By: Ash Davidson
Ever walked through the river valley, or took a stroll around your neighbourhood, and noticed black growths on some trees? You’re likely seeing black knot (Apiosporina morbosa). Black knot is a fungal disease that targets plant species in the genus Prunus. The most noticeable characteristic of black knot is the mature, black swellings on branches. During the summer months, when temperatures are high and rain is falling, an incredible amount of spores are released and are spread by animals, wind, or rain. It takes approximately 2-3 years for the fungus to reach the mature stage. If left unchecked, the fungus will eventually kill the host tree, so early management and control is necessary.