Tomatoes are a naturally vining plant. Stakes give support and cages minimize contact with soil and allow sun to ripen fruit. Photo: David S. Walker
In 2020, scientists announced the discovery of the missing link between modern tomatoes and their wild ancestors. Using genome sequencing, a wild species in Ecuador and Peru was confirmed as long as 80,000 years ago. About 7,000 years ago, wild tomato plants with fruit the size of blueberries were bred to produce cherry-sized tomatoes. Mesoamerican farmers eventually bred these into our modern tomatoes, which grow best where temperatures are no higher than 90 degrees and no cooler than 55 degrees. It’s no wonder so many pathogens plague this tropical plant.The plentiful harvest is displayed in a hand thrown colander from Peru, home of wild ancestor tomatoes. Photo: Anne-Marie Walker
By mid to late summer, gardeners invariably ask each other “How are your tomatoes?” So, we worry if our tomatoes are getting enough sun, enough water, or are they getting blight? Are they splitting or besieged by pests? Ultimately of most concern, “Are they sweet enough?” The tomato seed you select to plant is your first big decision. I like to pick a mix of heirloom and hybrid seeds. Research points to higher sugar content in heirlooms and disease resistance is better in hybrids. During domestication, favorable taste genes got lost while crop yield, disease resistance and transportation friendly traits got emphasized. Ongoing research at UC Davis Tomato Genetic Resource Center focuses on retaining flavor while advancing disease resistance and crop yield. At the University of Florida, research defines ideal flavor as a complex blend of sweet and sour. For gardeners, the important takeaway is high sugar and high acid content in tomatoes is greatly influenced by sunlight reaching the fruit, plant nutrition and healthy soil. Grow tests demonstrate healthy soil translates to sweet taste that can’t be achieved with fertilizer supplements.Enjoy a simple but glorious salad of sliced tomatoes, fresh mozzarella & homegrown lemon basil. Drizzle with balsalmic vinegar. Photo: David S. Walker
To learn more, go to marinmg.org and click on the link to Edibles, then Tomatoes to get a more complete how-to guide for starting tomatoes from seed.