Black Ash Possible Substitute For Green Ash

With the potential of the Emerald Ash Borer coming westward to North Dakota and possibly devastating our Green Ash trees, homeowners ask for alternatives. This is a very difficult question to answer as I feel there is no tree equal to the hardiness and drought resistance possessed by Green Ash.

As an alternative deciduous tree to Green Ash I have suggested Hackberry, Linden, Bur Oak and Buckeye. In doing so, I must emphasize the limitations of each. After all, none of these trees, except Bur Oak, are native to western North Dakota. Another tree which deserves some consideration is Black Ash. I have found several plantings doing quite well in the Williston area, but in each instance the trees receive supplemental water.

Black Ash is a tree of northeastern North Dakota and grows best in bottom lands and other moist areas. Although it is not as cold hardy as Green Ash, it is considered a Zone 3 tree. This zone includes the southern parts of Saskatchewan and Manitoba along with the northern parts of North Dakota and Montana.

Black Ash will grow to be 30-50 feet in height. The crown width is usually about one-half of the tree’s height. I find the leaves and leaflets are a bit longer than those of Green Ash. The leaflets are dark green on the upper side and a lighter green on the bottom. I know of only one cultivated variety and that is named Fallgold. It was released by the Morden Research Centre of Manitoba.

It will do well when exposed to partial and full sun and should make a good shade tree. However, remember it will need additional water during our growing seasons.

If there is any deciduous tree substitute for Green Ash, it might be Common Hackberry. I say this because its cold hardiness is almost that of Green Ash and it does express some resistance to drought conditions, but like most other trees, it does better on moist, well-drained sites.

The leaves of Common Hackberry are bright green on the upper side and a paler color green on the bottom. As with Black and Green Ash, you can expect a yellow fall color. A Common Hackberry can grow 40-60 feet tall and have a crown width of 25-45 feet. As the tree ages I think its beauty is enhanced. It develops a bark that is grayish with distinct narrow ridges. Some describe the bark as having a stucco appearance.

A popular variety of Common Hackberry is Oahe. This was released by the USDA Research Center, Mandan. Another is Delta Hackberry which was developed in Manitoba.

Another tree deserving consideration is the American Linden, often referred to as Basswood. As it ages, its form becomes rounded which makes it a great shade tree. It has tolerance of our winters but it is not resistant to our often droughty summers but will do well in home yards with lawns which are well watered.

Suggesting a tree with no pest problems is not possible. Even our native trees such as Green Ash and Bur Oak can be harmed by an insect or disease. However, these two trees can be very forgiving when their needs for survival are ignored.