Sometimes they are and sometimes they aren't. My mother got a seedling from someone years ago and in due time it threw seeds and made babies. I liked it and so did my daughter so we each dug one and planted it. Mine grew and has bloomed for years and it seems to make seed but I've never seen a single seedling. My daughter's on the other hand has seeded heavily and mother's continues to seed. So if it were me, I wait to see. Maybe someone on here will know more about it.

So far ours has not been a problem. I am not big into flowers, but I kinda like this one.

I got mine a few years ago at a Spring Fling and I think it is now in it's 4th year. It is a big plant but I haven't seen seedlings anywhere. On the other side of the coin, I see it growing over lots of bushes in Grove near Hiway 59 and it seems to be trying to take over.

My autumn blooming clematis is very invasive. It is too late to get rid of it now. It climbs over shrubs and I have to pull it out every year not successfully but enough so the shrubs haven't died. The savior of the shrubs is blister beetles that eat all the leaves off most years late in the summer. I will always have it. Years ago someone gave my friend in Joplin a clematis. He thought it would be a large flowered one but it is the autumn blooming one. We fight it but it is in the chain link fence and among azaleas where round up is not possible. I do have an autumn blooming clematis in my front yard that has not been a problem. There may be more than one kind. We went on a short train ride in Pittsburg Kansas a couple of years ago - Little Balkan Days. Autumn blooming clematis was all over the trees everywhere along the side of the railroad tracks.

What I think is odd is that both my daughter's reseeding one and my non-reseeding one came from my mother's plant which itself was a seedling from someone else's vine.

I think some areas are better suited to a plant than others. That is why I can't grow marigolds and the most basic gardeners can! That's my story and I am stickin' to it.

I do grow a lot of thug plants. I wish I could rid my gardens of the morning glory...wild and otherwise and the bind weed. It'll never happen.

Dorothy, I wonder if there are male and female plants?

And there may also be something about having surrounding plants of it in the woods, or city, to cross pollinate with.

Many plants are self-infertile. So, if no others within a mile or two, no seeds.

Carole and dbarron, Good thoughts. I don't know. My parents and I live without close neighbors and my daughter lives in town. It's a puzzle.

Thanks everyone. I'm just going to keep it! I love it!!!

Sorie, I had it here for a few years and loved it. It bloomed beautifully, never reseeded (but I had it in wicked red clay soil where seeds usually rot in winter before they get a chance to sprout the following spring), and only occasionally had all the leaves stripped off of it by blister beetles. I lost it in a drought year when we had around 24-26" of rain over the course of the year, but precious little of it in the summer months. I expect you'll likely have no problem getting enough rainfall for it there in the fabled Green Country of northeastern Oklahoma.

I happen to personally love invasive plants, though there is little that seems to really be invasive here at our place. If our hot, dry summers don't kill an invasive type of plant, then our wet winters with slow-draining soil usually will. So, when I find something that truly is invasive and survives both our hottest, driest summers and our coldest, wettest winters, I plant lots and lots of that invasive plant. Here at our place I just think of those plants as "survivors".

Dawn