Many homeowners wonder if their trees are healthy or quietly suffering from a disease or insect infestation. They look at their tree trying to interpret signs and signals but don’t know if what they’re seeing is a sign for concern. They ask themselves: Is that leaf with spots a bad sign? Is that one branch that has no leaves a sign of an infection or infestation? Am I overreacting? If you find yourself worrying about your tree, we can help. Read on to learn the most common warning signs that indicate your tree is stressed, diseased, or infested with insects.
1. Leaf Spots & Holes
Spots on your leaves or holes in them is a telltale sign of disease. Spots may vary in size with some being circular while others will be irregular or blotchy. The majority of leaf spots are caused by fungal infections; however, there are certain bacterial diseases that cause spots on leaves as well. Some insect damage can also create damage that resembles leaf spot diseases. If your tree has holes in its leaves it is most likely suffering from shot hole fungus or an insect infestation that is feeding on the leaves.
2. Tree Cankers
Tree cankers are dead sections of bark. These can occur on branches or the trunk of the tree, wherever there is bark. Cankers are a sign of injury to the tree, a fungal infection, or a bacterial infection. If left untreated cankers can cause extensive damage, killing certain areas of the tree, and the entire plant if the canker is on the main trunk.
3. Canopy Dieback
Canopy dieback refers to the decline of a tree’s canopy. When you step back and look at your tree it may look sparse and not as full as other trees during this time of year. Canopy dieback is a sign of overall health decline. This can be caused by an insect or disease, old age, stressors such as drought, extreme weather, and soil compaction. If your canopy dieback is isolated to certain sections of your tree it could be a sign of borers such as the ambrosia beetle, emerald ash borer, and Asian long-horned beetle.
4. Early Leaf Drop
Early leaf drop refers to the leaves of your trees falling during the spring and summer. It is important to notice this symptom as it is often associated with serious root and soil disorders. Early leaf drop can also indicate vascular diseases and boring insects.
5. Honeydew & Sooty Mold
Honeydew is a clear sticky substance that resembles sap. It is one of the most noticeable signs of insect infestation. Honeydew itself is the excrement from plant sucking insects, such as aphids, lace bugs, and scale. If you develop a honeydew problem you will most likely notice sooty mold as well. Sooty mold is a fungus that grows on top of honeydew and coats the leaves of your trees to the point where they can no longer absorb sunlight. This means that the process of photosynthesis is interrupted and the tree will not be able to produce the nutrients they need for survival.
6. Yellowing/Brown Leaves
Yellowing and brown leaves are one of the first noticeable signs your tree is having an issue. Many homeowners don’t get up close to their trees enough to notice more subtle signs; however, yellow and brown leaves can stand out against the green of other trees. Yellowing and brown leaves can be a sign of nutrient deficiencies, drought, heat stress, winter burn, and certain types of insects.
7. Tree Cavities
Trees can develop cavities, holes, and hollows in the trunk of the tree, for many reasons including injuries, stress, over mulching and buried root collars. These culprits can lead to vascular collapse within the tree and decay pockets around the lower trunk wood. Cavities used to be treated by filling them up; however, this is now advised against as it can ruin the structural integrity of the tree over time and lead to fungal growth. Although there is no treatment, cavities should be regularly inspected by an arborist because if the cavity is too large the tree may need to be taken down.
8. Mushrooms At Base Of Tree
Mushrooms located throughout your yard, far away from the trunk of your tree, are typically no cause for concern. However, mushrooms located at the base of your tree are likely to be a problem. Mushrooms growing at the base of a tree is a common sign of root rot, and interior decay. These types of fungi and decay can cause trees to uproot easily during storms and high winds.
These are some of the most common signs that your tree is stressed, dealing with an insect infestation, or diseased. If your trees and shrubs are exhibiting these signs give us a call at 703-573-3029 or book a consult online. However, keep in mind this is not an exhaustive list and your tree could exhibit other less common signs of issues. If your tree is exhibiting any signs that worry you call one of our arborists to have them evaluate that tree.