How to Fight Off ‘Zombie Trees’ on Your Property

Ghosts and goblins aren’t the only thing to fear this Halloween. Dying trees that look healthy can drag a home sale through hell.

Trees can be a huge asset for homeowners, adding up to 20% to a property’s resale value, according to the Arbor Day Foundation’s study, “The Economics of Urban Forestry.” But a dying tree—even one that looks healthy on the outside—can pose threats to the home and be costly to remove. A taller tree can cost up to $2,000 to remove, according to 2023 data from Angi, a home improvement resource. As such, home buyers may want to carefully evaluate the health of a property’s trees before making a purchase; they may even want to include the trees in negotiations.

Michael Spaulding, a district manager at Davey Tree in Portland, Ore., shares the dangers of “zombie trees,” including how to spot them and what to do if one lurks on your property or the one you want to buy.

Q: What is a “zombie” tree?

A: Zombie trees have hidden damages and may appear healthy. However, they are struggling internally due to damage from the previous spring or a prolonged drought. And just like the zombies in a horror movie, they can cause significant damage to the unsuspecting property owner if they’re not on the lookout.

Can they be saved, or are zombie trees doomed?

Zombie trees are a hazard. But unlike their namesake, they don’t have to cause fear and panic. By giving your trees the proper attention and getting the right advice for your tree care questions, they can often be brought back to life. Understanding a tree’s risk level is important. Some defects can be addressed to prolong the life of the tree, and some of this care and maintenance can be done by homeowners. Tree maintenance tips include fertilizing, planting the right trees and shrubs for the local climate and proper pruning.

You mentioned these trees may not show damage right away. How long can it take until it’s obvious?

This can vary by the damage or the age of the tree. Young trees will show signs much more quickly than older trees. Drought, salt and excess water damage can take years to affect the tree on the outside while storm, pest and disease damage could show within a few months.

What are some signs of a zombie tree?

Conduct a home tree health check. Take a walk around the yard and inspect the trees for dead wood or decay, cracks in the bark that extend into the tree’s trunk or limbs, discolored foliage and root and architecture problems. Is the tree lifting on one side or leaning excessively? That could be a sign of trouble. Is there fungus growing from around the base of the tree? That could be a sign of excess water.

When should you call an arborist to take a deeper look?

If you notice any issues during the tree health check, call a certified arborist, who can address problems visible to the naked eye—plus damage lurking inside the tree. Certified arborists have tools to peer into the interior and look at the roots without harming the tree. They can help create a plan of action to restore the tree’s health or have the tree removed. Homeowners should always check for TCIA accreditation, ISA certification, proof of insurance and a list of references when hiring a certified arborist. Hiring an unqualified arborist could cost homeowners in the long run, since it may involve purchasing a costly new tree. If the price sounds too good to be true, it probably is.

Tree removal can be expensive. Should home buyers factor the health of the property’s trees into negotiations?

Yes, we suggest a free landscape inspection from a certified arborist. It takes ground covers, trees, shrubs and irrigation into consideration, giving homeowners the peace of mind that these features have been evaluated by a professional who understands the health and potential issues of these outdoor spaces. The results will give homeowners a clear understanding of the property’s outdoor features and the upkeep and maintenance needed in the near future. A professional will provide potential homeowners with an estimate of the costs they may be facing in the future to repair or maintain their landscape. This can come in handy as a bargaining tool to negotiate over home price.