One of the most popular of all home garden vegetables is the tomato. Originating in Central and South America, the tomato was thought by early American colonists to be poisonous and was not recognized as a useful vegetable until the 1800s. Eaten raw or in innumerable cooked dishes, today the tomato is an almost daily part of the American diet. When grown as staked plants, tomatoes require a relatively small amount of space, yet are capable of producing 8 to 10 pounds or more of fruit per plant. Tomatoes are low in calories and a good source of vitamin C.

Climatic Requirements:

Tomatoes are warm-season plants and should be planted only after danger of frost has passed. Temperature is an important factor in the production of tomatoes, which are particularly sensitive to low night temperatures. Blossom drop can occur in early spring when daytime temperatures are warm but night temperatures fall below 55 degrees F, as well as in summer when days are above 90 degrees F and nights above 76 degrees F.

Soil Requirements:

Tomatoes can be grown on many different soil types, but a deep, loamy soil, well-drained and supplied with organic matter and nutrients is most suitable. As with most garden vegetables, tomatoes grow best in a slightly acid soil with a pH of 6.2 to 6.8.

Fertilizer:

Tomatoes respond well to fertilizer applications, especially phosphorus. Excess nitrogen fertilizer can result in plants with extremely vigorous vine growth but little fruit production. Apply 2-1/2 to 3 pounds of a complete fertilizer, such as 5-10-10, 5-20-20 or 8-16-16 per 100 square feet of garden area. Work the fertilizer into the soil about 2 weeks before planting. An additional sidedressing of a nitrogen fertilizer may be desirable after the first cluster of flowers have set fruit.

Recommended Cultivars:

There are probably more tomato cultivars available to the home gardener than any other garden vegetable. When choosing cultivars, keep in mind the different ripening periods. Tomatoes are usually categorized as early, mid-season or late. Another consideration is whether the tomato cultivar you choose is determinate or indeterminate in growth habit. Determinate (D) tomato plants grow to a certain height and then stop. They also flower and set all their fruit within a relatively short period of time. This is an advantage if the tomatoes are being grown primarily for canning purposes. Indeterminate tomato plants grow, flower and set fruit over the entire growing season. Another characteristic to look for when choosing tomato cultivars is disease resistance. Many cultivar names are followed by one or more letters indicating resistance to Verticillium wilt (V), Fusarium wilt (F) or nematodes (N). Disease resistance can be an important consideration, especially if you have experienced these problems with tomatoes in the past.

Establishing the Plants:

Due to their long growing season and temperature requirements, tomatoes are set out as transplants in gardens in the Northeast. Tomatoes may be planted anytime after the last spring frost date. When purchasing tomato transplants, choose those with straight, sturdy stems about the thickness of a pencil. They should have 4 to 6 young true leaves, no blossoms or fruit and be free of insect pests and diseases.

Plants in individual containers or cell packs experience little or no transplant shock and become established quickly. Tomato plants will develop roots along the stem and may be set deeply at transplanting with the first set of leaves near the soil surface. If transplants are in peat pots, remove the rim of the pot or be sure the rim is below the soil surface so that the soil ball will not dry out.

A soluble starter fertilizer high in phosphorus can be applied at planting time. Use according to label directions.

Tomatoes grown unstaked are usually planted 3 feet apart in rows 5 feet apart. Plants to be staked are planted 2 feet apart in rows 3 to 4 feet apart. Plants to be caged are planted 30 to 36 inches apart. Stakes and cages should be placed at planting time or soon after so as to not disturb the roots. Unstaked plants should be mulched with clean straw, black plastic or another suitable material to keep the fruit off the ground and prevent rotting.

Where space is limited or soil conditions poor, tomato plants can be grown in containers using a disease-free planting mix. Any container with adequate drainage is suitable. Pay special attention to water and fertilizer needs of container-grown tomato plants.

Cultural Practices:

Once the tomato plants are established, apply a mulch to conserve moisture and suppress weed growth. If weeds do appear, they may be pulled by hand or removed by shallow cultivation. An even moisture supply is important, especially once the tomato fruits begin to develop. If the soil becomes too dry, blossom-end rot can be a problem. If too much water is applied at one time, ripening fruit may split.

Staked plants are usually pruned to a single or double stem and periodically tied loosely to the stake with soft twine. Pruning is accomplished by removing all the branches or "suckers" that grow from the leaf axils, leaving only the main stem or the main stem and one additional branch near the base. Unsupported and caged tomatoes may be left to branch normally. Staked and pruned tomatoes produce fewer but larger fruit than caged or unsupported plants.

Adapted from Marianne Riofrio, Ohio State University Extension, 2000