Tomatoes 101, Part II

By David Wall
Guest Columnist
The number of tomato varieties is unknown, but the literature estimates as many as 25,000.  Many, however, say so many tomatoes; so little space! Within these varieties, there are three basic classifications.
First, tomatoes are genetically considered either heirloom (open pollinated) or hybrid.  Heirlooms have been around for at least three generations without being cross-bred with another variety, but there are heirlooms that have been with us for hundreds of years.
They offer stability, good taste, and disease resistance, while taking longer to mature than hybrids and are sometimes misshapen.
Hybrid tomatoes are cross-bred between two different varieties.  Hybrids are normally created by commercial seed companies, but cross breeding can occur in your own garden.  Heirloom varieties may or not be listed as such, but hybrids are nearly always listed as hybrid on the package or seedling.
Next, tomatoes are determinate, semi-determinate or indeterminate. The difference is the time span for producing the fruit. Determinate tomatoes produce for two to several weeks and then stop, as they are done for the year. They produce a flower on their growing tips, stopping growth.
Semi-determinates may or not produce tip flowers. If not, they can produce a second crop in the fall.  Indeterminate plants never produce tip flowers, keep growing, and can produce until frost.
The final classification is tomato shape. The shapes include globe, beefsteak, paste and cherry. Globe tomatoes are the ones we see most often in grocery stores and farmers’’ markets.  Beefsteaks are the biggest tomatoes, many of which are determinate. Paste tomatoes are used in sauces, while cherry tomatoes are the smallest and also include grape tomatoes.
Read up on the type of tomatoes to determine what you want.  If you choose a determinate, you can always get a second crop by starting new seeds in early July.