If I didn't sow any seeds, I know I would have a large mountain of volunteer nasturtiums and pumpkin plants, sure to overtake the other plots around me. By the way, know this is not a way to become popular and well-liked in a community garden.
In the center my plot would sprout a humongous tower of nasturtiums, flowers waving gaily at everyone. On the sides would be the volunteer pumpkins.
Here are two that grew over this summer, despite the wet and cold weather we endured that we euphemistically called 'summer'.