Green Ash

It takes a while for things to get a grip in my sandy hot yard (zone 5, NH) but this just never took off. It's been 10 years, and it's g...Read Morerown about 4 inches. Time to pull it out and replace it with something hardier.

It has been a fast growing, about 2 feet/year shade tree, very adaptable, and reliable for decades. It and Honeylocust have been the most...Read More commonly planted shade trees for the last few decades in the Midwest and East. They have been able to withstand the hard construction soils of new developments. The cultivars of Summit, Patmore, and Marshall's Seedless have been the most commonly planted. It is a good tree, but just average in appearance. Technically, the Green Ash is the hairless natural variety while the Red Ash is the variety with hairy twigs and some hair under the leaves. Normally this species develops a good yellow fall color.

Recently, the Emerald Ash Borer from China is devastating this species more than any other ash in MI, Oh, IL, IN, WI, and moving east into PA and the Mid-Atlantic. Lots of dead trees in landscapes, fields, and forest edges. Hopefully, a number of resistant survivors will be found.

Green ash is one of the most commonly planted ash species thought there are several other species of ashes that are a bit difficult to te...Read Morell apart - thus the very low numbers of reported 'have this species'. Blue ash are hard to find in the nursery trade because of their large amount of seeds produced by female trees while black ash are more of a weedy species - more leggy in appearance.

Diseases - free? No way - Green ash regularly get infected by a nonnative species of ash bug (Homoptera family) which hits every year, and when the tree is stressed, causes most of the leaves to be shed, creating new ones in mid summer. There's a gall type that hits the flower buds, leaving it brown and hanging on the branches for between one and maybe 5 years (I guess) and leaves tannin stains (brownish) on concretes and asphalts.

Green ash is a favoured tree in urban landscapes because of its hardiness, adaptability and resistance to pests and diseases. It's consi...Read Moredered a good "solar friendly" tree for energy conservation. It gives moderately dense shade in summer due to its compound leaves, and its open branch structure allows sunlight to get through in the winter. It is often the last tree to put forth leaves in spring and among the first to drop them in autumn.

Because of its good qualities, green ash is often overplanted. A new and growing threat to these trees is a non-native insect called the emerald ash borer (Agrilus planipennis). It has killed millions of ash trees in Ohio, Michigan and Indiana. It is also present in southwestern Ontario.