Extension Agent Javier Fernandez-Salvador stands next to a three- to four-year-old olive tree planted in the field. He’s experimenting whether olive trees grow better planted in the ground as babies or potted and then transported to the field.
Photo by Aliya Hall

by Aliya Hall

Olive production brings to mind dunking bread into Mediterranean olive oil or rows of trees in California – but now Oregon is positioning itself to be listed among those images.

There are over 50 acres of olives for oil production in Oregon, but that number is rising as more people are becoming interested in olive production, Bogdan Caceu, executive director for the Olive Growers of Oregon and owner of La Creole Orchards, said.

“People come over and talk to me and say ‘I’ve been thinking about olives and I have this many acres,’” he said. “I’ve had at least five to 40 [people] approach and show interest.”

While there is interest in olive growing, Caceu said there is one obstacle getting in the way of growers – and it’s a big one.

“That obstacle is the cold hardiness of olives and the cold temperatures in Oregon,” he said.

The west of the Cascades is famous for its mild winters, Caceu said; however, there are regularly two to four nights of freezing temperatures. During that time, young olive trees under 10 years old can suffer damage that kills them to the ground.

“It doesn’t damage the roots,” Caceu said, “but effectively you’re back down to zero, starting from scratch.”

To help prospective growers, Javier Fernandez-Salvador, Oregon State University’s Marion and Polk County Extension agent, is researching which olive tree cultivars are the most cold-hardy, and attempting to improve propagation techniques. He described the project as his “baby,” and said they are potting the cultivars after propagating and keeping the trees in a greenhouse for the winter.

“We want to make an affordable, small structure for plants before moving them outside,” he said. “We think by potting we’ll get better results. We are trying to transform that into hard data.”

The cost of material for a passive greenhouse tunnel would be around $3,500, but Fernandez-Salvador said it’s one the best solutions to the challenge of keeping one- to two-year-old plants alive during the winter.

The project will also evaluate systems that haven’t been successful in the past, and will therefore be planting small trees in fields as well. For the past few years, however, Oregon has had mild winters and the trees in the field have been surviving.

Fernandez-Salvador said this winter has been another mild one, and he’s hoping that a cold one will happen in the future so they can test their hypothesis of potting versus planting directly into the land, but climate change has made it harder for them to predict. At this point, he hasn’t been able to determine when his trees will start producing because one bad winter will stunt their growth.

Beyond cold hardiness, the team is researching other factors, such as dry farming versus irrigation and flat versus sloped land. All of the fields are organic, and Fernandez-Salvador said they have struggled with rodents in the fields, but weeds are a universal challenge.

“You don’t want weeds to compete with the olive plants,” he said, recommending that adding a weed mat in the field and wood chips in the pot can help with that.

Fernandez-Salvador has also found that olives like a natural soil pH. Pollinator-friendly species planted within the fields are helpful too. Many olive tree farmers have pollinators interspersed in their fields, but they also have pollinators bordering their trees and a line of them running down the middle.

Although it’s a little too early for the university to provide any concrete recommendations, Fernandez-Salvador said his main advice is to start small, have multiple diverse cultivars, do self-propagation and buy sensors that will evaluate the cold pockets in the field.

After this project, Fernandez-Salvador will apply for funding to evaluate the agronomics of olive growing. He said it’s hard to sell these fruits fresh, and milling provides a value-added quality to the crop – a method that has been working well for Paul Durant of Red Ridge Farms, who has Oregon’s only commercial olive oil mill.

Durant’s first trees were planted in 2005, and there are now 130,000 trees across 15 acres. That said, Durant still relies on buying olives from California as Oregon grows their olive yields.

His favorite tree is the Picual, because it survives freezes at 9º and fruits consistently; however, the majority of his crop is Arbequina. He said the distinction and diversity in olive varieties is “wild, as much as grapes,” which he would know, seeing as he also owns Durant Vineyards.

Durant is excited to see the research that OSU does because when he started there was a lot of trial and error due to a lack of information about olive production in Oregon. He said the first question to ask is “Can it survive?” and then “What kind of fruit can it produce?”

“We’re continuing to figure out what trees do well. It’s interesting to see,” he said.

He added that, like the wine he produces, olive oil is a niche product that works best sold directly to the consumer market. Although they have a wholesale presence, selling oil directly off the farm has been where most of their growth has happened.

“That drives more awareness and that’s where the growth will be,” he said. “The food industry here in the Northwest elevates the food experience and connects to growers. It is really limitless in a lot of ways.”

He added that part of it is educating consumers on why the oil tastes different and the quality component behind a $22 bottle of oil.

Durant is hopeful about the future of olive production in Oregon, and is looking forward to more farmers planting trees.

“We were maybe one of three trying this, and now [olive farmers are] bigger in scale. I’m really excited about it and putting energy into it,” he said. “It’d be great if there were other large producers out there to take it to the next level.”