April 30 2021
HAMILTON, ON – This spring, the City of Hamilton is sharing resources and tips with residents about tree care and how to effectively manage invasive species on their property.
Listed below are some tips on identifying invasive species and tips for proactive and reactive tree protection.
Although not detected in Canada to date, Oak Wilt is an invasive fungus that affects the flow of water and nutrients in oak trees causing the leaves to wilt. Red oaks are the most susceptible, however, it can impact bur oaks and white oaks.
Spring is the most likely period of infection as the warmer weather attracts bark beetles who spread the fungal spores to neighbouring oak trees. The City encourages residents to avoid trimming their own oaks until the fall. If pruning needs to be done before the fall, wound paint should be applied immediately to fresh cuts.
Physical signs of Oak Wilt include:
- Discolouration of leaves beginning at the top of the tree
- Wilting and browning of leaves
- Premature leaf fall
- White, grey or black fungal spots on the trunk of the tree, sometimes emitting a fruity smell
If Oak Wilt is suspected on privately owned Oak trees, residents are advised to report to the Canadian Food Inspection Agency. If Oak Wilt is suspected on publicly owned trees, please call the Customer Contact Centre at 905 546 CITY (2489).
European Gypsy Moth (Lymantria dispar dispar)
The European Gypsy Moth (Lymantria dispar dispar) is an invasive species that has quickly spread across southern Ontario. The moths prefer oak trees but will feed on a variety of hardwood tree species including maples, beech and walnut.
European Gypsy Moth (Lymantria dispar dispar) eggs hatch in the spring and as the caterpillars grow, they begin feeding by cutting holes in leaves and if infestation is severe, eating the entire leaf.
Homeowners are encouraged to monitor their hardwood trees year-round. For tips on identifying European Gypsy Moth (Lymantria dispar dispar) and removing them safely, visit hamilton.ca/europeangypsymoth
If European Gypsy Moth infestations are suspected on publicly owned trees, please contact the Customer Contact Centre at 905 546 CITY (2489) to be connected with the City’s Forestry Operations Centre.