As the 2010 growing season draws to a close, it is time to look back and examine the wild weather ride that we had this year. Our trees and shrubs have certainly been impacted by the dramatic climate patterns that we have had.
According to the State Climatology Office, the weather of late March and early April was the warmest in the past 120 years in certain Wisconsin locations, and the spring season started quickly and early this year. The warm weather and more than adequate rain created some of the best spring blossoming that has been seen in a long time. Plant growth this spring and summer has been exception, bordering on “out of control” in some people’s minds.
Violent weather this summer brought us floods and severe thunderstorms. High winds and lightning strikes damaged many trees. Flooding, saturated soils, and poor drainage have caused root decay and stress on trees.
The rain and humidity this season also has
made conditions ripe for an abundance of fungus issues for trees and shrubs. Fungal diseases typically cause spots or black/brown markings on leaves and lead to premature leaf drop. Fortunately most trees have ample energy reserves, allowing them to cope with leaf diseases, but for trees already stressed by other problems, leaf diseases can spell real trouble. Below is list of some common tree species that were hit hard with fungal disease this year.
- Flowering crab trees– Apple scab disease tends to attack these trees on a yearly basis, but the disease has been exceptional vigorous this season. Hoppe Tree Service performs foliar spray programs to protect crab apple trees. The program consists 2-3 separate applications timed about 3 weeks apart, starting in spring.
- Spruce– There are two common fungal diseases which attack spruce trees. These diseases typically start lower on the tree and slowly move upwards, killing the tree as it goes. Often increase light penetration to the tree and pruning can help. Repeated fungicide applications during the growing season can also make a difference.
- Norway maple– Numerous leaf disease have afflicted maples this season. Tar spot, powdery mildew and many others. Although unsightly, these leaf spot diseases are relatively benign to the health and vigor of your tree since most infections occur late during the growing season. Therefore, treatment is often unnecessary.
In dealing with fungal diseases, there are several cultural practices that you can implement to help minimize future infection: (1) Maximize airflow and direct sunlight to your tree by pruning the tree, or pruning surrounding trees. (2) Rake and dispose of fallen leaves during autumn to remove the fungal spores (3) As necessary, increase the vigor of your tree by proper watering, fertilizing, and pruning. Hoppe Tree Service can provide these services to help keep your trees healthy and strong.
Certified Arborist WI-477A