Premature Leaf Drop Affecting Norway Maple Trees

Peterborough, ON – Residents may notice Norway maple trees losing their leaves earlier than usual this summer. City arborists are seeing signs of decline and premature leaf drop on Norway maples throughout the community and have received reports of similar conditions across southern Ontario. 

Staff believe the premature leaf drop is largely associated with environmental stress, including the lingering effects of last year's drought and periods of extreme heat this summer. An increase in decline and early leaf drop in Norway maples was also observed during the heat wave in July. 

Many affected Norway maples are showing signs of tar spot, a common fungal disease that causes dark spots to develop on maple leaves. While tar spot can affect the appearance of trees and contribute to early leaf drop, it does not typically cause serious or permanent damage to otherwise healthy trees. 

Trees showing signs of stress or losing their leaves early are not necessarily dead or dying. The effects of drought stress can continue beyond the year in which the drought occurred, and staff are hopeful that affected trees will recover and show healthier foliage next year. 

Residents with maple trees affected by tar spot can also help reduce the likelihood of infection the following year by raking and removing fallen leaves.  

The City collects leaf and yard waste weekly on regular collection days until the end of November. Leaves can be placed at the curb in brown paper yard waste bags or approved reusable containers. 

For more information about leaf and yard waste collection, including set-out requirements, visit peterborough.ca/yardwaste.