I've been contemplating ripping my pumpkin vine out and putting in a cover crop. It has yet to set any pumpkins. All of the female flowers have fallen off due to stress (vine borers and mildew). But every time I think about it, I look at the flowers. My bees are so happy with the pumpkin blossoms. Plus they help to fertilize my summer squash.
So instead of ripping them up, today I just sowed the cover crop over the area. When it germinates I might pull the pumpkins up, or I might wait until the cover crop is a little bigger. The pumpkin vine is not in its planting spot anyway. The vine took off over the fence into the perennial border and the old leaves have all died off, so that patch of ground is bare - but not for long.
I tend to cover crop my garden sporadically. If the area is bare and I don't plan on planting anything for the fall, I'll put something in - provided I have seeds on hand. This year I remembered to order seed so I'm all set. In the past I've used vetch and rye, both are hardy in my climate over the winter. But rye is allelopathic (puts out chemicals the inhibit growth of other plants). Sadly it is the only winter hardy grain here. But UMass Extension has done some research on production, and even though oats die off over the winter it still makes the best pairing with vetch. So this year it is oats and vetch.