If I had to name the plant I am most often asked to include in a garden design by a potential client, it would have to be wisteria (Wisteria floribunda, or Japanese wisteria). Sometimes, they don’t even know its name, but describe it in longing terms as “that wonderful plant that has long purple-y flowers that hang down.” I’m sure what they envision is something like this.
Or this.
Now don’t get me wrong – I think this is an extraordinarily beautiful plant in bloom. But I also believe that it only belongs in a garden IF (and this is a big “if”) the garden owner is prepared to support it properly, be prepared for a serious amount of maintenance work to keep it in check, and is OK with the fact that is potentially invasive – I saw it in masses when I visited Charleston in the spring in 2009, half-smothering live oaks, and even around here I see it weaving its way up tall trees on the edges of roadways.
Wisteria was introduced to the United States in 1830. It prefers full sun but established stands of it will live and even flower in partial shade. Here in DC, the most well-known stand of it in a public garden is probably at Dumbarton Oaks, where you can see it throughout the garden, although always carefully sited on structures that can support its weight.

Wisteria supported by an arbor at Dumbarton Oaks' Arbor Terrace (with the Fountain Terrace in the foreground).
So, take a close look at this photo from the Orangerie at Dumbarton, one of the first buildings you see on entering the grounds there.

The trunks of these wisteria vines are attached to the brick front of the Orangerie with wires and strong rubber ring supports.
Here’s the size the trunks can become over time. No wonder the gardeners here prune the wisteria three or four times during the growing season.
In the wild, wisteria trunks like this can attach to and ultimately strangle other trees. And if I find it wild in a garden I’m designing, I confess that I will do everything in my power to eliminate it (with the owner’s permission, of course). Still, its allure is strong enough that I have one client with a very shady garden who installed a wooden arbor just to support a volunteer, and this year (perhaps our mild winter helped), it has bloomed unusually well.
I have warned her that ultimately it may become too large and heavy for this support. But for now, she is happy. And this success inspired me to write this post. (For one last look at wisteria truly “gone wild,” although in a controlled environment, click here to see wisteria “tunnels” in Japan.)
What do you think? Do you love or hate this vine?