The Realities of Preserving Mature Trees in New Development

A poorly preserved and protected tree can become an eyesore and a liability.

By Eric R. McQuiston, PLA

Landscape Archictect | Environmental Planner

Mature trees are one of the most cherished elements of any landscape. They anchor neighborhoods, provide shade and comfort and shape the character of a place in a way that new plantings simply cannot match. Because of this, many municipal codes require developers to preserve existing trees and vegetation whenever possible. The intention behind these policies is good. Communities want to protect what makes them feel like home.

These codes reflect a desire to maintain tree canopy, retain familiar neighborhood character and support wildlife that depends on mature vegetation. Birds, insects and small animals benefit from established patterns of shelter and food. On paper, saving existing trees seems like a simple and responsible approach.

But anyone who has watched a construction site evolve knows that the reality is more complicated. Preserving mature trees requires far more than placing a fence around a root zone. Unless a significant amount of care and planning takes place before the first piece of equipment arrives, the results can be unsightly, unsafe and ultimately unhealthy for the tree.

The Hidden Complexity of Mature Trees

A mature tree is not an isolated object. It is the product of decades of conditions that allowed it to flourish:

• Native soils that have never been cut, filled or compacted

• A microclimate formed by surrounding vegetation

• Stable water patterns and drainage

• A wide undisturbed root system

• Protection from wind and temperature extremes

When development begins, most of those conditions disappear. Grading changes drainage. Soil compaction reduces oxygen. Adjacent canopy is removed. Sunlight suddenly reaches areas of the tree never meant to experience it. Even with good intentions, a preserved tree is now living in an environment completely different from the one that created it.

In many cases the tree might survive the construction period, only to begin a slow decline over the next few years. Property owners and developers then inherit the cost of pruning, treatment, monitoring and sometimes removal. What began as a well-intentioned preservation often becomes an ongoing maintenance problem.

Why Code-Mandated Preservation Often Falls Short

Municipal policies assume that keeping a mature tree is automatically a benefit. But without proper evaluation and protection, preservation can lead to:

• Trees that look stressed or misshapen

• Structural instability and limb failure

• Long-term decline and expensive care

• Safety hazards near streets, parking areas and structures

• Reduced storm resistance because root systems and protective canopy layers have been altered

• Legal liability for property owners and developers if a declining preserved tree causes damage or injury

  
  

These last points are often overlooked. A tree that once stood safely for decades can become vulnerable after the surrounding environment is changed. Root loss, soil compaction, altered wind exposure and changes to water patterns can undermine the stability of even a large, healthy tree. In storm-prone regions, a stressed tree may no longer withstand high winds the way it once did.

From a legal standpoint, property owners and developers may be held responsible when a preserved tree fails. If the tree was knowingly retained in a compromised condition, or if proper assessments were not performed, liability exposure increases. What seemed like a preservation success on paper can quickly become a source of risk.

The Essential Role of a Consulting Arborist

Tree preservation succeeds when it begins early. A consulting arborist can identify which trees have genuine long-term potential and which do not. They can inspect structural integrity, determine root-zone limits, recommend protective measures and work with the design team to adjust plans around viable trees.

The arborist’s input is most effective when it shapes the site plan before it is finalized. By the time construction begins, the window for meaningful preservation is already closing.

Unfortunately, arborists are often brought in too late—after the site is cleared, after grading has begun or after the tree is already in decline. At that stage, there are few good options left, and liability concerns become even more pronounced.

When Removal and Replacement Is the More Responsible Path

This is a point I share often with clients, developers and property owners: preserving unhealthy or marginal trees does not serve anyone in the long run. A new development creates a new environment. If a mature tree cannot adapt to that environment, then removing it and replanting appropriate species may be the better choice.

New trees can be selected for site conditions, spacing, structural strength and long-term health. They establish naturally within the post-development environment. Under the right maintenance regime, they grow predictably and become strong contributors to the future canopy.

Most importantly, new plantings avoid the hidden risks associated with compromised trees; risks related to storm failure, structural instability and the legal exposure that comes with them.

A Balanced View

Tree preservation requirements were written with the best of intentions. They reflect genuine community values. But good intentions must be paired with realistic expectations and proper expertise. Without early planning and arborist involvement, preserved trees often struggle. The result can be disappointing to property owners, problematic for developers and potentially hazardous to the surrounding environment.

A balanced approach acknowledges that the goal is not to protect trees at all costs, but to create landscapes that will thrive for decades. Sometimes that means preserving truly viable mature trees. Other times, it means letting go of what once worked and planting anew with confidence and vision.

Either way, the goal remains the same: strong, healthy landscapes that serve the people who live, work and invest in them.

Ready to Plan Your Next Project Wisely?

If you are a property owner or developer facing decisions about tree preservation, landscape planning or site design, I can help you evaluate your options with clarity and experience. Thoughtful landscape planning begins long before construction starts, and the right guidance can save time, reduce risk and create healthier long-term results—both visually and legally.

Visit www.ericrmcquistonllc.com or reach out directly if you would like to discuss your project, explore consulting services or simply ask a question. I am always glad to help you make informed, confident decisions about the landscape you are creating.

~Eric