Many people in Portland, Oregon grow individual pumpkin plants even if they have no other vegetable plants.

Just prune the growing vines when they reach your limits; this may result in larger pumpkins anyway. A pumpkin should set on the first 5 feet of any vine. You can also maneuver the growing vines and use those big yard staples to keep them in place.

The main problem here is the leaves, that like most squash plants, mildew badly from August onward.

I've often seen people incorporate individual pumpkin plants into flower borders or foundation plantings. They just let the vines ramble across the lawn and mow around them. Looks really cool when the pumpkins are ripening! You can also plant pumpkins in large barrel planters. Just water and fertilize well. Then there is the time-honored method of tossing some pumpkin seeds on top of the compost pile--they love growing there!

I have a friend in WA who grows those miniature pumpkins down a rock wall(repurposed broken cement stacked up to make a dry wall) from one level of her yard to the next. It was a neat look. I was surprised to see even some "sugar" pumpkins (larger than cantaloupes) also able to sustain hanging on vines like that! I'm sure the bigger jack-o-lanterns might be a problem grown that way, but the smaller varieties hung on just fine!