Fraxinus pennsylvanica

Habitat

It is the most widely distributed of all the American ashes. Naturally a moist bottom land or stream bank tree, it is hardy to climatic extremes. The large seed crops provide food to many kinds of wildlife.

It is seriously threatened in some areas, particularly Michigan, by the emerald ash borer, a beetle introduced accidentally from Asia to which it has no natural resistance.

The spread of EAB was facilitated by the excessive use of Green Ash as an ornamental tree in the central US following the loss of American Elms in the 1950s-60s due to Dutch Elm Disease. That epidemic was the result of a similar overuse of elms in urban environments, leading to a monoculture that lacked any disease or pest resistance. Both American Elm and Green Ash were extremely popular for this purpose due to rapid growth and tolerance of urban pollution and road salt, so many housing developments in Michigan were lined from end to end with ashes, a result of which the beetles had an enormous food supply to boost their population. After the lesson of these twin disasters, urban planners in the region began a more sustainable planting program with a mixture of lindens, oaks, maples, and other trees to prevent a monoculture from existing again. EAB proved to be a far worse and potentially more serious threat than epidemics of the past such as chestnut blight and Dutch Elm Disease because those diseases spread at a slower rate, only affected one species, and did not kill the trees before they could attain reproductive maturity.

The Chicago Park Commission meanwhile has employed a quite successful program to salvage the ashes of the city's parks by regular spraying of their branches with pesticide to kill EAB eggs. This was done after discovering that merely felling infected trees did not stop the spread of the beetle since they merely proceeded to lay their eggs on living ashes.

Uses

Green Ash is one of the most widely planted ornamental trees throughout the United States and much of Canada but mostly Alberta, including in western areas where it is not native. Is also widely planted in Argentina. It is very popular due to its good form and resistance to disease. About 40% of boulevard trees in Edmonton, Alberta are Green Ash. It has several drawbacks as an urban tree, notably a relatively short lifespan compared to many trees , and more recently, the threat from the emerald ash borer. Advantages include its tolerance of urban conditions, ease of propagation, and its value for wildlife as a native species.

Green Ash wood is similar in properties to White Ash wood, and is marketed together as "white ash". The commercial supply is mostly in the South. It is very popular, used in making electric guitars because it can be somewhat lighter than white ash without sacrificing too much in tone. It has a bright sound with long sustain, plus the wood grain is aesthetically desirable to many guitar players. Gibson, Fender, Ibanez, Warwick, M2Guitars and many other luthiers use ash in the construction of their guitars.

Other names more rarely used include downy ash, swamp ash and water ash.