Determinate vs. Indeterminate
I know many of you are starting your gardens indoors and some are new at the gardening game so I thought I'd offer you a couple of terms you may not be familiar with in regards to tomatoes.
A determinate tomato is also called a bush tomato. They generally grow to about 4 feet and don't have to be staked. The plant stops growing when it fruits from it's top most or terminal bud, it ripens all it's fruit and once and then dies. Why would you want a plant like that? Well, since it harvests at once it's much easier to can tomatoes when the crop is ready at one time. If you have a short growing season this might be a very good choice. These guys should not be suckered (pruning the stems that form in the axil between leaves and main plant) since this will drastically reduce the crop the plant can produce. Some common determinate varieties are: Patio, Heat Wave, Roma, Celebrity and Rutgers.
An indeterminate tomato is sometimes called a vining tomato. They can grow to 10 feet tall but generally achieve about 6 feet. They must be caged or staked and whether you sucker the plant or not is up to you. They grow and produce until frost kills the plant. You will usually have blooms, set fruit and ripe fruit all on the plant at the same time. Why grow these? You can pick tomatoes in smaller numbers throughout the growing season. Dandies for salads, hamburgers are just for eating. Some common varieties are: Early Girl, Champion, Jet Star, Better Boy, Big Boy, Mortgage Lifter and Brandywine. There are far more indeterminate varieties than determinate.
There is also a variety called semi-determinate. There aren't very many varieties. They were bred to have the best of both worlds. They are shorter than indeterminate but grow all year. About the only one I can think of is: Heartland although I'm sure there are others.
Knowing what you want from your tomatoes (bountiful crop all at once or tomatoes throughout the season) and matching your expectations to the proper tomato variety will ensure you have the crop you want.
