I was a warm zone SAC grower (zone 7) and it did seed all over. It was a prolific grower, would be cut to the ground each year, and the next season it would throw out 30' of regrowth.

The biggest problem you'll have in a colder zone is it will potentially (100% guarantee it will) flop over onto your neighbor's side of the fence and you'll run the risk of having it hacked down.

There are quite a few threads on Sweet Autumn Clematis on the Clematis forum, as well as the Vines Forum - check them out. And from what I can remember, while cooler zone growers marvel at its luxuriant growth, they don't find it to be freely self-seeding.

I'm in the NW suburbs of Chicago and had a sweet autumn clematis for many years in the yard. I never saw any "volunteers" and never heard that it would spread. It does get much bigger than other clematis, but it was fine on a trellis. It never got out of hand,came back great every year and never had bugs. On the other hand, it does attract bees. I never noticed the nice odor it was supposed to have and was a little disappointed with that.

I did cut it almost to the ground every year.

Attracts bees, eh? I already have a problem with wasps and carpenter bees - bleah. As a general rule bees are welcome but I certainly don't need an invasion of them :)

The fence is about 7 feet tall and there is lots of room for the clem to go horizontal if I can train it that way. I'll have a talk with my neighbor and see what she says. She's very reserved and polite though and probably wouldn't tell me she hates the idea even if she does.

Barbara

I also live in the Chicago area, by the lake, which gives us slightly longer springs and summers than most in the area. I'm pretty much zone 6. Sweet autumn clem does indeed self-seed for me, sometimes into the lawn. I just usually dig those up and give them away. If you let SWA clamber over a small tree or bush, it can be overwhelming to the host plant.

Still, I don't consider it to be an "invasive" vine, merely enthusiastic. And I've never noticed that I have a plague of bees, but then again I like bees.

I'm in the Des Moines area, and yes my sweet autumn reseeds--but I've only counted 5-6 volunteers in that many years. Climbing over the fence sounds like the biggest risk for you, from what you say about your neighbor, since this vine can grow 15-20 feet long/tall. However, I enjoy it so much, I think it's worth having. Cut it back hard every year, and you'll be able to keep it in control.

How does it take to pruning during the growing season? I could always try to keep it under control that way.

I'm vacillating between the sweet autumn clematis and Polish Spirit, which is also supposed to be quite vigorous, though not invasive.

Hmmmm...

A friend of mine who lives just north of the river has one growing and she gets volunteers (from seed) all over her yard....

I potted a couple up to bring home (have the room for them to go nuts)....

Thanks for the input, Kat. I have a postage stamp sized backyard so the fewer invasives, the better. Although if they're easy to identify and uproot, that's not such a problem.

BTW, are you thinking of hosting an exchange get together this spring? I have travel plans for May so I'm trying to think far, far ahead.