PUYALLUP, Wash. — Vacuuming dry pine needles off the carpet is an inevitable part of having a live Christmas tree — or is it? Washington State University Plant Pathologist Gary Chastagner and Geneticist Ulrik Nielsen have been working to develop better-quality Christmas trees that won’t dry up and shed their needles.

Nielsen, a researcher at the Forest and Landscape Research Institute in Denmark, and Chastagner are working on several projects to find Christmas trees with superior moisture retention through a WSU/Danish cooperative project supported by the USDA/Danish Christmas Tree Grower Association.

“One of our major efforts is improving the quality of trees available to consumers,” Chastagner said. “That is why post-harvest research is very important.”

Through the project, the researchers have found that some clones of the Nordmann fir, which is commonly grown for Christmas trees, have better water retention after harvest than the original fir. The seed from these superior trees in Denmark was harvested and imported for Pacific Northwest growers.

It was also found that noble and Fraser firs were the only species that consistently did not have needle shedding and discoloration when displayed dry, and displaying them in water was an effective way to maintain moisture retention at a minimum of three to four weeks.

Chastagner and other WSU researchers are also working on development and testing of preservatives that help trees retain moisture and minimize fire hazards.

For more information about Christmas trees, contact Chastagner at the WSU Puyallup Research and Extension Center, 253/445-4528.