You can also graft tomatoes onto a potato plant for what's called a ketchup and fries plant. I don't particularly want to grow potatoes. They're cheap and fun full at the store and I would rather focus my energy on things that cost more money or are harder to find like interesting varieties of eggplants or fancy salad greens. That said the novelty of growing a plant that will produce both tomatoes and potatoes definitely has me intrigued and I think I'll give it a try this spring.