Ask NRRI

"What are the possibilities for using Ash wood after the Ash Borer infestation?"

NRRI Scientist
Brian Brashaw answers:

Ash trees are extremely vulnerable to the Emerald Ash Borer (EAB), an insect that kills ash trees over several growing seasons. The initial areas of infestation were in Michigan, and have expanded into 16 states in the upper midwest and northeast United States. EAB has been identified in Minnesota, with infestations in the Twin Cities and also in Winona and Houston Counties. An excellent source of information on EAB can be found at www.emeraldashborer.info.

In Minnesota, we have essentially two classifications of ash: black ash and white ash. Black ash (Fraxinus nigra) has heartwood that is a darker brown than that of American white ash; the sapwood is light–colored or nearly white. The wood of the black ash group is lighter (basic specific gravity of 0.45 to 0.48) than that of the white ash group (basic specific gravity greater than 0.50).

Important species of the white ash group are American white ash (Fraxinus americana) and green ash (F. pennsylvanica).The heartwood of the white ash group is brown, and the sapwood is light-colored or nearly white. Both of these species can be used for many applications where oak or maple is used, including decorative veneer, cabinets, millwork, paneling, flooring and furniture and lumber for pallets. Further, white ash is desired for many applications that require wood that is heavy, strong, hard, and stiff, with a high resistance to shock. American white ash is used principally for non–striking tool handles, oars, baseball bats, and other sporting and athletic goods.

A final use of ash is for solid biofuels. It can be used for firewood or as a feedstock for wood pellets. However, it is essential that hardwood firewood not be moved more than 50 miles from its source, since the movement of firewood is a primary means of EAB movement. Producers should understand regulations established for firewood by the Minnesota Department of Agriculture and the USDA Animal and Plant Health Inspection Service (APHIS). Our NRRI staff has been involved with the development of thermal heating procedures to ensure that EAB larvae is killed in firewood.