Trees to Plant Instead of Ash

Trees to Plant Instead of Ash

Part of Ep. 1602 The Good, the Bad and the Ugly

Extension woody ornamental specialist Dr. Laura Jull discusses alternatives to ash trees. The Emerald ash borer has been devastating ash trees throughout the Midwest. Planting alternative species is a great way to prevent a mass destruction by an insect pest. Alternative trees include Baldcypress, Miyabe Maple, Kentucky Coffeetree, Triumph elm, Frontier elm, Chinkapin Oak.

Premiere date: May 14, 2008

TRANSCRIPT+
Wisc Gardener Transcript: 

Shelley:
Ash trees are lovely in the landscape. Unfortunately, there's an insect that creates havoc with them. We're at the UW-Madison Arboretum with Dr. Laura Jull woody ornamental Extension specialist to talk about planting something other than ash trees. Why are the ash trees suddenly in such danger? 

Laura:
There's an insect called emerald ash borer. And this is an insect that is not native. It has been devastating ash trees throughout the Midwest Michigan, Ohio, Indiana, Illinois, Canada. It's moving this way, unfortunately.

Shelley:
So it's inevitable.

Laura:
Unfortunately, probably. And it's an insect that bores inside the trees and actually kills them. There's not a whole heck of a lot we can do about it. We can use preventative systemic insecticides in the tree. However, if the tree is located in a target zone where there's an infestation of emerald ash borer all ash trees regardless of whether they were treated or not within a half-mile radius will be removed.

Shelley:
If you've got one in your landscape or cityscape it's going to come down if it's part of that infection.

Laura:
Unfortunately, yes.

Shelley:
It also leads to the point that we should never plant a mono-culture, anyhow. If we plant all of one thing who knows what insect or disease is going to wipe them out.

Laura:
The same thing happened with the American Elm and Dutch Elm Disease back in the '50s and '60s. It just devastated our urban forests. Many trees were cut down from the disease. And you know, alternative species is a great way to prevent a mass destruction by an insect pest. One of the trees we have here is Baldcypress. And this is one of my favorite trees.

Shelley:
And they're gorgeous, look at that.

Laura:
It has beautiful, soft, feathery foliage that will turn a darker green in summer. And in the fall, the foliage turns a nice russet brown color and drops to the ground. You really don't need to rake these leaves up.

Shelley:
Oh, good! 

Laura:
It has a very nice branch pattern as well as beautiful trunk pattern.

Shelley:
Look at the bark on it, and it's hardy.

Laura:
If you get it from a northern seed source, most nursery and garden centers around here would be growing a northern source.

Shelley:
This one is about 50 years old but even a young one is going to have some interest in the landscape. Okay, I'll plant one. What else? 

Laura:
Some other things we could plant is a maple called Miyabe Maple. And Miyabe Maple is a very urban tolerant tree.

Shelley:
Good for the cityscape, as well.

Laura:
It's not invasive, unlike Norway Maple and it has bright yellow fall color. There is a selection called "State Street" of Miyabe Maple. It has nothing to do with State Street in Madison, but it was a selection out of the Morten Arboretum. It's a single stem form and a very nice tree.

Shelley:
So, again, we can plant shade trees. If anything, we should try to plant one of each of these and then have variety in our landscape.
Laura:
Diversity is key to help prevent a massive, widespread infestation of an insect devastating our urban forests. Some other alternatives are the Kentucky Coffeetree.

Shelley:
Oh, I like that tree.

Laura:
It's a native tree. It's a very nice tree. It has beautiful blue-green foliage, interesting bark. And females do produce a pod that hangs from the tree. Some people don't like that.

Shelley:
I love them! 

Laura:
I think they’re interesting. But if you don't want those pods there's a male selection called Espresso. The Espresso Kentucky Coffeetree has no fruit. That's another one.

Shelley:
And I love the bark of that. The huge leaves are something unusual. People don't see these things in the landscape.

Laura:
Yes, exactly. Another with regard to elms. There are many hybrid elms that are out there. There are some that are American Elm hybrids. Unfortunately, those are a little bit hard to find in the nursery, greenhouse or garden center trade. One of the selections that doesn't have American Elm in it that I particularly like is called Triumph.

Shelley:
That means we don't have to worry about Dutch Elm.

Laura:
It's supposed to be resistant. But again, resistant doesn't mean immune. But it's supposed to be resistant. I've seen it as very nice, dark green, glossy leaves. So the Triumph elm is a nice one. Another nice elm is called Frontier. That one's a little bit smaller, about 35-40 ft. The nice thing about it, is it has burgundy leaves.

Shelley:
Lovely, and nice in a smaller landscape, too. Okay, are we forgetting anything?  Oaks, what about oaks? 

Laura:
Chinkapin Oak is a native oak to south central Wisconsin. Not a lot of people know about this oak. It's a beautiful oak. It's in the White Oak group, so it's less susceptible to oak wilt though it can get it, as any oak can get it. It's naturally tolerant to limestone soils.

Shelley:
Perfect.

Laura:
It tolerates high pH already. It has a smaller leaf, a scalloped shaped leaf. A very beautiful tree. Interesting looking bark, as well.

Shelley:
So lots of choices. Plant a mix of all of these. We've talked about some of them being susceptible to disease. Any tree that is under stress is more susceptible. Take good care of your trees with mulch and water.

Laura:
Water, water, water, that's the most important thing. Especially during a summer drought.

Shelley:
Okay, thank you Laura.

EPISODE SEGMENTS+
EPISODE RESOURCES+

Buy DVD »

Funding for The Wisconsin Gardener is provided, in part, by The Wisconsin Master Gardener Association.