I'm having a similar problem with Petite Faucon.

All my clematis are flopping this year. I rigged up some supposedly sturdy netting all around the perimeter of my yard, which was fine until all this rain we've been having added a few hundred pounds to the vines. Everything is sagging - it's scary, really. I'm waiting for the whole garden to collapse LOL
I'll be going to the co-op to buy some cattle fencing - that should do the trick.
Judith

Yes, I was thinking I need to surround it with wire fencing. I have tried more cosmetic approaches, but the end result wasn't cosmetic.

If C. recta is grown in absolute full sun in soil that isn't too rich, it tends to stand upright on its own. That being said, it never seems to happen that one's soil type is exactly right. An obelisk that you can tie it to is a solution I've tried.

Have you tried peony "grow-thru" rings? I used these on C. recta in my old garden and found they worked very well. They need to be in place before the clematis puts on much height so that the stems can grow through the support properly (the same method used with emerging peonies) but the exact placement can be adjusted after the clematis starts to grow. I found if the ring was approx. 18-24" off the ground, it provided enough support to keep the clematis nicely contained, yet allowed the top to fountain gracefully. Like the peonies, the plant never looked obviously "caged".

Here is a link that might be useful: grow-thru rings

Thank you so much for the peony hoop idea. I have some of those, though I don't think they have the grid, so I will buy that kind. I had wondered if something like that might work. The obelisk didn't look good past bloom time, when the stems drooped. It is in full sun at bloom time, but not early in the spring, so it probably is lanky. I believe it is too big to move, though maybe I could try to divide it in the spring.

Good idea, I think I'll whack my recta after it finishes blooming and try it.

Petite Faucon is too big for that idea though...