Catch this common tree disease before it takes a toll on your tree.
Healthy apple trees can change quickly when disease gets established. If you notice olive-coloured spots on the leaves of an apple or crabapple tree, it may be more than a cosmetic issue. Apple scab is a common fungal disease that affects apple and crabapple trees and can become particularly noticeable during cool, wet spring conditions.
Apple scab is caused by the fungus Venturia inaequalis. It affects both leaves and fruit, with symptoms developing as the growing season progresses. The disease overwinters in fallen leaves, producing spores in spring that can spread through wind, rain, and other moisture. This means what happens during fall cleanup can influence disease pressure the following year.
Common signs of apple scab include:
- Olive-green or brown spots on leaves
- Velvet-like spots with darker or fringed edges
- Spots that become larger and darker over time
- Yellowing leaves with premature leaf drop
- Olive-green spots appearing on fruit
- Deformed or cracked fruit in more severe cases
Repeated or severe leaf loss can weaken a tree over time. Cool, wet conditions during leaf emergence can encourage infection, which makes spring an important time for monitoring apple and crabapple trees. At WillowStone, our approach to disease control starts with diagnosis. We assess the tree and its growing environment before recommending a treatment or maintenance strategy. This approach helps us distinguish apple scab from other problems that can cause spotting, yellowing, or premature leaf loss.
If you are seeing signs of apple scab on the trees around your Collingwood, Ontario property, don’t ignore them. Connect with our experts to arrange an assessment and find the right approach for protecting your trees.
At WillowStone, we can help treat trees that have apple scab for residents of Collingwood, The Blue Mountains, Wasaga Beach, Meaford, and Thornbury, Ontario.