I live in zone 5. A friend of mine planted this next to her house along with climbing roses and Autumn Clematis years ago. BAD idea! It has grown underneath the foundation of her house and comes back vigorously every year despite her doing her best to uproot it. This vine indeed thrives very well in zone 5 and def will become invasive. It will take time, but it will "Creep Out" and show up everywhere lol. The lady across the street has two trained around old clothes line poles to make "trees". They are beautiful. People stop all the time to ask her what kind of trees those are. She regularly mows around them and does not have an issue with them getting to full growth in the grass around the original plantings. We do tend to have unseasonably warm winters at times. Perhaps that contributes, but be careful with this one! You've been warned! lol

Perhaps Cynanchum laeve. Here is a link that might be useful: Cynanchum laeve

One of my Star of Siam seed pods has rotted. I'm not sure what happened but after it was cracked I pried it open and the second I saw white wormies (kind of look like maggots) I freaked out and tossed the whole thing in the trash! I'm still freaked out now. I have another seed pod growing on there but I am not sure how to ensure that it doesn't happen again! That was sooo GROSS! I need to get the image out of my head or I'll toss my dinner!

w/o a botanical latin name.. its hard to look it up for you ... perhaps your blue version is sterile .... as the breeders move from the plain old color [red???] .. to the more exotic.. it is very common for the end effect to be that the plant is sterile .... that is presuming that your z9 trumpet vine.. is the same plant i know as trumpet vine.. here in z5 MI ... common names can be very problematic ... if you dont have the name.. a pic might get you an ID ... ken Here is a link that might be useful: how to post pix