Use a pot? All of mine are in large sunken containers for this reason, they behave that way.

Won't the roots escape out the drainage holes?

I find it frustrating that so many nurseries don't give an adequate warning about the characteristics of the plant. About all I read on some passion vines is "vigorous" and I don't know if that is a warning about suckering or if it just means the plant grows quickly....

Incarnata, caerulea, foetidas and Incense (and related hybrids) will sucker. I've never had a problem with this, as they're easily mowed down. Interestingly enough, I've never seen my Amethyst or Lady Margaret sucker, even though their parent plants are known for doing so.

There is a chance the plant will escape it's 18 gallon prison, but I used a small drill bit, and preforated very few drainage holes in the very bottom. I'll second that my Amethyst is very well behaved, but it's only 2 years old.
Any time you see "vigorious" or "fast grower" remind yourself that nurserys are in the business to sell plants, and won't put "completely invasive, plant in concrete confinement" on a label, so if it's "fast growing" decide how much pruning/weeding you want to do of plant later.

Thank you for the help. Today I kill an Incense.....and search the Internet for a suitable replacement...