As I noted a few posts back, this summer marks the 10th anniversary of the discovery of emerald ash borer (EAB) in southeast Michigan. While a lot of progress has been made on many fronts in the battle against EAB, the outlook for ash trees in North America still looks bleak for the foreseeable future. Ash trees, both green and white ash, were popular choices as street and landscape trees throughout the Midwest and elsewhere. In Michigan ashes comprised up to 30% of the overall tree cover in some communities. Like chestnut blight and Dutch elm disease, EAB provides a cautionary tale of the destructive potential of invasive pests. As global trade continues to increase (and the potential for exotic pest movement along with it), the most practical defense in the near term is to spread the risk and increase species diversity. In spring 2003 Bob Schutzki and I installed an ash alternative species demonstration at the MSU Tollgate Extension Center in Novi, MI, near the epicenter of the EAB infestation. As we near the completion of the 10th growing season of the planting we can take stock of some of the better selections.
Dana (R) and Aniko assess the lindens
Hophornbeam Ostrya virginiana
Hardy rubber tree Eucomia ulmoides
Northern pine oak Quercus ellipsoidalis (R) can maintain good leaf color even when soil pH turns Q. palustris (L) chlorotic.
American Sentry linden Tilia americana ‘McKSentry’
Baumannii horsechestnut Aesculus hippocastanum ‘Baumannii’
State street maple Acer miyabei ‘Morton’
Thanks to our partners!