Apple Scab is a common disease of Crabapple trees. It is a COSMETIC disease - while it is unsightly, it does not kill the tree. All of the crabapple varieties we sell here at the Barn are disease resistant varieties. However, even resistant varieties can occasionally get Apple Scab: in summers of extreme heat and humidity, when they are newly planted or stressed.
Symptoms: Leaves develop a black spot, yellow, and then drop.
We Recommend: To PREVENT Apple Scab on CRABAPPLES, spray trees with INFUSE in early spring as leaf buds begin to swell (before leaves fully emerge). For best coverage, spray again after the tree is done flowering. Spraying in late spring is better than not spraying at all, but do not spray while the tree is in full bloom to avoid harming pollinating insects. If a tree already has symptoms (black spots & dropping leaves) it is too late to treat – spray the following spring.
Why INFUSE?: It is a very effective systemic fungicide – it won’t wash off and lasts up to a month. It comes as a concentrate if you own a hose-end or pump sprayer OR an easy Ready-to-Use bottle you simply attach to you hose and turn on.