Green ash is abundant in Nebraska’s native woodlands and was commonly planted throughout the state after Dutch elm disease. However, the introduction of emerald ash borer has left the species in peril. We no longer recommend planting any native ash trees in Nebraska.
The species is distinguishable by its opposite set leaves (and buds) and a smooth gray bark when young that matures to a thick and fissured bark with a distinctive diamond pattern with age. Positive attributes of the species include its tolerance of both wet and dry soils, resistance to climatic extremes, fast growth rate and reliable yellow fall color. Negative attributes include the frequent damage caused by insects (especially lilac borer) and the fact that it has been overplanted in many communities.
The Manchurian ash (non-native) is believed to be tolerant to the emerald ash borer. Tree enthusiasts should be tempted to give it a try.
Emerald ash borer was introduced into Michigan around 2002. It is believed to have traveled from Asia in contaminated lumber. It is widely accepted that the insect has killed tens of millions in ash trees in the US. Nebraska detected EAB in Pulaski Park in Omaha in June of 2016 (see the photo below).