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DENVER — The definition of a zombie is  “the walking dead.” They look alive, but they are the “undead.”

And that’s exactly what Denver arborist Derek Fox calls trees that look like they are alive and ticking, but they are  prime candidates to be zombie trees.

Zombie tree complex is an insidious and slow death. Trees start to slowly drop their leaves, branches start to decay and if there’s a late diagnosis could mean the tree becomes a total loss.

Zombie complex can happen to any species of tree, shrub or bush.

Bijan Shadlow has been living in his house for 18 years, and confesses his trees need a little TLC, “I would like to keep the tree but I know that it’s diseased,” he said. After an inspection of Shadlow’s landscape, no zombies were found.

Fox says some trees can recover from being a zombie tree, but more times than not they require specialized treatment and pruning.