"I’m not particularly worried about it … I’ll just sweep it up," said Lisa Smith-Hansford of
New York, who bought a small tree at a Manhattan sidewalk stand early this week. She likes the smell of
a real tree, she said, comparing it to comfort food.

But others do mind. Consumers consistently cite messiness as one of the most common reasons they don’t
have a real tree, says the National Christmas Tree Association.

Keeping a tree well-watered goes a long way toward minimizing the needle problem. But beyond that,
scientists are trying to find ways to make trees less messy and keep them fresh through the holidays.

IT’S IN THE GENES

Some kinds of trees, like the noble fir or Fraser fir, are better than others at maintaining moisture and
keeping their needles once they’re in your house, says Gary Chastagner of Washington State University.
But even within a given species, some trees are better than others, he said. Needle retention is an
inherited trait: if a tree does well, so will the offspring that grow from the seeds in its cones.

SEEKING THE CHAMPS

At a research station in Puyallup, Washington, Chastagner works to identify individual trees that hold
onto their needles best. He tests branches cut early in the fall, which encourages needle loss because
they haven’t experienced cold weather. He lets them dry out and his team evaluates them after about 10
days, looking for branches that do not shed any needles. Needles start to fall off branches from some
trees within three to five days when the branch is gently rubbed, even if they aren’t dry and brittle. A
poor performer may lose all of them within a week.

GOOD BRANCH IS GOOD SIGN

If a branch does well, it means the tree has good genetics for keeping needles. So growers can seek out
seeds from those trees to produce seedlings for future planting. These progeny should do well, too. With
a federal grant, Chastagner is also working with others to identify genetic markers that indicate
whether a tree will resist needle shedding. That would make the tree-screening process much faster and
perhaps lead to breeding experiments to produce superior trees.

ANOTHER GLOBAL WARMING WORRY

Trees that experience warm autumns tend to have more needle loss later, Chastagner said. So if global
warming leads to warmer falls in the future, it could be bad news for Christmas trees, he said. But
since his studies focus on tree branches harvested before cold autumn weather sets in, they may identify
trees that will do well in a warming world, he said.

FOR NOW, WATER THAT TREE

Chastagner emphasizes that homeowners can minimize needle shedding by keeping their displayed trees
well-supplied with water. In fact, when he has set up trees for research in early December and kept them
watered, some species, like noble and Nordmann fir, have gone even three months with only minimal
shedding. "The potential is phenomenal," he said.

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Malcolm Ritter can be followed at http://www.twitter.com/malcolmritter