DENVER (NEXSTAR) — Like so many stale fruitcakes in the last week of December, America’s Christmas trees often find themselves thrown away with the trash in the days following the holiday. Unlike a stale fruitcake, however, discarded trees can serve many useful purposes after reaching their natural expiration dates.

Tim O’Connor, the executive director of the National Christmas Tree Association, said Christmas trees can easily be recycled, repurposed, or donated, and he considers each option much better than simply trashing the tree. “There’s no reason to fill up the landfill with Christmas trees,” he said. “If it ends up in a landfill, it’s taking up that space unnecessarily because it is biodegradable and decomposable.”

“There are so many ways to give the trees a second purpose,” said O’Connor. “Whereas, if it goes into a landfill, it has no other purpose.” He recommended alternatives like composting or mulching the tree. In his neck of the woods just outside of Denver, locals can drop off their trees with the parks department, who converts them to mulch for city or community landscaping.

“The easiest way to find [your city’s tree-recycling options] is by searching online. But the parks department, or public works, or the local trash pick-up services may know where it’s being done, even if they’re not the ones handling it,” O’Connor said. Where he lives, many municipalities or local organizations arrange for pick-up.

Besides mulch, O’Connor said he knew several uses for old trees, include everything from controlling erosion levels to shoring up undersea habitats or reefs. Plenty of zoos, like the Topeka Zoo in Kansas, also give trees to animals to play with.

“You can go online and watch videos of elephants playing with the trees,” O’Connor said. “It’s pretty funny.” Some animals, like goats or elephants, even enjoy snacking on discarded or leftover trees—who knows if they’d feel the same way about crusty old fruitcakes.