Yes, I grew butternut squash in large pots (about 2ft across top) last year and I put two plants in each. In one of my pots a courgette crept in (I obviously couldn't tell the difference as the leaves are similar when they are small plants - or similar to me a bit of an 'infants' class gardener')! I got about 7 squash from four plants, so not bad. This year I'm going to try just one plant in the centre of each pot (and get more big pots) instead of the one at each rim that I did last year. See if I get more. But the squash was delicious.