I planted a garden with tomato plants, green peppers, lettuce, carrots, onions, potatoes, cucumbers, watermelons and pumpkins. The tomatoes, lettuce, cucumbers and potatoes produced well. I only got 2 green peppers from 9 plants. The watermelon plant bloomed several times but no watermelon. I had 6 healthy pumpkin vines that grew and bloomed, but only one pumpkin. The onions aren't much bigger than what they were when I planted them. Any idea as to why the plants all grew and look extremely healthy, but no produce? I have never had this happen before and I am puzzled.