WASHINGTON -- It may seem contradictory that the smaller the tomato, the larger the plant on which it grows. But when one realizes that the original wild tomato, which still grows in abundance in its native South America, is a small-fruited, wildly vining plant, the logic of the tomato's natural habit becomes clear.
That is not to say that large-fruited types are diminutive. Beefsteak varieties, which bear the largest and, some would say, the best tomatoes, typically reach seven feet or higher. Still, these do not come close to the abundance of such heavily fruiting varieties as Sweet Million or Sweet Chelsey. A cherry tomato plant can reach 13 feet tall and six feet wide. Currant tomatoes -- the smallest fruited and closest to the wild varieties -- wander about in luxuriant waves of green, blanketing 50 square feet if they are not contained.
Tomato enthusiasts who grow their own are aware that most varieties need support when cultivated at home. Plants left to ramble have greater disease problems; the fruits themselves are prone to damage and decay when they touch damp or wet ground; harvest is difficult and tomatoes go unpicked.
A few varieties need little or no support. The best-known is the Patio tomato, which has a strong central stem like a small tree and dense foliage that grows almost stiffly, always well-contained. This tomato can be grown with no support at all, but does benefit from something as minimal as a stout stake, two to three feet tall, thrust into the ground next to it when it is planted.
"Bush" varieties, such as Better Bush, also need support, but a somewhat-taller stake -- four-foot or so -- or one of those cone-shaped wire rings sold in garden and home centers would do nicely. Italian or plum tomatoes, such as Roma, or the improved Super Roma, Viva Italia or San Marzano, are less rampant than beefsteak and cherry varieties. I have found that these sauce-tomato plants do well with the same level of support as bush types. But all other varieties need a great deal more support, especially the popular indeterminate types. These include such common varieties as Better Boy, Big Beef and Beefmaster. Indeterminates continue to grow and bear until the cool nights of October.
As a result, they need a stake or post as thick as your arm and as tall as yourself. Alternatively, a tall sheet of wire mesh, formed into a cylinder, will do the job. The purpose-made cone-shaped wire tomato cages are too small for all but the smallest of tomato varieties. They are useful for pepper plants but not for a vigorous cherry or beefsteak tomato.
Whether you stake or cage your plants, supports should be in place when seedlings or young plants go into the ground -- before Memorial Day if you want to be sure of a good harvest. Staking works best when the plant is trained up onto the post. That involves pruning large side stems, limiting the plant to one or two main stalks that are fastened to the post with soft ties, such as rags or plastic ribbon. Aficionados of staking tomatoes find that they gain size of individual fruits, while perhaps sacrificing actual numbers. It comes out about equal in terms of total weight of the harvest, according to most studies that have compared staking to caging tomatoes.
Caging tomatoes is a plant-it-and-forget-it way of growing them. The dimensions of the cage are key -- at least five feet tall and three feet in diameter. Some cages have tongs at the base that are thrust into the ground to secure it. Those that do not have these should be secured with stakes. The gardener who thinks this is a bit of overkill (why would such a weedy seedling need a fortress?) need only visit a tomato-laden garden in August to see massive plants enveloping even large cages. In addition, notorious August storms will whip and tip insecure tomato cages, causing all sorts of damage.