... hickory, walnut, birch, oak, and ash are susceptible. Ash dieback. Tree surgeon arboriculturalist cutting down a diseased ash tree with the aid of a tractor to pull the falling tree safely. It was detected in the UK for the first time in 2012 and is now very widespread. These University of Arkansas fact sheets FSA7533, Anthracnose Diseases of Common Landscape Trees, ... Black knot is an occasionally lethal disease of the Prunus. All ash trees are susceptible to emerald ash borer (EAB). The stately ash tree (Fraxinus spp.) We offer free resources for helping to diagnose tree disease and our agents can offer advice on treatment. The cottony ash psyllid — also known as jumping tree lice — has been added to a list of threats to Winnipeg trees, which also includes the emerald ash borer and Dutch elm disease. is used as a street tree in many areas and has also been prized as a yard tree for its generous shade in summer. Dead tree trunk showing tracks of emerald ash borer larvae. Many people believe that someone may have dumped ashes or may have even caught the plant on fire when they first see this plant mold. Hymenoscyphus fraxineus causes a lethal disease of ash and represents a substantial threat both to the UK’s forests and to amenity trees growing in parks and gardens. Most plants affected by this plant mold growth will also have some sort of pest problem. Disease-resistant elms are commonly-recommended to replace ash. Most ash tree diseases can be identified as one of two types: foliar or vascular. Black knot fungus - large knots (abnormal growths) of bark that encircle the branch. Bronze leaf disease (BLD) - effects certain poplar and aspen trees. It’s the larvae that cause … Catnap72 / Getty Images Common Pests/Diseases . Black ash trees (Fraxinus nigra) are native to the northeast corner of the United States as well as Canada.They grow in wooded swamps and wetlands. Your plant’s twigs, branches or leaves will be covered in a grimy, black soot. According to black ash tree information, the trees grow slowly and develop into tall, slender trees with attractive feather-compound leaves. Mature ash tree suffering disease and dieback with bark beginning to peel of the trunk to a young 14m tall tree and mature forked trunk 25m tall Bracket Fungus,Ash Tree.Shaggy Bracket. Choosing the right replacement tree species depends on the surrounding plant community. A foliar disease primarily affects the foliage (or leaves) of the tree. Ash psyllid - small insects on tree leaves, resulting in curling leaves. Ash leaf cone roller - caterpillar/moth like insect that rolls tree leaves. Symptoms of a foliar disease include spotting, wilting and premature dropping of the leaves. Sooty mold looks a lot like the name implies. Common diseases of ash trees are ash yellows, verticillium wilt, and ash anthracnose.The most serious threat however is the emerald ash borer (Agrilus planipennis), common acronym: EAB.This beetle from Asia was discovered in Michigan in 2002. .