Great Shade Trees

Great Shade Trees

Part of Ep. 1002 Spring Games

Discover the many shade tree choices with Dr. Laura Jull, the Woody Ornamental Extension Specialist for UW Madison.

Premiere date: May 22, 2002

TRANSCRIPT+
Wisc Gardener Transcript: 

Shelley:
Would you like to make your home more energy efficient in the summer? Here's a real simple solution, plant a shade tree. We're at the UW-Madison Arboretum, in the Longenecker gardens. And I'm with Dr. Laura Jull. Laura is the Woody Ornamental Extension Specialist for UW-Madison. Laura, let's start out with this one. This is a Kentucky Coffee Tree, and I've always wondered where it got its name.

Laura:
Kentucky Coffee Tree gets its name because the female tree-- it has separate sexes-- The female that produces the fruit has these seeds inside of the pod that the Native Americans used to roast and grind and use as a coffee substitute. But I don't recommend homeowners do that, because they do have some poisonous alkaloids in the seeds.

Shelley:
So, if we don't know how to do it, it's not something to play with.

Laura:
No.

Shelley:
And I know that those pods can be unsightly in the fall, too.

Laura:
Yeah, they can. I actually don't think they're that unsightly. But if you choose not to have those seed pods on the tree, you can plant a male cultivar. And that's, of course, seedless. And one of the male cultivars that's now in production is called Espresso.

Shelley:
A perfect name for a coffee tree. So, we can choose either way, if we want the pods or not, then. Pick a male with no pods or a female with.

Laura:
Right. Kentucky Coffee Tree has some very outstanding qualities to it. First of all, the leaves are gigantic on this tree. It has very large leaves.

Shelley:
This is one leaf?

Laura:
Yes, this is one whole leaf. And it does provide some dappled shade. It has these very small leaflets that will allow sunlight in, so you can grow grass underneath.

Shelley:
And for a lot of shade trees, I don't think of a lot of lawn under it, so this is a good choice for that.

Laura:
Correct.

Shelley:
Now, I can also see the bark. First of all, I just can't stop touching it. This is just incredible, the winter interest must be fantastic.

Laura:
Yeah, it has this kind of fish-scale look to the bark. And it does have yellow fall color in the fall.

Shelley:
Now, it has a few other merits. It's a fairly low maintenance for us.

Laura:
And very insect and disease resistant.

Shelley:
Excellent, that's a good choice, then. Well, this is a tree that's not used a lot when we talk about shade trees, either. Now the Silver Linden, you said is another one that is a good choice that we don't normally think of. And I like the shape of this one.

Laura:
It has a very nice, formal, pyramid look to it when they're young. And unlike the Kentucky Coffee Tree, this one is not native to Wisconsin.

Shelley:
Okay.

Laura:
But just like most of the shade trees that we're going to talk about today, they do get roughly about 50 to 60 feet in height, so you want to make sure you don't plant them under or near power lines.

Shelley:
Always good thinking ahead of time, because when we plant them small we just don't see that sometimes.

Laura:
Right.

Shelley:
And what about grass underneath this one? It looks a little more dense to me.

Laura:
Probably not recommended. Most of the larger-leafed trees, trees with larger leaves, don't grow grass underneath the trees as well. This is called Silver Linden, because on the undersides of the leaves, they do have kind of a silver color to them.

Shelley:
Oh, look at that. It's beautiful.

Laura:
It really is ornamental when the winds blows through it. It has this sort of dappled effect to the leaf.

Shelley:
Now, I'm seeing-- Are these flowers or seed pods here? What is this?

Laura:
This is actually the fruit, on Lindens in general. They have this bract-like fruit, or a modified leaf. And then, the fruit is at the base of it. What's really ornamental, is in the summer when it flowers. The flowers on all Lindens, including our native Basswood, they're fragrant and yellow in summer.

Shelley:
Wonderful. Okay, what about fall color then in the fall?

Laura:
Fall color on this one is yellow.

Shelley:
Okay, so its got a lot of interest for us. What about maintenance, again? Is this a low maintenance tree?

Laura:
Yes, Silver Linden is generally lower maintenance. It tends to be one of the more drought tolerant Lindens. And also, it is more resistant to Japanese Beetle, which is now becoming an issue in Southeastern Wisconsin.

Shelley:
A big issue, okay. That's a good reason to plant it. Well, what about something with more brilliant fall color. A maple, or something?

Laura:
Yeah, one of my favorite maples is Freemen Maple. And Freemen Maple is actually a native hybrid, a natural hybrid, between our native Red Maple and our native Silver Maple.

Shelley:
Now, I had a Silver Maple for a while, and after every storm, I just decided to call it a junk tree. There were always broken branches all over.

Laura:
Yeah, well, Freemen Maple gets its good characteristics from one of its parents, the Silver Maple, and then it's more tolerant to higher pH. But like its other parent, the Red Maple, it has very nice fall color. So, it kind of combines both characteristics of the trees to get an outstanding hybrid.

Shelley:
And we don't get the weak branches either, then.

Laura:
Not only that, Freemen Maple is more tolerant to higher pH soils than our native Red Maple. And the fall color can range from yellow, orange, to red depending on the selection.

Shelley:
And do you have a preferred selection?

Laura:
Probably one of my favorites is the Autumn Blaze, and that has flaming red fall colors. It's very, very nice.

Shelley:
It would look nice next to the Linden.

Laura:
It sure would.

Shelley:
Let's look at one last group, the oaks, because I think people aren't planting oaks much anymore because we're all afraid of oak wilt.

Laura:
Yeah. And oak wilt is a very serious, devastating disease that affects oak trees. Now, there's two different types of oaks, there's the Red Oak group and the White Oak group of our native oaks. And Bur Oak is in the White Oak group. And the White Oak group is characterized by having leaves with rounded lobes. Now, Bur Oak is an outstanding native prairie oak. It's very drought tolerant, and again, very high pH tolerant. It does have this relatively slow growth rate, but it develops into a marvelous, majestic tree in the landscape.

Shelley:
And this is a group, the White Oaks are, what would you say, more tolerant to oak wilt?

Laura:
They can get Oak Wilt, but generally, they're more tolerant to it and can be treated for the disease if they do get it.

Shelley:
So, it's still worth planting, like you say, because they're just so beautiful.

Laura:
Yeah, I love oak trees. Not only do they have a nice look in the landscape, but they also provide a food source for our animals.

Shelley:
These are some great choices, then. Thanks, Laura.

Laura:
Thank you!

Shelley:
To check out some more shade tree choices, come to the UW-Madison Arboretum, the Longenecker gardens.

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