There are thousands of tomato varieties in seed catalogs and nursery stock that can boggle the mind of the gardener who is attempting to make the right choice of tomatoes for their garden this year.  Knowing some of the basics will help make your choice of variety much easier and more enjoyable to grow.  

There are two main classifications of tomato growth habit that one needs to understand in order to determine the most suitable variety for their particular garden.  Keeping in mind that cultural practices, fertilization, group prep and watering needs are generally the same.  

 Determinate Tomatoes  

Determinate tomatoes have a predetermined genetic quality the causes the plant to:    

• Have a bush like habit, often called "bush" tomatoes 
• The plant will grow vertically at first, and then stop and the remainder of growth will take place on the side shoots  
• Growth habit is approximately 4" tall or less
• Crop bearing is over the course of four or five weeks and then it is done    
• The plant requires minimal staking
• Tend to be more compact and manageable, but not always 
• Suitable for container planting and will perform well in 5 gal pots  
• Determinate Tomatoes do not require heavy pruning or sucker removal for good crop yield
• Examples of determinate tomato varieties are:  Rutgers, Roma Celebrity  

 Indeterminate Tomatoes

Indeterminate tomatoes are distinguished by having the following features:  

• Often Called "vining" tomatoes because they will continue to flower and bear fruit over the course of the season until the plant is killed by frost
• Can grow 6" or more
• They require staking or caging for support
• Require removal of suckers, wait until two leaves develop before removing 

Remove the sucker

• Plants with two or more stems produce more tomatoes with better foliage protection from the sun than plants with one stem. However, tomatoes pruned to one leader will bear earlier but with less yield over all. Choose the stems you want to keep and pinch out the others as they develop. A dense leaf canopy may reduce the incidence of black mold and cracking but may increase the incidence of other fruit molds such as gray mold. 
• Look for packaging that says IND or INDET, or Indeterminate 
• Remember that hairloom varieties are not as resistant to disease as other varieties Examples of Indeterminate Varieties Include:  Beefsteak, Goldie, Cherry, Early some heirloom

Resistant Varieties for both Determinate and Indeterminate Tomatoes include some of the following: 

A  Alternia (early blight) stem canker;, "VFN" indicates the variety is resistant to Verticillium wilt, Fusarium wilt (generally both races of the Fusarium wilt fungus), and root-knot nematodes. Varieties which carry a "T" designation are also resistant to tobacco mosaic virus, a disease which often causes problems for tomato gardeners. Some of the listed varieties are also resistant to other disease pests. Varieties which carry the designation "VF" only are resistant to Verticillium and Fusarium wilts. FF- fusarium races 1 and 2; FFF fusarium races 1,2, and 3; ST, stemphyleum, gray leaf spot;   

 Some examples with Nematode resistance include:    Park's Whopper Improved VFNT, , Better Boy VFN, Celebrity VFN

Bibliography: 

• 
  http://www.ipm.ucdavis.edu/PMG/GARDEN/VEGES/CULTURAL/tompruning.html
• Infobytes newsletter was written by the late Dr. Frank Killebrew, Extension Specialist. Mar 1999, http://msucares.com/newsletters/pests/infobytes/19990325.htm