This includes branches killed by borers, scale insects or canker diseases. Dead branches and stems often attract insects and diseases. Rake and remove all leaves from plants infected by leaf spot diseases. Note heavy scale, aphid or spider mite infestations. If your trees or shrubs were injured by these insects this year, consider an application of dormant spray oil this winter or in early spring before new foliage appears.
Good management can prevent most insect and disease problems.
When pest problems do appear, obtain an accurate diagnosis from a specialist before starting any kind of treatment. Contact your local Colorado State University Cooperative Extension office for this service, as well as for non-biased, research based information.