Jan 15, 2015

Heirloom tomato growers benefit from new varieties

There was a time when heirloom tomatoes were typically associated with production, handling and shipping challenges that did not attract commercial growers.

According to Jeanine Davis, North Carolina State University (NCSU) horticulturalist and Extension specialist, the negative sentiment toward these varieties may be shifting in another direction as growers realize the high profit potential of heirlooms.

“There are many definitions for what constitutes an heirloom tomato variety, but the one I generally use is that it has been available for 30 to 50 years or more, it is open pollinated, the seed has been passed on from generation to generation, and it has some special characteristics that make people go through all this trouble to keep the variety alive,” Davis said during the Great Lakes Fruit, Vegetable & Farm Market EXPO in Grand Rapids, Michigan.

Davis said the heirloom tomato movement really took off eight to 10 years ago, when chefs and consumers started looking for an alternative to the standard supermarket tomato. She said they often spoke of wanting a tomato “like Grandma used to grow in her garden.”

Backyard gardeners suddenly found their homegrown tomatoes to be in high demand, and some started selling their excess tomatoes to local chefs and at tailgate markets. Organic growers were the next to catch on to the movement, and began growing some of the most popular heirloom tomato varieties for local sales.

In time, Davis said, large-scale tomato growers also entered the market, and now heirloom tomatoes are sold right next to all the other tomatoes in the supermarket but at much higher prices.

Surveys Davis has conducted reveal consumers usually find heirloom tomatoes to be more flavorful, juicy and with thinner skins than the standard tomato.

“They like that heirloom tomatoes come in a wide array of shapes, colors and sizes,” she said. “They like the fun and interesting names that many heirloom tomatoes have, and many people report that they enjoy the nostalgia that comes with eating a tomato variety they associate with their youth. And for many consumers, they just want something different.”

So why don’t all tomato growers produce heirlooms?

“The list is long, but the main reasons are that heirloom tomatoes tend to be thin-skinned so they crack, burst and bruise easily, and most are not uniform in shape and size,” she said. “Those factors alone result in high cullage and difficulty in shipping. Many heirloom varieties have little or no disease resistance, making them particularly challenging to grow organically or in warm, wet regions.”

Davis said many heirloom varieties are indeterminate, requiring trellises or taller staking systems than modern determinate varieties. There can be a great deal of variability from one seed lot to another, and yield and quality are often much less than with modern hybrids.

“Production of heirloom tomatoes can be quite profitable,” Davis said. “In our research plots we have some varieties, such as Red Brandywine, which can produce 9.2 pounds of marketable fruit per plant. At a conservative retail price of $2.50 per pound, that translates into a gross return of $23 per plant.”

At a local tailgate market this past summer, Davis said, Brandywine tomatoes were selling for $5 per pound; that would produce a gross return of $46 per plant.

“But that is under the best of circumstances,” she said. “Under wet conditions or high disease pressure, especially early blight, late blight and septoria, yields per plant could be 2 pounds or less. As one heirloom tomato grower told me, ‘When you grow heirloom tomatoes you are playing Russian roulette with the weather. You never know what your yields are going to be, but at least, up to this point, you can always sell whatever you grow.'”

Growing heirlooms

Because heirloom tomatoes are so susceptible to cracking and disease, the best production usually occurs in high tunnels or greenhouses. Following greenhouse tomato-growing guidelines often results in a successful outcome, since most greenhouse tomato varieties are also indeterminate, Davis said.

Most growers want to produce their heirloom tomatoes outside, in the open, along with their other tomatoes.

“Again, since most heirloom tomatoes are indeterminate, a taller and stronger support system is needed to produce them than modern hybrid tomatoes, which are usually determinate. And I don’t know anyone who is successful at growing heirloom tomatoes on the ground.”

She outlined differences in standard short-stake systems for determinate tomatoes, a short-high stake system for indeterminate tomatoes and a traditional trellis system for indeterminate tomatoes.

