Many trees in our community can be infected by Black Knot Fungus – an air-borne fungus affecting trees in the prunus family. Schubert Chokecherry and Mayday trees in the City are particularly susceptible to the fungus, which looks like black clumps of coal that wrap around twigs, branches and even the trunks of trees in extreme cases.
Privately-owned Tree: If you notice the black growths developing on a tree on your property, please take steps to eliminate the fungus as soon as possible. This will help stop the spread of Black Knot fungus to other trees growing on your property and in our community. You can learn more about how to best remove Black Knot Fungus on the City of Calgary website.
City-owned Tree: If you notice Black Knot fungus developing on a tree owned by the City of Calgary, please contact 311 to request that the city address the situation immediately, to help stop the spread of the fungus.