Black knot fungus continues to infect Schubert Chokecherry trees, a popular species in Winnipeg. It strangles branches, blocking the flow of water and nutrients.
This year, the city is spending half a million dollars to remove and replant 600 of the trees. One of them is on Marvin Berndt’s property.
“Climb up the tree and chop those branches off to make it look nice again – that we won’t miss,” Berndt said. “But it’s always sad to see a tree go.”
There’s no cure for black knot. Regular pruning manages the disease, but the city said that’s not feasible due to the large number of susceptible and infected trees in the city.
“It’s the perfect storm for the spread of fungal disease in trees. You have a disease present, and lots and lots of susceptible hosts,” arborist Matt Vinet said.
Wind, rain, insects and animals can carry the fungal spores and with plenty of chokecherries in Winnipeg, finding a host is easy.
The majority of the trees are in neighbourhoods developed in the 1980s and 1990s, including Linden Woods, Whyte Ridge, Mandalay West, Valley Gardens, Springfield North, Dakota Crossing, River Park South, Mission Gardens and Richmond West.
“They’re everywhere. You go into some neighbourhoods like Tuxedo, it’s every tree. And you have boulevard plantings. It’s just endless,” Vinet said.
After this year’s cull, more than 7,000 of the trees remain in the city’s boulevard and park tree inventory.
The urban forestry branch discourages the planting of any new Schubert Chokecherry trees and homeowners are told to consult an arborist when dealing with infected trees.
