Viagra Won't Help Your Christmas Tree Stand Up. Photo credit: Getty Images.

People really go to great lengths to keep their Christmas trees fresh and erect. Perhaps that's why some dissolve a Viagra tablet into the tree's water dish. The hope is that the little, blue erectile dysfunction pill will help the tree stand up (way up) for longer.

Does it work? Not if you want your tree to last more than four hours, said Jim Waters, the executive director of the Catskill Forest Association in upstate New York.

"This is ridiculous and expensive. It does nothing for your tree," Waters said.

The TV show "Myth Busters" came to the same conclusion, more or less. In a recent episode, "Myth Busters" found that adding a bit of "Santa's Little Helper" did allow the tree to hold on to its needles a little longer than water alone, but it also made the tree look sickly.

Waters said other common additives such as aspirin, bleach and lemon-lime soda were also as pointless as the needles on a plastic Christmas tree. None of them will prolong the life of a tree because, as Waters pointed out, it's already dead.

The only way to delay the inevitable rain of dry brown needles onto your carpet is to cut one inch off the bottom of the tree and place it in water immediately after bringing it home.

"You have to be vigilant with it and keep the water bowl full all the times," he explained. "If it dries up for even half an hour, the tree will seal itself off and dry out very quickly."

The water doesn't have to be the fancy bottled variety either. Plain old tap water is best, Waters said.

With proper care, most trees will last two to three weeks, though Waters said the time frame would vary depending upon how long ago the tree was cut before it was sold.

Type of tree can also make a difference. In general, firs last longer than spruces. The former has soft, flat needles while the latter has sharp needles and branches.