I plant all of mine in the ground, but I think three or four plants in a 12-inch hanging basket would look fantastic in a fairly short time. The best trailing varieties for hanging baskets won't be hardy in your zone, so you'll want them to put on the best possible display the first year. I think the fancy hanging fuchsia baskets for sale in nurseries have three or four plants in them. As for food, I don't know. I never use it. One of my neighbors uses Osmocote pellets in her containers and they always look great.
