Speak for the trees

Avoid these common, unintentional causes of harm

Most homeowners know that trees need water, sunlight and occasional pruning to thrive. But many of the biggest threats to a tree's health come from everyday activities that do unseen damage and make a difference over time.

It’s easy to place focus on visible damage that occurs above ground — the branches, leaves, trunk. But a tree's survival depends just as much on its root system. In fact, many problems begin underground. 

Tree roots need loose, healthy soil with plenty of air, water and nutrients. Activities that disturb or compact that soil can stress a tree long before any signs of decline appear in the canopy.

One of the most common causes of tree stress is soil compaction. As a general rule, avoid disturbing soil under the tree’s canopy whenever possible.

Parking vehicles beneath trees, storing heavy materials in the shade or repeatedly driving equipment across the root zone compresses the soil, squeezing out the air pockets that roots need to survive. Often, home improvement or construction projects are to blame for creating hidden challenges for nearby trees.

Excavating for foundations, patios or utilities can sever roots, while changing the soil grade or repeatedly driving heavy equipment through the area can compress and choke the root system. Before any construction projects begin, create a Tree Protection Zone with temporary fencing, blocking off the area of soil beneath the canopy. This can make the difference between preserving a mature tree and losing it years later.

Root systems should never be disturbed within the Critical Root Zone, ideally giving the tree a diameter of space five times wider than the trunk — or three times wider at an absolute minimum. For example, a tree with a 1-foot diameter trunk would ideally need 5 feet of room, but critically no less than 3 feet. 

Unlike broken branches, the effects underground aren't always immediate. Trees with root damage may not show symptoms until years later, making it difficult to connect the dots to its original cause.

Another common error many homeowners make is allowing grass to grow directly beneath trees — not realizing that grass competes aggressively with trees for water and nutrients. It can also alter soil conditions in ways that aren't ideal for many species.

In nature, trees are surrounded by a thick layer of fallen leaves and organic material that naturally decomposes into rich, healthy soil. This protects roots, retains moisture and slowly returns nutrients to the soil.

Homeowners can recreate some of those benefits by allowing leaves to decompose naturally in landscape beds or by applying mulch beneath trees instead of maintaining grass right up to the trunk.

Mulch rings work best when extended from the tree’s canopy to just before the trunk, tapering off to leave a gap of bare soil around the tree’s base. While the mulch helps retain moisture for the roots, it should never be piled up against a tree’s base, as it can trap moisture against the bark, which is more susceptible to rot. 

Along those same lines, flowers and shrubs may look nice under mature trees, but, like grass, those plants compete with the tree for moisture and nutrients. What’s more, installing those plants often requires digging, which may damage or destroy roots near the surface.

The easiest way to protect a tree is by protecting what's happening underground. When in doubt, give us a call! We’re happy to provide guidance on harm prevention tactics for your trees. 

Lessons from Abroad

Gerlinde and her husband, Ed, toured the streets of Berlin earlier this spring.

Gerlinde Gentzke didn't go to Berlin to study urban forestry. She went to dance.

What she unexpectedly came home with, however, was a notebook full of tree care ideas.

Part of the Smart Feller team since 2020, Gerlinde found inspiration on the streets of Berlin — a city that was completely leveled 80 years ago and remained divided until her own lifetime.

"They took the rubble of their absolutely devastated city and turned it into something beautiful — creating parks, planting trees — with so much thought and effort put into making green spaces last long into the future," she said.

What struck her wasn't just the greenness of the city, though that was immediately apparent. It was the philosophy embedded in how the city treats its trees, its animals, its soil, its water — and its people. "It’s this mentality that if everything in our city is not flourishing, we are not flourishing," she added.

For arborists in Asheville, tree protection zones have become a recurring and somewhat frustrating topic. At its most basic, protection zones provide a barrier that shields a tree and its root system from construction damage. These simple structures are widely understood to be one of the most important tools for preserving mature urban trees.

The City of Asheville is currently developing an Urban Forest Master Plan, and when arborists from across Western North Carolina were brought together to identify the greatest need, the answer was unanimous: protect mature, established trees.

The problem, as Gerlinde has heard over and over again, is that there isn’t room in the budget to protect the city’s trees.

Her experience of Berlin, however, has made that argument hard to sustain.

"Every single little tree in the city has a protection support system on it," she explained. The materials? Bits of corrugated plastic, old drainage pipes, wrapped around the trunk with simple boards placed around it to form a protective box. The boards keep pressure off the trunk, the piping protects the bark, and together they shield the root zone from foot traffic and equipment. "It's a really simple fix, easy to construct, and it repurposes materials that otherwise would end up in a landfill."

There’s no reason we can’t do the same, she added.

In a small sidewalk cutout in the middle of the city, surrounded by a simple two-by-four protection frame, stands a large, healthy horse chestnut tree. A plaque on it reads:

“I am over 120 years old and the oldest horse chestnut tree in Hasenheide. In 1909, I was planted in my youth. I survived two world wars, was not cut down during the Berlin Blockade, but had to sacrifice my roots for gas, water, subway construction and many gas, water, electricity and fiber optic lines, and still suffer more and more from climate change.

“But I suffer and my strength is fading because people and animals urinate on me. Cigarette butts poison my drinking water, and trash is dumped around me. Please show me some respect. Keep me clean, water me and let me live. Thank you.”

A 120-year-old horse chestnut in the middle of the city is protected by a simple wooden frame.

The sign imploring passersby to respect the tree is loosely tied to its trunk with care for its health.

It's a small gesture for the city, but it conveys a powerful message to all who pass by: This tree is not an object. It is a living thing with a history longer than the vast majority of those who enjoy the shade of its branches. It has survived things we cannot imagine. And it is asking for something very simple in return.

Gerlinde knows of several trees in Asheville that could use a sign like that. One of them, near her home in Candler, is a massive, mature white oak tree that survived Hurricane Helene, bears the marks of a lightning strike and recently had its root zone bulldozed during the construction of an adjacent apartment complex. "It's an absolute giant," she said. "When I saw them working in the root zone, I walked up and told the construction crew: This tree is really special; try to be gentle around it."

They agreed to do their best to prevent any further harm. But without legislation to protect our community’s oldest trees, there’s nothing stopping them — or anyone — from causing irreversible damage to these living giants.

Young trees around Berlin are protected by simple support structures like these, made from recycled materials.

Gerlinde came home from Berlin re-inspired about her work with Smart Feller. She and her colleagues already do much of what she observed overseas: creating tree protection zones, proper mulching, keeping organic material on-site — these aren't foreign concepts to the team.

The gap isn't knowledge; it's culture and legislation. The practices arborists have long advocated for are not idealistic or impractical. They exist. They're being used. And they work.

North Carolina currently has no state-level protections for mature trees, and the balance of power has historically favored development interests. But Asheville's Urban Forest Master Plan represents an opening, and Gerlinde wants residents to use it. "I would love to rally citizens to just voice that we want legislation to protect mature trees," she said. The process requires showing up — to meetings, to votes, to conversations with neighbors and developers alike.

For homeowners, the asks are smaller and more immediate: leave your leaf litter where it falls. Resist the urge to "clean up" the forest floor. Water your street trees during dry spells. And if you're planning any construction near a significant tree, call an arborist before the first shovel goes in.

These are not complicated things. A city that was leveled and rebuilt figured it out. “And so can we,” she said.