Oregon is the leading producer of Christmas trees in the nation, accounting for about a third of all real Christmas trees sold in the U.S. Christmas tree farmers in Oregon grew more than 3 million Noble fir, Douglas fir and other Christmas tree varieties in 2023, the most recent year for which statistics are available.
Priya Rajarapu is an assistant professor in the college of forestry at OSU and the Christmas tree specialist at OSU Extension Service. In the past year, she has visited 20 Christmas tree farms in Oregon where she has offered advice, diagnosed diseased trees and confirmed infestations of bark beetles and other pests.
But the biggest threat Oregon’s roughly $120 million Christmas tree industry faces is climate change, according to Rajarapu. Extreme heat and drought can imperil the survival of Christmas trees, especially seedlings. Rajarapu has been studying mulch alternatives like compost that has been shown to boost the survival of seedlings during their first year.
Rajarapu joins us for more details about her work and why non-native varieties such as Nordmann and Turkish firs are gaining in popularity among both farmers and consumers.
Note: The following transcript was transcribed digitally and validated for accuracy, readability and formatting by an OPB volunteer.
Dave Miller: This is Think Out Loud on OPB. I’m Dave Miller. “If you’re sick, you call a doctor.” My next guest has said, “If you’re a Christmas tree grower who has a sick tree, you call me.” Priya Rajarapu is an assistant professor in the College of Forestry at OSU and the Christmas tree specialist at OSU Extension Service. It’s her job to support Oregon’s Christmas tree industry, the largest in the nation, through research about disease, pests, and growing techniques. She joins us now to talk about all of this along with advice for how to keep a cut tree looking its best for as long as possible. Priya Rajarapu, welcome to Think Out Loud.
Priya Rajarapu: Thanks for having me, Dave, and for a great introduction.
Miller: What makes Oregon the number one Christmas tree producer in the country?
Rajarapu: So, Oregon, we grow Noble fir and Douglas fir. Those are the more popular, most popular Christmas trees, and they are native to Oregon because of the weather. We have the wettest winters and mild summers, which makes more, the weather more conducive for trees to grow their best.
Miller: What is this year’s harvest looking like so far?
Rajarapu: We don’t have statistics, so ODA runs a survey every two years to know the statistics on the harvest, and number of trees that have been grown, and how many were planted, how much did we make in revenue as a state, but I do have statistics from ‘23. We sold, so in 2022, we sold about 3 million trees, which accounted for $118 million in sales. And Noble and Douglas fir are the most popular and the most sold trees in 2022. And I’m curious to see what the trend is going to be this year.
Miller: Where do Oregon’s trees end up, in our country or around the world?
Rajarapu: They end up everywhere, in every corner of the world, but we are major exporters, so 50% of our trees go to California and Mexico, Hawaii, but we also have other international importers like Asian countries, Japan, Hong Kong, Indonesia, Malaysia, and Dubai is our newer country that imported Oregon trees. And Canada.
Miller: In Dubai, I mean, I don’t suppose you’re following the trees to see where they end up, but are these like in commercial places or like an airport or a fancy hotel, or do people have them in their homes as well?
Rajarapu: That’s a question that I asked a grower too who was selling, who was ready to ship a 16 to 20 ft. tree to Singapore, and what he told me was that they display it in a commercial place like outside a mall, [and] decorate them during holidays.
Miller: The internationalization of a sort of a northern tradition now all over the world, including in places that are not classically Christian countries, it’s just, it is a globalization of a particular way to celebrate a particular religious holiday. You started, as I understand this, your current job about a year ago. Is it true that you actually started working on Christmas Eve last year?
Rajarapu: Well, I, yeah, I thought it’s gonna be cool to have a start date, to have Christmas Eve, but I’ve been thinking about the issues of the industry, even before I joined, trying to learn more about the industry because I worked at North Carolina State University Christmas Tree Genetics Program before I became Christmas tree specialist for the state. And the two geographic regions are so different and the species we grow is very different. So I was trying to understand the differences between both the industries.
Miller: Right. As I understand it, North Carolina is the #2 producer of Christmas trees in the U.S. Did folks there, when you said, “I’m jumping ship and I’m going to Oregon”, did they see you as going to their rival?
Rajarapu: They were, no, they said, the best comment that I heard from a grower was that they’re going to truly miss me, but they are happy to see me do good things and great things in the Pacific Northwest.
Miller: What are some of the most common issues that Oregon producers come to you for help with these days?
Rajarapu: One of the most common issues I got or received calls or I’ve, during informal surveys, I’ve heard is seedling survival. That’s because, again, with climate change, the first year planting of the seedlings, the newly transplanted seedlings suffer the first summers or extended period of drought without any precipitation and hot weather. And that has been a challenge to most of the growers. But other than that, I’ve also received calls of different insects, such as bark beetles, which are known to infest stressed trees, and I’ve received a call and I identified a bark beetle in a Christmas tree farm, which is quite unusual for Christmas trees, which are grown as an agriculture crop.
Miller: Huh. Normally, bark beetles would, they would infect older trees in the forest as opposed to a farm with younger trees?
Rajarapu: Yeah, so bark beetles have this ability to sense the scent of a tree, and they are more attracted to a tree when they are stressed, because it’s pretty much like when we weaken our immune system, we are more susceptible to pick up a disease or sickness. It’s the same thing with trees, is when they are stressed, the defenses are allocated to a different part of their physiological system. So tree, and insects can sense that, so they attack stress trees.
Miller: So pest pressures are changing as a direct result of climate change.
Rajarapu: Correct.
