Summer Blooming Trees & Shrubs

Summer Blooming Trees & Shrubs

Part of Ep. 704 The Summer Garden

Visit UW-Extension Woody Plant Specialist Dr. Laura Jull for a look at some of the trees and shrubs that bloom in the summer time.

Premiere date: Aug 28, 1999

TRANSCRIPT+
Wisc Gardener Transcript: 

Shelley:
You might expect to see colorful blooms like this in early spring when so many trees and shrubs are blooming, but this is the middle of summer. I'm with Dr. Laura Jull, Woody-Ornamental Specialist for the University of Wisconsin-Madison. And Laura, are there many choices if we want a tree and shrub that bloom in the summer time?

Laura:
Actually there is, Shelley. This is a wonderful selection. This is the smokebush.

Shelley:
Wonderful.

Laura:
Isn't it beautiful?

Shelley:
How tall is this?

Laura:
Smokebush gets approximately ten to 15 feet in height, with this kind of open wide spreading form.

Shelley:
It has a very airy look to it.

Laura:
Doesn't it, though? It's native to Europe and central China. And this is the cultivar called Nordine. And Nordine is a cold hardy cultivar. It's cold hardy to zone four.

Shelley:
So, a lot of us that can't grow some of the other kinds of smokebush could grow this one.

Laura:
Yes, absolutely. It's noted for a number of its ornamental features. First of all, the new leaves are kind of this purplish color, gradually fading to a purplish green color. And look at these outstanding flowers. Aren't these gorgeous?

Shelley:
They really look more like a seed head. This is the actual flower?

Laura:
Yes, it is. It's actually the hairs on the pedicel that have elongated, giving it this smoky or fuzzy look to it. It's absolutely stunning.

Shelley:
From a distance, it must look like this whole tree is filled with smoke.

Laura:
It does, actually. And they bloom from July to about mid-August.

Shelley:
So, it really is a middle summer bloomer.

Laura:
Absolutely. And then in the fall, it treats us to its outstanding fall color of orange to red.

Shelley:
So, we've got several seasons of interest in this.

Laura:
Absolutely.

Shelley:
You said it's cold hardy. What else do we need to know to plant something like this.

Laura:
Well, it prefers full sun to get the best display of flowers.

Shelley:
And an open spot, not crowded against your house, I assume.

Laura:
Absolutely. It will get quite large. It's also high-pH tolerant and drought tolerant, which is perfect for Wisconsin. There is one precaution. It is susceptible to verticillium wilt, which is a soil-borne fungus disease. It stays in the soil and attacks maples and some other plants. So, if you know you have verticillium wilt or have had plants that have died of vert wilt, you don't want to plant smokebush.

Shelley:
So maybe look at other options.

Laura:
Speaking of which, let's go look at some other options of summer flowering shrubs.

Shelley:
Great. Laura, I don't think of hydrangeas as being this massive.

Laura:
Yes, Shelley, this is about as tall as this hydrangea will get. It will only get about four feet in height. But look how wide spreading it is. You do need to make sure that you give it some room.

Shelley:
I need to plant mine in a larger spot, then. I think of my grandmother when I think of hyrdrangias. It's a real old- fashioned flower.

Laura:
The hydrangea your grandmother probably grew was the cultivar called Granda Flora. This actually a cultivar called Annabelle. And Annabelle is different from Granda Flora in that the flower heads are bigger.

Shelley:
They're beautiful. They're massive.

Laura:
They're absolutely gorgeous. They start out green, they gradually fade to a light green and then finally white. And then, in the fall, they turn brown.

Shelley:
So, they really hang on this plant a long time.

Laura:
A very long time.

Shelley:
In fact, some people leave them up for winter interest. I've seen people cut them and bring them indoors for dried flower arrangements.

Laura:
It makes an excellent dried flower.

Shelley:
What do we do to grow this. First of all, cold hardiness?

Laura:
It's cold hardy to Wisconsin. It actually prefers partial shade to shade, a moist, well-drained soil. It is not drought tolerant. But it is high pH tolerant, which is great for Wisconsin.

Shelley:
Any special care we have to give something like this.

Laura:
In terms of pruning, what we do is we actually cut this plant totally back to the ground and leave about four inches of stem material. The plant just suckers back beautifully in the spring.

Shelley:
Do this in February or March?

Laura:
In March.

Shelley:
And you're not leaving anything behind. You're really just cutting it back. Wow.

Laura:
And look how much has grown.

Shelley:
It also looks like maybe when the flower heads are out here it may need a little staking, especially after a heavy rain.

Laura:
The flower heads are a bit heavy and they do tend to flop over. Some people do stake it or put cages around it for support. But, it's an absolutely wonderful landscape plant for summer flowers.

Shelley:
And July/August. What a great thing to have looking out your window.

Laura:
Absolutely.

Shelley:
Let's take a look at one last one.

Laura:
Great.

Shelley:
Laura, this is beautiful. What is this?

Laura:
Isn't this gorgeous, Shelley? This is the bottlebrush buckeye. It actually only gets about eight feet in height, but it does look like it's a lot taller than that. It's deceiving, it's on a hill.

Shelley:
It's impressive this way.

Laura:
It's a wonderful, large suckering shrub for the landscape. And one of the main reasons why I like bottlebrush buckeye is these very long bottlebrush-like flowers. And actually, it's the stamins that have extended out, giving it the bottlebrush appearance.

Shelley:
So, these look like the old-fashioned brushes we used to clean out bottles.

Laura:
Absolutely.

Shelley:
And how long do these flowers last?

Laura:
They last a couple weeks and they bloom in July. So, again, this is a nice summer flowering shrub.

Shelley:
And you've also got nice, large, interesting looking leaves.

Laura:
They're beautiful. And actually, the bottlebrush buckeye is a relative of the horse chestnut and the Ohio buckeye, which do tend to get leaf blotch. But unlike those tree relatives, this does not get the blotch. It also doesn't produce fruit. So, you don't have the fruit litter like you do with the other ones.

Shelley:
And what about culture? Is it hardy?

Laura:
It's hardy to central Wisconsin zone four. It's a very low- maintenance shrub. It does better in full sun to partial shade. It is also high pH tolerant, which is excellent for Wisconsin.

Shelley:
Anything special I'd have to do to keep this thing happy?

Laura:
No, it's very low maintenance. In terms of pruning, you can remove the old flower clusters after they have faded simply by snapping them off. But you don't have to.

Shelley:
It looks to me like you really have to site this carefully.

Laura:
It does get quite big. But for summer flowers and also yellow fall color, it's a great landscape plant.

Shelley:
Just don't put it in there with your perennials.

Laura:
Right.

Shelley:
Thanks, Laura. If you'd like to learn what is blooming in the summer, come and visit the Arboretum gardens at the University of Wisconsin-Madison.

EPISODE SEGMENTS+

Download Podcast »

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