Until this spring, I had a lovely Mayday tree in my front yard. This tree is very early to bloom and is covered with fragrant white flowers making a dramatic display after a long prairie winter. However over the past 3 years or so it had developed an infection with black knot fungus. I had been pruning out the affected areas diligently, and cleaning my tools as recommended to prevent further infection. Much to my dismay, this year the tree did not leaf out or have any flowers. The time had come to replace the tree.
Black knot fungus is caused by Apiosporina morbosa, which is endemic in this area and affects plants in the genus Prunus. This includes cherries, plums, flowering almond, apricot, and Mayday trees. All of the boulevard trees (Schubert Chokecherry) in my neighbourhood have black knot. As the galls produced from the infection release additional fungal spores, it was an uphill battle to keep my tree free of black knot.
Black knot fungus is caused by Apiosporina morbosa, which is endemic in this area and affects plants in the genus Prunus. This includes cherries, plums, flowering almond, apricot, and Mayday trees. All of the boulevard trees (Schubert Chokecherry) in my neighbourhood have black knot. As the galls produced from the infection release additional fungal spores, it was an uphill battle to keep my tree free of black knot.
The gall is an unsightly black mass that can eventually girdle the tree and kill it.
Needless to say, I have replaced my Mayday tree with a flowering crabapple which is not susceptible to black knot fungus.
Needless to say, I have replaced my Mayday tree with a flowering crabapple which is not susceptible to black knot fungus.