Miller: What can you tell Christmas tree growers to, if they come to you and say, hey, you know, we have this infestation or we’re having new problems because of drier seasons, hotter summers, what help can you provide?
Rajarapu: So there are two things I suggest. The first thing is site selection, so not every species can be grown everywhere. So, Noble fir, for example, is adapted to higher elevations of about 3000 ft, and it grows, it’s naturally found between 3000 to 5500ft. So, finding the right species for the site where the farm is would be the best way to grow healthy trees. But still, there are some Noble fir, which through OSU extension and my predecessor Chal Landgren has done some studies and planted Noble fir genetics through different areas in Oregon. So, we have some genetics that do well at lower elevations too.
And they would do good with some help like mulching the seeds, the seedlings. So we have found, Chal has found that wood mulch would improve seedling survival, and I’m continuing that research to find alternative mulch options. So I’m trying hazelnut shells, compost and sawdust. Sawdust is being actively used by some growers to keep seedlings alive, and they’re seeing greater success.
So I’m continuing to do research and collect different parameters to see which works best as a mulch. In addition to that, also, we have new species, such as Turkish fir and Norman fir, which are known to be more resilient to a wide range of climate and that we have, so that’s another suggestion I give to growers is to plant climate resilient species in the sites that, where you can’t grow Noble fir.
Miller: I’m talking right now with Priya Rajarapu. She is an assistant professor in the College of Forestry at OSU and the Christmas tree specialist at OSU Extension Service. Am I right that the Norman and Turkish firs have been, that people have been exploring their use, their growth in Oregon for about 25 years?
Rajarapu: I would say, I would say so, yeah.
Miller: Has there been any pushback? I mean, as you noted, there are these iconic native species, Doug fir on the state license plate, Noble firs, beloved for smelling a little bit more like a sort of a classic Christmas tree smell to some people. So these are these native species, and then now we’ve had these others from Eurasia. Is anyone saying we don’t want these introduced trees, we want the natives?
Rajarapu: Not yet, not yet, because these trees still belong to true Firs, and they look beautiful. They make great Christmas trees, and again, these have been selected for their Christmas tree traits, and they don’t have, they’re not known to have a lot of insect pest issues, so they are also not chemically managed as much as Noble firs or Douglas firs. But we didn’t see… And for example, I have the numbers, we sold like around 258,000 Norman and Turkish firs in 2022. So there is a market for these firs, and they do look amazing, so there is no pushback. And also in a public event, when I display the boughs from Noble fir, Douglas fir, Turkish fir, and Norman fir without kind of giving a blind choice to people, they are inclined towards Noble fir that they’re familiar with, but there’s also people who like Turkish fir, just the way it looks, how the needles feel.
Miller: How did you become a Christmas tree specialist?
Rajarapu: So, I used to be, I’m an entomologist, with, again, a broad set of expertise in biochemistry and molecular biology, and my interests have been to study how insects become pests. So, I was working with invasive insects like Emerald Ash borer, which is, again, an invasive insect here in Oregon. So I did that for my PhD and then I got an opportunity to study another invasive insect in Frasier fir, which is the most popular Christmas trees in North Carolina. So I wrote a grant with my collaborator and friend, Justin Whitehill, and it got funded and I got inducted into the Christmas tree industry, and this position opened. So that’s how I’m in the Christmas tree industry.
Miller: Did your family celebrate Christmas when you were growing up?
Rajarapu: Yes, we did.
Miller: Did you have a Christmas tree?
Rajarapu: I want to put India on the export market, and ship Christmas trees from here. No, we did not have a Christmas tree, sadly, a real tree, but I had families where they did display artificial trees in India.
Miller: Has being in this role for a number of years now, has it changed your perspective on Christmas as a holiday?
Rajarapu: I have attended convent school growing up, so it was never a different or a new concept for me. So my perspective hasn’t changed, but I feel lucky that something that I, a festival that I grew up with, and I enjoy like helping the industry, it just feels like I closed the circle.
Miller: What advice do you have for folks maybe right now who have trees in their homes, and they want those trees to look as good as possible for as long as possible. What should they do and also what should they not do?
Rajarapu: So, I would like to give the analogy of cut flowers. So, it’s the same thing that you do for cut flowers. You do the same thing with a cut Christmas tree. Water. Water the tree. The tree, when it’s fresh, when you get the fresh cut tree absorbs a lot of water, it just sucks up everything in the first few days. So make sure you water the tree, make sure you buy a stand that can hold the water. But again, if you’re getting a Noble fir, a research from Washington State University by Gary Chestagner has shown that Noble fir can be displayed for 4 to 6 weeks without water, and it wouldn’t drop any needles.
But if you want Norman and Turkish fir, you can display it for 4 to 6 weeks, but you gotta water those trees, and also the water doesn’t need any additional supplements like sugar or the most interesting one that I’ve heard is vodka. Save your vodkas. Don’t put that through the tree, just water would work. And also, yeah, I think those are the two things that I would say, just water it and all that tree needs is water to display it for a longer time.
Miller: Have tariffs or trade uncertainty been affecting tree growers?
Rajarapu: I am not familiar with that, but we don’t import a lot of trees. We export them. So we really, I didn’t hear any concerns from the growers about tariffs.
Miller: Finally, what kind of tree do you have this year?
Rajarapu: Noble fir.
Miller: Noble fir, sticking with the classic.
Rajarapu: Sticking with the classic, but I would like to try different species, for a personal experience on how it looks, displaying different species.
Miller: Priya Rajarapu, thanks so much.
Rajarapu: Thank you.
Miller: Priya Rajarapu is an assistant professor in the College of Forestry at Oregon State University and the Christmas tree specialist at OSU Extension Service.
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