When purchasing tomato plants the tag should indicate whether the plant is Determinate (Det) or Indeterminate (Ind). Also, the tag should let you know approximate maturity date. And if all goes to plan, one will have tomatoes by that date.
Determinate varieties of tomatoes, also called “bush” tomatoes, are varieties that are bred to grow to a compact height (approx. 4 feet). Grow to a determine size. With flowers blossom at the tips of the branches, when the plant has reached its full height. The fruit of a determinate tomato plant ripens all at once. At least within a few days. Because of this trait, this type of tomato plant is useful for those who want to grow tomatoes for canning or needs all the crop in a short window of time. This plant should not be pruned. After fruiting the plant can be discarded. It is possible to take cuttings from the plant and start new plants from them. Determinate tomatoes plants require a limited amount of caging and/or staking for support, should NOT be pruned or “suckered” as it severely reduces the crop, and will perform relatively well in a container (minimum size of 5-6 gallon). Examples are: Rutgers, Roma, Celebrity (called a semi-determinate by some), and Marglobe.
Indeterminate varieties of tomatoes are also called “vining” tomatoes. They will grow and produce fruit until killed by frost and can reach heights of up to 10 feet. They will bloom, set new fruit and ripen fruit all at the same time throughout the growing season. This type continues to produce tomatoes all growing season until a hard frost hits and stops them in their tracks.
Some gardeners remove suckers between the main stem and leave stem. Whether removal of these suckers increases fruit production is debatable. Removing the suckers does allow the main plant to have more nutrition from the soil. Suckers can be potted to grow a new plant. Remove the sucker with a sharp knife, trim leaves to about 1/2 size and plant in potting medium until new growth appears.
For both plants water on the surface (soil level) and minimize any splash on the plant. This will assist in keeping the plant healthy.