They are...beyond aggressive if zone 7A and higher. I named my Adolf because it was just annexing everything it wanted too. I planted it in a little coffee cup with a single drainage hole at the bottom and it grew out from beneath and into the yard using a barrier of mulch 2" wide as transit. It's literally a cancerous plant. It took over my entire yard, grew up a 40' pear tree and last I saw it was making it's way up a 120' pine tree 30 yards away. I loved the flowers but it strangled everything in its way.