The Dreaded Black Knot

  Have you ever seen a bush that looks like it has poop all over the branches?

    Cherry, plum, apricot, and chokecherry are some of the most common shrubs in the Midwest because they grew some of the few types of fruit that survives in this climate. However, you may have noticed a black yucky-looking substance all over on them at some point. Dibotryon morbosum, also known as "black knot", is a disease that encompasses these certain types of shrubs.

    Black knot is caused by the fungal pathogen Apiosporina morbosa and affects primarily trees of the Prunus genus. It appears to have a black, rough texture often resembling 💩 or swollen, elongated knots. Some prevention steps for this disease include pruning, sanitation, and maximizing tree health. In other words, regular inspection of shrubs is crucial to prevent the spread of this disease. To treat black knot, you can cut off the affected branches, and/or spray the shrub with fungicides. It can injure different shrubs in various ways, so there may not be a one size fits all solution for this disease. Contact your local extension office to get the best treatment plant for your affected shrub.

    Wear PPE (proper protective equipment) when working with shrubs thought to have the black knot disease. It can cause irritation on your skin if exposed.

Although it looks dreadful, Black Knot does not always kill the shrub.