What is it? The "heirloom" in heirloom tomatoes refers to the fact that many of the seeds have been passed down through generations of families. Cultivated for any number of characteristics, heirloom tomatoes come in endless shapes, sizes and colors. Another distinct characteristic of these boutique-like tomatoes is their open pollination. According to Wikipedia, this form of pollination is the basis of the popular "birds and bees" story we all hear around puberty - basically, wind, birds, bees or other natural forms of pollination help to propagate various types of heirloom tomatoes. Lucky for us, these usually small-batch crops of tomatoes are only picked when ripe and in season, which is why they taste so much better than commercially grown tomatoes, which are picked early and artificially ripened.
What is it used for? Most heirloom tomatoes found in grocery stores are best eaten with very simple preparations. Salads work best to highlight their superior flavor and beautiful shapes and colors, although their versatility extends to anything where a regular tomato can be used. Easy and delicious: Just drizzle raw tomato slices with a light vinaigrette or olive oil to enhance the already ripened flavors.
Where can you buy it in Houston? Central Market is almost a sure bet - you can get them almost any time of year, but they're not always locally grown. These two traveled all the way from Canada. Farmer's Markets (in the summer) are also great places to scout for the ripe, multicolored tomatoes.
Recipe: Heirloom Tomato Panzanella - Courtesy of Food Network