Seeds from an open-pollinated variety produce offspring that are identical to the parent plant. As long as cross-pollination can be prevented, seeds that are saved will produce identical tomatoes year after year. Seed saved from a hybrid tomato plant or from cross-pollinated plants will not generally grow true to type.
Heirloom tomatoes come in a multitude of sizes, shapes, colors, and flavors. In addition to red, they can be purple, yellow, green, orange, or pink, and they can even be striped or marbled. They also vary in shape (pear, oblong, round, oval) and size (from small grape-sized fruit to giant two-pounders). And heirlooms can have a long harvest season, producing fruit into fall if conditions are right.
Heirlooms have often been named along the way with quirky monikers like “Black Krim,” “Cherokee Purple,” “Missouri Pink Love Apple,” or “Hillbilly Potato Leaf.” If the seeds have been passed down within a family, there is usually a written history about the variety. They may be mentioned in an old seed catalog, a state agricultural report, or a garden book or journal.
We grow them for their wonderful flavor, texture, and taste, but it is interesting to learn the stories that go along with each tomato. The person from the past that created a certain variety over 50 or 100 years ago reaches down, through time, to deliver the same tomato seed that we can plant from year to year in our own gardens. These unique stories are usually included along with the tomato’s description in seed catalogs or the back of seed packets.
There are both determinate and indeterminate varieties of heirloom tomatoes. Determinate varieties are sometimes smaller plants that work well in containers. The fruit ripens all at once so they are good for batch projects like making tomato sauce for canning or freezing. Indeterminate tomatoes bloom and ripen at different intervals throughout the season and bear fruit for a longer period of time.
The Back Story
The tomato is a New World fruit, native to Mexico and Central America, where the Aztecs and Incas cultivated it as early as 700 AD. During the Age of Exploration in the 1500s it was introduced to Spain, Portugal, and Italy. In the mid 1800s the tomato became a staple in kitchen gardens in the United States.
Over the next 100 years, tomatoes were grown by home gardeners or by farmers for local markets. These tomatoes were fragile and did not travel well. Hybridization began commercially, in order to breed a tomato that could travel long distances.
Cultivating Heirloom Tomatoes
There are some challenges with growing heirlooms. They can be less reliable than hybrids from year to year, and may produce less fruit. Their fruit can develop cracks in the heat, or be less disease resistant. They might produce well in one climate zone and not in another one.
Experiment and find what works well in your garden.
Next week: Growing Tomatoes, Part 1
■ For more gardening advice or topics from the Colusa County Master Gardeners, visit http://cecolusa.ucanr.edu