Aspens are susceptible to many problems in the urban landscape.
One of those problems is aspen leaf spot, a disease caused by fungus. Aspen leaf spot, or Marssonina leaf spot, is common on aspen trees in the late summer and autumn. A previous spring of warm, rainy conditions creates the perfect environment for the disease to spread. When affected by the disease, black spots develop on aspen leaves. However, black spots may develop for a variety of reasons, so it's important to recognize all of the symptoms of aspen leaf spot.