Kendra Pierre-Louis: For Scientific American’s Science Shortly, I’m Kendra Pierre-Louis, in for Rachel Feltman.
The Christmas tree appears like a practice from time immemorial—and in some methods it’s. Historians hint using evergreens in winter festivals way back to historic Egypt and Rome. However the trendy American customized has newer roots: to the 1800s and German immigrants in Pennsylvania. These immigrants are believed to have introduced the observe to their new house within the U.S.
The tree customized gained much more traction when it appeared in an tailored sketch of Queen Victoria and her German-born husband and their kids that was printed in a U.S. ladies’s journal. Many credit score it with kicking off a development that has endured to at this time.
On supporting science journalism
For those who’re having fun with this text, take into account supporting our award-winning journalism by subscribing. By buying a subscription you might be serving to to make sure the way forward for impactful tales concerning the discoveries and concepts shaping our world at this time.
And whereas quite a few folks in recent times have opted for lower-maintenance artificial timber, many revelers nonetheless desire the look and scent of actual timber. However due to local weather change pure Christmas timber and their followers are dealing with new threats.
In the present day we discuss to Priya Rajarapu, an assistant professor and Christmas tree extension specialist at Oregon State College, concerning the dangers tree growers are weathering and what, if something, could be carried out.
So, Priya, what precisely do you do?
Priya Rajarapu: [The] most easiest method I might clarify is: when you find yourself sick you name a health care provider, and when Christmas timber are sick growers often attain out to me.
Pierre-Louis: What sorts of timber are Christmas timber, and the way are they usually grown?
Rajarapu: So Christmas timber are all often fir timber or evergreens, and there’s a historical past behind it. Evergreens are inclined to hold their needles all through the season. So it’s a symbolism of hope, so Christmas is often celebrated round that. It’s additionally trying ahead to the spring and harvest season.
And Christmas timber, though they’re evergreens that you just see principally in forests, they’re an essential agricultural commodity within the U.S. We promote [roughly] 14 million Christmas timber, as of 2022 survey within the U.S. …
Pierre-Louis: Wow.
Rajarapu: And the 4 main Christmas-tree-producing states embody Oregon, North Carolina, Washington and Michigan.
Pierre-Louis: So we actually are speaking a few farmed product, and I don’t assume most individuals usually image Christmas timber the identical approach that we consider, say, corn or potatoes. What makes a farmed tree completely different from the timber that I see within the forest?
Rajarapu: Yeah, I’m glad you talked about the corn and potato analogy as a result of that’s one of the simplest ways to view Christmas timber, too, is that they’re grown much like corn and potatoes or every other vegetable crops. It’s simply that it’s a specialty crop—it’s a tree, so it has an extended rotation. So corn, you may get a crop in an ear …
Pierre-Louis: Mm-hmm.
Rajarapu: However Christmas tree, you’re harvesting the tree. Then you need to wait wherever, relying on the species, from 5 to 10 years to reap a tree.
And the distinction between the timber which might be grown on farm and the timber that develop within the forest is that the timber which might be grown [in] the farm are cultured …
Pierre-Louis: Mm-hmm.
Rajarapu: Which means they’re pruned to provide you that good Christmas tree form, the everyday triangle form that you just see. So growers make investments plenty of time in culturing and pruning the timber so the timber can turn out to be bushier and fuller for folks to hold extra ornaments and never see the stem or department.
Pierre-Louis: To form of keep away from the unhappy Charlie Brown Christmas tree.
Rajarapu: Just about …
Pierre-Louis: [Laughs.]
Rajarapu: However there are—there’s a buyer base who nonetheless likes Charlie Brown Christmas timber, so there’s a fairly decent-sized client base for pure timber or natural-looking timber.
Pierre-Louis: One of many components of the work that you just do is type of trying on the pressures of local weather change on tree manufacturing. And so what sorts of pressures are you seeing?
Rajarapu: So I might say the altering temperatures and lesser precipitation. So we’re getting increasingly more days with much less precipitation, so there are years the place there isn’t any precipitation for 100 days in Pacific Northwest, which does pose plenty of problem for protecting timber wholesome and likewise seedlings alive.
So for each Christmas tree that’s lower there’s at the very least one other two seedlings which might be going again within the floor. So it, it’s a [roughly] 10-year rotation, so grower has to maintain his crop going, so she or he vegetation timber yearly within the floor, and that first 12 months of progress or seedling institution after transplanting them into the sphere or farm could be very essential. So when there’s drought or when there’s greater temperatures and lesser precipitation, it’s arduous for that specific seedling to remain alive and set up itself. In order that is among the key challenges that growers are seeing with the altering climate patterns.
And likewise, one other change that I’ve seen is [the] kind of web site that you just select on your species also can stress the timber and might appeal to bugs comparable to bark beetles or twig weevils that have been occasional pests—now their frequency is growing.
Pierre-Louis: As a result of the local weather is getting hotter?
Rajarapu: Yeah, due to the hotter local weather and likewise lesser precipitation or no precipitation in Pacific Northwest. I’ve been in North Carolina, and it rains lots. There, flooding is a matter. However in Pacific Northwest in summer time, it’s dry.
Pierre-Louis: And that’s not regular, proper? Like, up to now you wouldn’t get 100 days with out rain.
Rajarapu: Appropriate. What I hear from growers is that it will rain till July Fourth …
Pierre-Louis: Mm-hmm.
Rajarapu: It might, like, continuously rain, with none break. So the one time that they go with none precipitation is August and September, after which October it begins raining once more. So it’s simply the 2 months, which, usually, soil would maintain sufficient moisture throughout that point.
Pierre-Louis: However now it’s prolonged to, like, 100 days, and the soil simply can’t maintain moisture for that lengthy.
