Tree Canker or Black Knot is caused by a fungus and affects a wide range of species including plums, cherries and apricots. Spore release is heaviest at blossom time. Prune and destroy infected branches before bud break.
Prune at least 2-4 inches below each knot. If pruning or removal of major limbs is not possible then you must cut away the knot down to healthy wood at least 1/2 inch beyond the knot.
Infected trees usually require pruning on an annual basis until the disease is completely eradicated. Knots will continue to grow until they girdle the branch and kill it. Severe infections can eventually kill the tree.
If you notice Black Knot on your trees, give us a call at your earliest convenience!
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