Are Trees Hurting or Helping Your Listing?

Certified arborist John Palmer reveals the benefits and drawbacks of a home’s landscaping that both buyers and sellers need to keep in mind.

You probably don’t think much about the trees on a home’s property unless they pose an immediate threat to the structure. But you may not be aware of how much value trees hold and how they can affect the price of your listing. John Palmer, an arborist who is certified by the International Society of Arboriculture, reveals the true benefits and liabilities of trees, what buyers should look for in home landscaping, and what sellers can do to protect the value of their trees.

Can trees actually affect the property value of a home?

Each mature tree in the landscaping of a home has the potential to increase property value. (The U.S. Forest Service’s Pacific Northwest Research Station says the planting of a tree in the front yard increases a home’s value by an average of $7,130.) Studies have found that one surprising benefit of trees is that neighborhoods with greater tree canopy have lower crime rates—which has a direct impact on property values. But think about this: When a tree is on the south or southwest side of a house, it shades the home in summer, provides a wind screen, reduces temperatures, and lowers cooling costs. When a tree sheds its leaves in winter, there’s more sunlight on the house. That translates to real value where home energy costs are concerned. If you want to know the value a particular tree adds to your property, you can go to the National Tree Benefit Calculator and plug in the species and size of the tree and your ZIP code. For example, the calculator shows that in the Midwest, an elm tree 30 inches in diameter provides $345 in annual benefits to a homeowner.

Are there myths that buyers and sellers believe about trees?

Some people are scared of trees—especially big ones—falling onto their house. But that’s about as likely as an airplane crash: It makes headlines, but realistically, it doesn’t happen very often. Trees can fall when their root systems are compromised by decay, or, if there are many days of rain, extreme wind events can cause the roots to pull out of the lubricated soil. People also think trees damage sewers, but generally, trees don’t create the problem. If a 75-year-old drainage system starts to break down, the tree roots will go where the moisture is. If the system is intact, a tree is far less likely to bother it. Another thing to be aware of is not to compact the soil around a tree. The roots absorb oxygen from the soil and give off carbon dioxide. So if the soil is compacted too densely without room for air or water space, it can cause the tree’s health to decline, making it more susceptible to other risk factors. That’s why it’s important not to compact the soil, say, by driving a vehicle on it.

What should home sellers know about their trees before listing?

They can contact a certified arborist—ask if they have attained the Tree Risk Assessment Qualification—who can provide a report attesting to their trees’ health. Recently, one of my customers decided it was time to move, since she’s now an empty nester. She had a glorious 200-year-old bur oak. I wrote an assessment of the tree and gave it a clean bill of health, citing a well-developed root flare and no dieback in the branching. The homeowner and her real estate agent said the letter helped put potential buyers at ease; they think it helped speed up the selling process.

What tree maintenance practices should homeowners follow?

You should have the dead wood taken out so you don’t have a branch drop on your roof or garage. The best time to evaluate the structure of a tree is after the leaves have fallen because you can see the branching more clearly. The single most important thing you can do is water a tree, especially if there’s been no rain for a couple weeks. Just put the hose on a slow trickle at the base of the tree, go in and make dinner, and then come turn it off. For more advice, check out the Tree Owner’s Manual from the U.S. Department of Agriculture.

What signs of tree problems should buyers and sellers be aware of?

Monitor dead or dying branches and mushrooms on the trunk, which indicates decay. However, some things might look scary but actually aren’t. Maple tar fungus causes big black spots on the leaves. It can appear during humid conditions, but it’s purely cosmetic. It looks bad, but it’s not going to harm the tree. On the other hand, some things might look nice that are actually damaging. Piling a volcano of mulch around the base of the trunk is extremely bad for trees. Roots grow upward into the mulch and can start to choke each other. Lay on no more than two inches of mulch, and don’t let it touch the trunk. Trunks are meant to be dry; roots are meant to be wet.

How does a homeowner know when a tree should come down?

Firstly, don’t rely on your own personal assessment. That’s what professionals are for. Basically, you’re looking for decay: cavities, holes, and branches that are splitting or cracking. If a tree hasn’t grown leaves in a year, it may have to come down. What I look for is the target: What will it hit if it falls? If it’s in a backyard where there’s no target, it’s generally not a problem. But the same tree in a different scenario might be a risk. If an old, decaying tree is right on a corner lot across from a school where kids are walking every day, it becomes a high-risk tree.

Are there trees that actually are less valuable because of their placement on property?

You can put a tree in a place where you’re not getting the benefits. If you plant a big tree on the north side of your house, it’s your neighbor to the north who gets the shade.

How do you know who’s responsible for a tree that spills over onto the neighbor’s property?

If the tree trunk is on your neighbor’s property and a branch falls in your yard, it’s your responsibility to clean it up. And vice versa. You can legally trim tree branches that overhang your property, but you need to make sure you don’t damage the tree or cause structural instability, or you could be liable for monetary damages. Laws on this vary from state to state.

What other advice can a real estate professional give a new homeowner?

I think one of the first things you should do when you buy a new home is plant a tree, because it needs time to grow. When it comes time to sell again, the bigger the tree, the more valuable it is. But remember that when you plant a tree, you have to think about the mature size of the tree. Placement is crucial. You don’t want to put a big evergreen six feet from your foundation. If you’re not sure, get a professional assessment.