Rajarapu: Precisely, that’s what we’re seeing. And proper now I’ve an experiment that’s going within the area the place I’m making an attempt to observe the moisture current within the soil all through the rising season and take a look at completely different mulch overlaying the seedling in order that I might enhance that moisture retention within the soil by mulching the seedling, defending that moisture within the soil from evaporating.
Pierre-Louis: And I do know it’s nonetheless early, however are you seeing any type of promising outcomes, any ideas of issues that may assist scale back the influence of these pressures on the seedlings?
Rajarapu: Yeah, positive, so the mulching observe or experiments to enhance seedling survival; it’s not one thing new …
So seedling survival—that first 12 months of multinational could be very essential. It has simply turn out to be in order that, with the climate patterns, it has turn out to be more difficult. So a few of the issues that my predecessor and different professors at Michigan State College have tried is completely different root dips, so these are polymers, these are inert polymers that cowl the foundation floor and are business merchandise which might be obtainable and are claimed to carry moisture and likewise any vitamin.
So all these trials have been carried out up to now, and what got here out or emerged as a hero or a savior is mulch. Simply typical wooden mulch would assist seedlings survive and likewise considerably scale back the temperature—that’s, soil temperature—below the mulch. However one of many issues that growers have is that the wooden mulch, relying on the supply the place they’re getting from, may carry some illnesses that may infect their soil. However we don’t have any proof, scientifically, for that. That’s one of many issues they’ve.
And it’s additionally the worth. Like, if wooden mulch is dear, is there one thing that we’re getting without spending a dime? For instance, this 12 months three or 4 completely different mulch covers that I’m making an attempt is sawdust, compost, and I’ve tried hazelnut shells. Hazelnut is one other huge trade in Oregon, and all of the hazelnut growers are questioning what to do with their shells after they harvest the nuts. So they’re looking for ways in which they might reuse or repurpose these shells, so I’m testing that, additionally, as a mulch on this area trial.
And proper now my outcomes present any form of mulch would assist the seedling survive higher than having no mulch. However I’m finding out extra deeper into this, so I’m measuring needle chemistry to see if there’s any distinction in vitamin from these completely different mulch. That’s one other concern for growers, too, that these uncooked, uncomposted mulch may steal nutrient from the soil and, additionally, a seedling may not be getting sufficient. In order that’s one other concern that I’m making an attempt to handle with this analysis.
Pierre-Louis: One of many methods tree farmers are dealing with growing pressures round local weather change is by planting some completely different species of timber. I perceive they’re perhaps planting some timber that got here initially got here from Europe?
Rajarapu: Yep, so we, at OSU Extension, and likewise North Carolina State has a really robust Christmas-tree-genetics program. So again in 2010 researchers from Oregon State College and North Carolina State College and Washington State and Michigan State acquired collectively and went to Republic of Georgia and Turkey to search out completely different species that may maintain their needles nicely, could make different nice Christmas timber …
Pierre-Louis: Mm-hmm.
Rajarapu: And regarded for these timber. So that they collected seeds from timber which have nice traits or that may make nice Christmas timber. They introduced in these seeds, and so they grew all these seeds, two seedlings within the U.S. …
Pierre-Louis: Mm-hmm.
Rajarapu: And planted in several areas throughout the U.S. So we’ve got these trials, or check plots, in Washington, Oregon, North Carolina, Michigan, Connecticut, Pennsylvania. So all the identical seedlings have been planted in several areas to see if sure seedlings would emerge as good for that geographic situation.
So we discovered some that carry out greatest in Oregon and Washington, and we’ve got established seed orchards for the seedlings, or explicit genetics, for Nordmann and Turkish fir. These are the 2 firs that we recognized or have been introduced into the U.S. as seeds, and we’re rising them in order that they will mature and produce seeds. And sure, these appear to do higher than our natives, like noble fir, significantly, which could be very delicate to temperature adjustments and lesser precipitation, whereas these Nordmann and Turkish fir have been extra resilient, and likewise, they don’t appeal to plenty of pests that [are] usually [attracted to] the native timber. And likewise, they’ve excessive tolerance for several types of soil. So these traits are making them in style.
Pierre-Louis: So for the one that loves a reside Christmas tree how involved ought to they be that, sooner or later, it may not be accessible?
Rajarapu: To date growers are working actually arduous to maintain the availability going. There may be positively a lower within the variety of acres in manufacturing of Christmas timber.
We’re seeing that it is perhaps value that is perhaps driving some folks to, like, change their thoughts. So synthetic Christmas tree, it’s comfort and likewise the worth. It’s, like, you’re paying $400 for 10 years. I believe all of it involves that.
We try actually arduous to maintain the variety of timber, the reside timber, accessible to all shoppers. We often have extra timber than we’ve got shoppers, so I don’t assume so …
Pierre-Louis: Oh, wow.
Rajarapu: Having a scarcity can be an issue, so long as shoppers are prepared to purchase the timber.
Pierre-Louis: That’s actually cool. It’s been beautiful studying a lot about Christmas timber with you. Thanks a lot for taking the time to talk with us at this time.
Rajarapu: Certain, Kendra.
Pierre-Louis: That’s all for at this time! We’re taking a little bit of a break for the vacations and can be again with recent episodes in 2026. Within the meantime we’ll be revisiting a few of our favourite episodes of 2025, so be certain that to test these out subsequent week.
Science Shortly is produced by me, Kendra Pierre-Louis, together with Fonda Mwangi, Sushmita Pathak and Jeff DelViscio. Shayna Posses and Aaron Shattuck fact-check our present. Our theme music was composed by Dominic Smith. Subscribe to Scientific American for extra up-to-date and in-depth science information.
For Scientific American, that is Kendra Pierre-Louis. See you subsequent time!