Black plastic mulch and drip irrigation is commonly used in all these systems. A standard trellis system consists of positioning 7- to 8-foot-long posts about 15 feet apart in the row and running a top and bottom wire to tie the strings to. Plants are often spaced 8 to 12 inches apart in the row and trained to a single stem to climb the string.

“This is a sturdy system that works very well but has a high initial cost,” she said. “If a grower can rotate different crops on it from year to year (e.g., cucumbers, beans, specialty melons and then tomatoes again), it can be cost effective. Dismantling and resetting a trellis in a new location each year can make this system cost prohibitive.”

The short-high stake system consists of constructing a standard staked system using 4-foot-long stakes set with two plants between each stake. The plants are often set 18 to 24 inches apart in the row and pruned to several stems. Right before putting the last string on the short stakes, 5- to 6-foot long stakes are added at every other stake. In this system, the plants need to be topped when they reach the top of the tallest stakes.

“This system is more economical than a trellis system but can be more vulnerable to wind damage,” Davis said. “The longer stakes must often be special ordered, so plan accordingly.”

Following a preventative disease management system is “very important” for heirloom tomatoes, whether they are grown organically or not.

“Know which diseases you are probably going to be dealing with, follow forecasting models for late blight and use preventative sprays for it, and use sprayers that provide excellent coverage.

“Know your varieties so you know what to expect for yields and maturity. Some varieties produce over a long season and some have a very concentrated set. Be prepared to harvest, handle and sell these fragile tomatoes differently than standard fresh tomatoes.”

Popular heirloom varieties

“The three heirloom varieties that had the best yields and consumer acceptance in our trials in western North Carolina are German Johnson, Cherokee Purple and Mr. Stripey,” she said. “Brandywine is a perennial favorite that many consumers will ask for, but we have found there is a lot of variability between seed sources and it doesn’t rate very high in taste tests.”

Breeding has improved “heirloom-type” tomatoes, Davis said.

She said public and private tomato breeders have heard what the consumers want and have been working to develop new tomatoes that fit the heirloom category. At NCSU, they refer to these as “heirloom-type hybrids.” NCSU tomato breeders Randy Gardner and Dilip Panthee have been working to create tomatoes with all the desirable characteristics of heirloom tomatoes (taste, shape and color) with the vigor, disease resistance, uniformity, smooth appearance, yields and good shipping qualities found in modern hybrids.

“Both of these breeders are also interested in improved nutritional characteristics,” Davis said. “My role in these studies has been to conduct the taste tests to ensure that these new varieties taste as good as or better than heirloom varieties.”

The first release from Gardner’s heirloom-type breeding program is a hybrid variety known as Mountain Magic. It is a compact indeterminate plant that produces round fruit about 2 ounces in size, similar to the greenhouse variety Campari.

“Mountain Magic has excellent flavor, beating out all the heirloom tomatoes for several years running in our consumer taste tests,” Davis said. “It also has moderate early blight resistance and a high level of late blight resistance, making it a favorite among organic tomato growers. It is readily available.”

A larger-fruited release from Panthee and Gardner’s program is Mountain Rouge.

“It is a hybrid with Pink Brandywine as a parent, so it is a desirable pink color with a high level of late blight resistance,” Davis said. “It has a vigorous indeterminate growth habit and excellent fruit flavor and texture. It is, however, subject to fruit cracking. It should be commercially available in 2015.

“I am very excited about the new lines that Randy Gardner is working on,” Davis said. “He is working on striped tomatoes in red, pink, purple and brown variations.”

Davis said he is also working on open-pollinated varieties that will be attractive to organic growers, home gardeners and permaculture practitioners who want to save their own seed from year to year.

The bottom line

“The customer is always right, and the customer wants very flavorful tomatoes available in a wide variety of colors, shapes and sizes,” Davis said. “Right now, growers must rely heavily on heirloom tomato varieties to fill that niche, and take all the risks that come with growing them.”

As time progresses, Davis said, more improved “heirloom-type” tomatoes will be available.

“Growers should start educating consumers now about why these improved varieties are better for the grower, and as a result should bring the price of these tomatoes within reach of all consumers,” Davis said.

For more information on Davis’ work, click here.

– Gary Pullano