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Residents urged to keep an eye out for black knot fungus

Just before the long-awaited spring bloom, Red Deer residents are reminded to be on the lookout for tree fungus easily visible at this time of year.
WEB-Black-Knot-Fungus
City of Red Deer parks labourers

Just before the long-awaited spring bloom, Red Deer residents are reminded to be on the lookout for tree fungus easily visible at this time of year.

The black knot fungus can deform and infect mayday, schubert choke cherry and choke cherry trees. The fungus can be seen much easier before the leaves bud out.

Susan Katzell, City of Red Deer urban forester, said parks staff have been out in full force catching the fungus that is native to the area.

“Infection rates do increase and then we knock that back by pruning it out,” said Katzell. “It will never eradicate it completely because it is always around.”

Small black spindle-shaped swellings, called knots, are found on branches or twigs. The fungal disease has increased in municipalities across the province.

The city has had an ongoing program for decades to manage it on their trees. City crews trim the trees around the fungus to prevent the spread as much as possible. Fungal spores are carried by wind and rain to new sites.

To curb the spread of the black knot fungus, people are asked to trim the infected branches and twigs about 10 to 15 cm (four to six inches) in from the swelling. Then people should take the cut-off branches or twigs to the city landfill and dispose of the material in the garbage, not the compost or yard waste part of the landfill.

“It’s an ongoing maintenance program we have done for years now,” said Katzell of trimming trees on city-owned land.

“We have to follow the severity of the infection around the city.”

Residents are asked to take action on infected trees on their property to reduce the spread of the fungus to other trees throughout the city.

“Once you get your tree clean, usually you can keep it clean for a number of years,” said Katzell. “If the humidity is right and there is a spore, or it rains at the right time, it can come back.”

For more information the city’s website, www.reddeer.ca, has a list of tree pests and details on how to identify them and what to do about them.

mcrawford@www.reddeeradvocate.com