Enthusiasts say heirloom vegetables offer more flavour, nostalgia and authenticity.
"I think it's all about the flavour," said Kathy Mendelson, a botanist from the Seattle area and author of a website called "The Heirloom Vegetable Gardener's Assistant."
"Nobody wants a plateful of bland for dinner, and the best of the heirlooms have flavours that are complicated - delicate, bold, sweet, not sweet, rich, distinctive and more," Mendelson said.
Nostalgia plays an important part, too, she said, but heirlooms are more than just sentimental favourites: "For example, they can have to do with family, community, certainly with culture, and also History with a capital 'H' - researched and documented."
What's not to love when growing tomatoes from seeds given such descriptive names as "Radiator Charlie's Mortgage Lifter," ''Brandywine," ''Trucker's Favorite" or "Amish Paste"?
Tomatoes are the favourite heirlooms, but have been eclipsed in the marketplace by hybrid varieties created for disease resistance, appearance and longer shelf life.
"Breeding has changed," said Diane Ott Whealy, co-founder of Seed Savers Exchange in Decorah, Iowa, the largest non-government seed bank in the United States.
"Commercial growers wanted vegetables like tomatoes to ripen off the vine, survive being shipped cross-country and then mature in warehouses before going into stores," she said, but added that they misplaced something in the process: flavour.
"People come to us and say they remember the juicy tomato from their grandmother's garden. Tomatoes in markets today just don't have that," Ott Whealy said.
Along with scores of heirloom tomato varieties, old-school squash, potatoes, beans, peppers, cucumbers, carrots, herbs and melons also are popular with modern-day gardeners.
And let's not forget heirloom flowers.
"Genetics over time has made them stronger, more diverse," Ott Whealy said. "Heirloom flowers have more pollen and more nectar for butterflies. Many new varieties of flowers are bred without that."
Heirloom vegetables may not be as disease-resistant as many modern cultivars bred specifically for that characteristic, but they are proven survivors, said Sarah Browning, an extension horticulturist with the University of Nebraska-Lincoln.
"Heirloom plants were created by gardeners who repeatedly saved seed from the healthiest, most productive and flavourful plants from their garden," Browning said. "So inadvertently, these gardeners also selected for disease resistance."
Once you start growing something, you might want to save a few seeds or choose a variety that has some history or that was grown for years by your own family, Ott Whealy said.
"Saving seeds is saving heritage, and I think it will be done in backyard gardens rather than the corporate kind," she said.
For more about growing heirloom vegetables, see this Clemson University Home and Garden Information Center Fact Sheet: http://clemson.edu/extension/hgic/plants/vegetables/gardening/hgic1255.html .
For a huge database of plants - heirloom and otherwise - in catalogues and nurseries, tap this University of Minnesota link: http://plantinfo.umn.edu .
You can contact Dean Fosdick at deanfosdick(at)netscape.net.