I accidentally grew a pumpkin!

After multiple tries to grow tomato, pepper, onion, and zucchini, I had given up. I could get nothing to grow...clearly, I do not have a green thumb! Then, one day, a large green vine started growing out of my compost bin. It got longer and longer and bigger and bigger. At first I thought it was a zucchini plant. But, it turned out to be pumpkin. We had to leave for a month just as the pumpkin was forming. I had no idea what to expect upon our return. When we got back, the vine had withered and what was left was a large green pumpkin. It has since turned (mostly) orange and is now on our dining room table. Apparently, my former failures were due to a soil problem!