Almost everybody can appreciate the beauty and shade that trees bring to a residential yard, especially when the sweltering heat of summer rolls around. Trees also make a value-rich commodity when the time comes to sell your home. Diseased trees, however, will have the opposite effect, being both a visual detraction and a potential source of problems and expense.
Unfortunately, by the time many homeowners realize that they are dealing with a diseased tree, the problem has gone on too long to treat. If you would like to protect your investment in trees by learning more about common diseases, read on. This article will arm you with important information about two common diseases affecting southern Tennessee trees.
Anthracnose represents one of the most common - and confusing - of all tree diseases. Much of the confusion stems from the fact that anthracnose does not denote a single disease. Instead, the term acts to categorize a variety of different fungal based diseases that tend to manifest in similar ways. The symptoms of an anthracnose problem may include any of the following:
- Brown spots or blotches on leaves
- Leaf and branch dieback
- Orange brownish twig cankers
- Shoot blight
The fungi responsible for anthracnose are capable of attacking a wide variety of trees, including ash, birch, elm, maple, and oak. Wet weather tends to trigger anthracnose breakouts. The spores are capable of over-wintering on a tree, making the tree stay dormant until the next period of moist spring weather.
Anthracnose will not usually kill a tree outright. This disease is more of an aesthetic problem. Yet, a tree that suffers from anthracnose will become progressively weaker, making the tree more vulnerable to other, potentially terminal diseases. For this reason, attempt to control an anthracnose outbreak when it occurs.
An arborist may choose to apply fungicide to help treat a persistent anthracnose problem. Sprayed onto a tree's leaves before any symptoms of anthracnose have occurred, fungicide will effectively kill any spores that may be present. Care should also be taken to avoid wetting trees unnecessarily, as this will increase the risk of an outbreak. Be sure to redirect sprinklers so that they do not soak low lying branches.
2. Powdery Mildew
Powdery mildew is one of the easiest tree diseases to recognize. True to its name, this disease manifests as a white or grayish fuzz or powder on the leaves of a tree. This powder consists of millions upon millions of microscopic fungal spores. These airborne spores are capable of traveling from an infected tree to other trees in the vicinity.
Powdery mildew attacks a variety of different trees, including any of the following:
As a powdery mildew infestation grows worse, you may notice that, beneath the white powder, your tree's leaves seen to be turning red, purple, and other odd colors. Eventually, they will become yellow and begin to fall. The white powder may also become dotted with tiny black or orange balls. These are the new spore balls produced as the fungus continues through its lifecycle.
Like anthracnose, powdery mildew flourishes in cool, moist conditions. Prone to strike in the spring and fall, it favors trees growing in shady areas, as the lack of sunlight means they will remain cooler throughout the day. Good sun exposure and air movement keep powdery mildew at bay.
Even well-placed trees may succumb to powdery mildew, however. Outbreaks may be treated by spraying the affected tree with either wettable sulfur or a fungicidal solution. Deciding on the best treatment option should be left to a professional arborist. If you believe that one or more of your trees are suffering from such a disease, please don't hesitate to contact the experts at Joe Webster Tree Care, Inc.