What to look for in a short-season tomatoThe challenge of growing tomatoes in an area where spring comes late or summer temperatures are cool is that most tomatoes require heat to produce the sugar that makes them sweet. And then there is the problem of pollination, which of course is necessary for a tomato plant to fruit at all.
"Tomatoes require warmer temperatures to produce pollen and pollinate," says Randy Gardner, a professor at the Mountain Horticultural Crops Research and Extension Center in Fletcher, North Carolina, who specializes in hybridizing tomatoes and other vegetables.
What makes some of the newly introduced varieties so different? The plants begin producing fruit without bothering to wait for the flowers to pollinate. (This quality, called by the fancy name of "parthenocarpic," also means that these tomatoes are naturally seedless, at least early in the season.) If you live in an area with unusually cool, cloudy weather, you want to look for parthenocarpic tomatoes because you'll get fruit whether the plants pollinate or not, says Jim Myers, professor of vegetable breeding and horticulture at Oregon State University in Corvallis, Oregon. One of Myers' most popular new tomatoes is a variety called Legend. "If you start it early, you can have fruit by the third week of July, and it will set fruit even in greenhouses," he says.
Oddly enough, those who live in areas with extremely hot summers, such as the Southwest, also get good results with the fastest-fruiting varieties developed for cool climes, he says. "I've heard from some people that Oregon Spring is the only tomato that will set fruit during a summer in Arizona," Myers says. The reason? Extreme heat in June and July also interferes with pollination, so growers have to stick to varieties that fruit in 55 to 65 days. Another idea to try: Plant smaller, bushy determinate tomato varieties in containers, then move them into the shade during the middle of the day.
Many of the other short-season varieties come out of Russia and other Eastern European countries, because tomatoes there naturally evolved to accommodate late snows and early frosts, Ibsen says. These new heirloom varieties so named because they were passed on from generation to generation have all the prized qualities of heirlooms such as unusual colors, shapes, and flavors and yet are hardy and disease resistant as well.