Gardening

Composting with those leaves won't hurt anything, as it'll come back to your garden no matter what. What happens is that your squash plant loses the ability to fight it off as it ages and winds down it's life cycle. Dehydration can stress it so that it gets infected too. But it doesn't matter what you do, towards fall it'll kill off your plant, but just be aware that the plant was already done anyway. The only time it's an issue is if your plant is too weak to stay healthy and then it will succumb too early, but the solution to that is obviously just to raise a healthy, hydrated, fed plant - not worry about your compost.