March/April 2023
Almonds in Idaho
The state of Idaho is a lead producer of many major U.S. crops; it leads in potatoes, barley and hay, and is second for sugar beets, hops, onions, wheat and lentils. Tree nut production, however, has rarely been attempted in the Gem State. Sub-zero winter temperatures have long deterred exploring the viability of getting yields from crops, such as almonds and walnuts.
A maturing research study at the University of Idaho, however, may soon change that. Now in their sixth year, almond trees being grown at the Parma Research and Extension Center in Parma, Idaho, are starting to produce yields. And for several of the varieties being tested there, the results are now promising.
Under the direction of Professor Esmaeil Fallahi, the pomology department at the Parma Research and Extension Center studies and attempts to grow a host of “alternative fruits” that may be able to survive in Idaho’s high pH soils. The program has already proven several varieties of table grapes, quince and Asian pears to be quite successful under the right conditions.
Pomologist Michael Kiester, operations manager at the Parma facility, is working on an ongoing study of an acre of almond trees and a half acre of walnut trees being grown to test their viability in Idaho’s tricky intermountain climate.
“We’ve been growing almonds here and there for a while,” said Kiester, “but when a couple rows of Sonora, Monterey and Nonpareils did well, we decided to do more.”
Now with a more sizable test orchard, Kiester and the research team are eagerly awaiting results from the data collected over the past two years. While a couple of the walnut varieties have proved nonviable, so far all of the almonds have fared well.
“No almond varieties we’ve planted here have been lost,” said Kiester.
The USDA rates Parma as being in a zone 6a plant hardiness zone, meaning average minimum temperatures of -10° F to -5° F. But much of Idaho is even colder, in zones 5, 4, and even 3. Kiester says it isn’t uncommon to see a temperature of -30° F sometime during the year. Parma has dry summer heat, up into the 100s but typically in the 80s and 90s, and wet springs. The last frost of the spring is normally before May 10.
Since almonds and walnuts take a while to get established, the trial plot is only now starting to see yields.
“We didn’t really start seeing any yield advantage until the almond trees were five years old, but now we’re seeing some true harvest fields,” said Kiester. “We were seeing some yields in year three, but it wasn’t anything to brag to Mom and Dad about.”
Walnuts can take even longer to get established, and Kiester isn’t expecting to know the results on the walnut trees until at least 2025 or 2026.
“We have some varieties that are surviving and some that aren’t surviving,” he said. “We’re just getting some bare/basic numbers from them at year six, and sometimes it takes walnuts 8-10 years to get a true yield.”
Kiester says there have been several inquiries into the viability of producing almonds in Idaho in past years, both from in-state fruit producers and from California growers who are seeking new opportunities due to California’s water supply issues. The most common questions that growers still have revolve around infrastructure. Harvesting and shelling in Idaho presents a particular challenge, as almonds need to be off the ground before the winter weather hits in September. Idaho-based nut growers would need to make a significant investment in machinery to get the almonds out of the weather and dried, and California- based growers looking to own orchards in Idaho would still need to worry about the costs of transporting the almonds back to California.
Still, the idea of moving into tree nuts is an attractive one for many Idaho fruit growers who see it as an opportunity to save significantly on labor costs. Because nut trees require little pruning compared with other fruits, the savings in that area alone may more than make up for the other additional costs.
It looks like much of the data for the almond and walnut trees in the Parma study is going to come out as a positive indicator for growing potential in Idaho, and if it does, more studies on other tree nuts will likely follow. Kiester said that a few hearty pecan and hazelnut varieties have already been put in, just to see what their potential could be.
Will almond and walnut production in Idaho become a new trend in the next few years? Kiester still isn’t sure, but definitely sees it as a possibility.
“There’s a tremendous amount of interest and the potential is huge, but the potential versus something taking off is a different issue,” he said. “Over the next couple years we will have the answer to these questions.”