It's invasive in places with summer water. I'm in Sonoma County and have three of them, and they seed like crazy. I use drip irrigation so it is primarily a matter of clearing the seedlings away from the drip holes near the plants. Interestingly, the birds don't seem to have dispersed the seeds at all, for I have never found seedlings anywhere else than around the base of the three vines I have (two on arbors, one on the side of the house). So I don't worry about it being invasive in the area since on our 33 acres it has made zero impact away from its own locations. I would not plant it if you use overhead water, as you'll have a much bigger seedling problem that way.

It's a fabulous plant for fall interest and the flowers, which are completely insignificant to us attract pollinators profusely - both honeybees and a wide variety of native pollinators. It looks pretty hellish in winter, though, and is late to leaf out in spring (just beginning).

Thanks very much for your clear information- it is very good news for my garden since I plant for bees and other pollinators and don't have an overhead watering system. Min

You're welcome! My biggest gripe with it is that it is so late to leaf out, but so is the Vitis 'Roger's Red' on my other trellises...
Sara

I can wait for the leaves- so much other garden interest in spring. And they are worth it when they do leaf out. Min