Does it matter if the collar slips down? The vines won't mind if the cane tops splay outwards. Personally I don't use plastic stakes. I use wood or bamboo and tie them with jute or sisal string. At the end of the season the string can go on the compost heap with the dead vines.

You could just tape strips of cardboard to use as collars. That seems like a vastly simpler solution. That being said, I agree that getting a plastic cane holder seems somewhat overkill. Just tie the stakes together at the top, or anchor them together with a hefty rubber band.

I do exactly the same as floral does......bind the stakes in a teepee formation with garden twine. It often lasts more than a single season but easy as pie to replace if it doesn't.

@tapla (mid-Michigan, USDA z5b-6a) The rope tie is an excellent Plan B, especially since I could choose decorative climbing rope whose color would enhance the display. P.S., I have six stakes in a teepee configuration, each with a different climbing vine. Some of those are Winter growers. Some of those are deciduous. Some like Black Eyed Susan Vine are year-round here in California. So I have constant floral interest and variety in each season.

Those stakes are hollow inside and the metal is thin. Get a pack of cheap sheet metal screws that are a half inch or so longer than the diameter of the stakes, drill a pilot hole in the stakes 6 to 8 inches from the top, and put a screw in. The screws will keep the stake holders up.

Rodney

@theforgottenone1013 (SE MI zone 5b/6a) Probably a good solution