LEFT: Bill Warmerdam and son John grow and pack their own tree fruit in addition to packing cherries, apples, and kiwis for other growers. BELOW: Snow Fall peaches, a white-fleshed variety, are packed in late September.

LEFT: Bill Warmerdam and son John grow and pack their own tree fruit in addition to packing cherries, apples, and kiwis for other growers. BELOW: Snow Fall peaches, a white-fleshed variety, are packed in late September.

The father and son team at Warmerdam Packing, LLC, sees cherries as a way to help differentiate themselves in the market from other California stone fruit growers and shippers. With 300 acres of cherries already in production and more on the way, they have concentrated their efforts in production and packing in recent years to expand their cherry base.

Bill and Audrey Warmerdam founded Warmerdam Packing, located in Hanford, more than 40 years ago. Bill is still president, while his son John is general manager and oversees field operations. The company packs about 1.3 million boxes annually, with most of the volume representing their own peaches, plums, nectarines, apples, and cherries. Organics are a small, but growing part of their stone fruit production, with several blocks either certified or in transition for organic certification. A few years ago, they began handling kiwi fruit to better utilize cold storage rooms and packing lines in winter months. Trinity Fruit Sales in Fresno markets their fruit.

At the peak of their apple production, they had 250 acres of Granny Smith, Gala, and Fuji varieties. Much of the apple acreage is now gone, John Warmerdam said, because the market didn’t support the cost of tools needed to grow quality apples. About 100 acres of Grannies were pushed last fall.

Though the Hanford area is known for its walnuts, cotton, and milk cows, the Warmerdams have found success growing a variety of stone fruit in the fertile soil of the San Joaquin Valley, including a white-fleshed peach called Snow Fall for the export market.


Diversifying into additional cherry varieties is also a strategic labor management tool. The Warmerdams hire seasonal workers earlier than most farmers and keep them employed longer than other growers because the workers can move from stone fruit thinning to picking cherries and then back to harvesting peaches, plums, and nectarines.

“All of our expansion in cherries has been with Sequoia and Rainier varieties,” John said. Sequoia is the brand name for three early season cherry varieties, Glen Red, Glen Rock, and Glenoia, that were licensed to Warmerdam Packing by Bradford Genetics last year. The varieties are similar in fruit characteristics but mature within a week of each other.

Selected growers have planted some 500 acres of Glen Red in California, John said, although only a small amount of acreage is currently bearing fruit.

“With cherries, we can distinguish ourselves from the crowd,” he said. “Quality and timing can set you apart. That’s why I’m optimistic about cherries. But with stone fruit, it’s much harder to distinguish yourself from others.”

The timing of their cherries falls in between those grown in the southern San Joaquin Valley and the northern Lodi cherry district. “We can’t compete to be the earliest because we are about seven to ten days behind the early districts. We try to compete on quality, size, and yield. We’re not too concerned about timing.”

Colt rootstock is used in nearly all of their cherry orchards because “Mahaleb trees want to die and Mazzard are too vigorous, growing upright with a lot of blank wood,” he explained.

Inconsistent cropping of cherry trees is a common problem in California, John said. “Variability of the crop is a big issue. Growers are looking at different rootstocks like Gisela and a new interstem to help grow more consistent crops.”

The dwarfing Gisela rootstocks may have potential in their area, he said, but growers will need to learn how to grow the rootstock in the hot, dry climate and manage irrigation carefully to avoid water stress.

They apply the plant growth regulator Dormex (hydrogen cyanamide) to nearly all of their cherry orchards to induce early and more uniform bloom and avoid having them ripen along with Bing.

When they planted their first cherries in 1989, trees were spaced at the same spacing they used for peach trees: 16-foot-wide rows with 20 feet between the trees. Since then, they have tightened it up to 12-foot-wide rows by 16 feet, although John is concerned that might be too tight.

“Growers in our area still have a lot to learn about cherries—even us,” he said, adding that most are peach growers trying to grow cherries like peach trees. “Because applied research for the southern district is inadequate, we have to do it on our own and work with others. It’s the blind leading the blind, but we’re making improvements.”

Trees are trained to the steep leader, though he is experimenting with modifying the steep leader system to have two scaffolds on each side of the row, with laterals uniformly spaced to grow horizontal and perpendicular to the scaffolds. The system would optimize light distribution within the tree, even at the bottom of the tree.

While the modified system is still conceptual, John envisions it to be more labor efficient because harvest aids could be used, including mechanical harvesting. Tree height is not as critical if mechanical harvest aids are used. “It’s a new training system that nobody has ever put in practice, and it’s a huge leap of faith. It’s never been tried in this area.”

Stone fruit

The Warmerdams participate in Trinity Sales’s preconditioned stone fruit program called RipeWay, and they precondition “everything that’s suitable to be preconditioned,” he said. Preconditioning programs, which follow specific protocols to preripen fruit before shipment, are now becoming standard in the industry, John said.

White-fleshed peaches and nectarines comprise about 40 percent of their peach and nectarine production, he noted, with many of the white-fleshed fruit now being sold domestically as well as in export markets. “It’s rare that white flesh will sell for less than yellow flesh, except for really small sizes, and then they’re hard to get rid of—like trying to move 12-row Rainier cherries.”

Warmerdam patriarch Bill is known within the industry for his innovative ideas in the packing house. Bill devised a color-coded system for workers to use in putting different containers on the packing line’s revolving shelves. He also changed the handling of cherries to reduce damage.

Cherries are now picked in small plastic totes in the field and nestled inside a larger plastic bin for transport to the packing house. The bin full of totes is then dumped at the cherry line, with cherries only dumped once during the picking and handling process.