Heirloom tomatoes are a farm-to-fork favorite.

Some consumers are willing to pay a hefty price at trendy restaurants, farmers markets, roadside stands, and even local grocery stores for tomatoes with irregular shapes, vivid colors and rich tomato flavor.

The consumer demand presents an opportunity for small-scale farmers, and a challenge.

“It's not easy to grow heirloom varieties,” said Margaret Lloyd, the UC Cooperative Extension small-scale farm advisor for Yolo, Solano and Sacramento counties. “They often have less disease resistance, are lower yielding and cannot tolerate as much stress as improved modern varieties.”

When Lloyd joined UCCE last summer, she began visiting small-scale producers in the counties she serves.

“I realized very quickly how important fresh market tomatoes are to these growers,” Lloyd said.

Because she holds a doctorate degree in plant pathology from UC Davis, Lloyd is well-positioned to begin her research program with a small tomato grafting project on UC Davis farmland. Her idea is grafting the particularly delicious heirloom varieties onto tomato roots that are resistant to soil-borne diseases.

“Grafting is an old technology,” Lloyd said.  “It works in the same way we graft fruit trees and grapevines onto favorable rootstocks. Vegetable grafting has also been done for years.”

Lloyd said the process is simple and an individual can easily learn to graft tomatoes. But to do so cost effectively with the quality and success rate necessary for economically viable production, it may make most sense to work with a commercial nursery.

Lloyd is conducting a quarter-acre field trial with the three most common heirloom varieties – Brandywine, Cherokee purple and Marvel stripe – plus the yellow-hued Sun Gold cherry tomato and a non-heirloom salad tomato, Charger.  Several growers in the area have also planted them in their commercial operations.

In addition to collecting data from the trial that will help small farmers decide whether grafted tomatoes make sense for their operations, Lloyd and her research associates will harvest many bushels of fresh tomatoes from the plots. Some will be sold at the UC Davis farm store to help support the research, and as for the rest, “We're definitely going to eat them,” Lloyd said.

“I enjoy them raw with olive oil, salt, vinegar and a little basil,” she said.