can make your cottonwoods look unsightly, the disease doesn't actually threaten the health of the tree beyond the leaves shedding. If signs of mildew are just beginning to show, trim off the affected leaves and the spread might stop there.

Lost most of your leaves early? Apply a fungicide to the tree before the next growth season to minimize the risk of the mildew coming back next year.

Heart Rot

Heart rot is a fungus-borne disease that causes small mushroom-shaped knobs to sprout up through damaged sections of bark. The rot only sets in where the bark is already damaged so healthy trees aren't at risk.

Ask a tree services company to remove any sections experiencing heart rot and any other damaged sections of the tree. Prevent recurrence next year with regular pruning to remove any damaged areas as soon as the damage occurs.

Wet Wood

Wet wood, also called slime flux, causes a smelly goo to discharge from damaged sections of the bark. The goo is thick and quite a bit can come out of even a small section of damage. But the goo is mostly a cosmetic and odor issue, as it doesn't cause any further damage to the tree.

Ask a tree trimming service to remove areas of wet wood as soon as the problem presents. You can add fungicide before the next growing season as a precaution, but trimming is usually sufficient to keep the slime from returning.

Always call out a specialist to diagnose your tree disease before taking any curative or preventative actions since the right course of action can vary greatly between diseases, which can often show similar symptoms.

For more information, contact Northwest Residential Arborist And Excavating or a similar company.


Keeping Your Trees Healthy

About a year ago, I realized that our front trees were starting to look a little funny. Some of the leaves were wilted, but we weren't anywhere near autumn. The bark on the trunk also seemed to be rotting away, which was frustrating and disappointing. Fortunately, a friend of mine told me to call a professional arborist for help. He came out, inspected the trees, and injected some special pesticides into the trunk. Within a few months, they started to look a lot better. Our arborist also trimmed our trees to reduce the weight load on the branches and to improve their shape. Check out this blog for information about tree trimming.