Tomatoes are the berries of a plant belonging to the deadly nightshade family. It grows natively in the South American Andes and Mexico and was first used as a food in ancient Mexican cultures such as the Aztec. It was introduced to Europe by the Spanish after they colonised South America. It is now grown around the world.
Tomatoes have very large clusters of berries (fruit) and they often are too heavy for the weak stem, so that tomatoes are prone to collapse. In their natural habitat they sprawl over the ground, or grow up among other plants, using them for support.
Tomatoes are, strictly speaking, fruits, but we treat them as vegetables and eat them raw in salads and cooked, often in sauces.
In countries away from the tropics, tomatoes cannot survive cold conditions, and so we grow them as annuals, but in their native areas they grow over many years, and they are naturally perennials.
Native tomatoes were more yellow than red, very small and strongly ribbed (like miniature versions of beefsteak tomatoes). The ones we see mainly today have been cultivated to be a size suited to various uses, which is why we get everything from cherry tomatoes, through salad tomatoes, to plum tomatoes (for cooking) and beefsteaks.
Tomatoes have to be moved from farms to homes, and quite often the farms are in a different country from the homes. So many tomatoes are picked when they are still green and ripened in a controlled way while they are being stored. In this way they can be released onto the market over along period, and tomatoes are available through the year in most shops.
Tomatoes are round, and this is not very useful for putting them in cans because it wastes a lot of space. So a squarer form of tomato was cultivated – plum tomatoes. This tomato can be harvested by machine, and then tinned as soon as they reach the packing station. Most canned tomatoes are of this variety. Open a can and check! Their shape is not because they have been squashed in the can, but because thy have been bred to be long and square.
