The parasitic fungus is known as ‘black knot’ and should be dealt with sooner rather than later as it can take only a few short years before it strangles the tree to death.
The owner of a local greenhouse describes the fungus as an olive shade of green when spores make their home in the cells of the host tree. Tree owners often mistake it as new wood on the tree. However, said Rob Sproule of Salisbury Greenhouse, it will eventually turn black and become very hard. Black knot chokes the living branch of the tree.
Flyer printing used by local greenhouses and even tree pruning companies can help alert homeowners to the threat of black knot in Edmonton.
Sproule issued advice to the public about how to spot the infection which mainly affects mayday trees and fruit trees. He said:
"Just look out into your trees and look for the silhouette, the thickened black, it almost looks like charred black rope is wrapped around it or burnt sausage links, something like that.”
Finding the fungus before it spreads and pruning the infected branches can usually save the tree. Last year, the city of Winnipeg launched an aggressive campaign to save thousands of chokecherry trees which had been planted in new neighbourhoods.
Infected branches should not be composted with other garden waste as the spores will spread and thrive. Sproule also recommends disinfecting pruning equipment after using it on infected branches.