The National Gardening Association has found that, among vegetable gardeners, tomatoes are their favorite plant to grow. One in three Americans have a vegetable garden, and 9 out of 10 of those gardens have tomatoes in them. Tomatoes range in size from gigantic beefsteak tomatoes that can weigh up to a half-pound, to the smallest cherry tomato about the size of a marble. You can grow heavy-yielding hybrids or open-pollinated heirloom varieties in...