Mature trees can be one of the most valuable assets on a commercial property. They provide immediate visual impact, shade, screening, and a sense of permanence that newly planted trees can take years to achieve. For developers, preserving existing mature and heritage trees can also be an important part of meeting local landscape and tree conservation requirements.

Raleigh’s Unified Development Ordinance (UDO) specifically recognizes the value of preserving mature trees and existing vegetation. Its tree conservation regulations are intended to preserve tree coverage, mature trees, and natural resource buffers while reducing the impact of development on surrounding properties.

While requirements vary between municipalities throughout North and South Carolina, Raleigh’s regulations provide a useful example of why mature trees should be considered early in commercial landscape planning.

Preserving Existing Trees Can Support UDO Compliance

Raleigh’s UDO allows qualifying existing trees and shrubs to receive credit toward required landscaping. Existing vegetation that meets the applicable requirements can be preserved and credited on a tree-for-tree basis. However, unhealthy, dead, or hazardous trees do not qualify for this credit.

This makes existing mature trees an important consideration during site planning. Removing an established tree may mean replacing it with new plant material, while preserving a healthy tree can potentially satisfy part of the property’s landscaping requirements.

For developers, identifying valuable existing trees before construction begins can therefore influence both the landscape design and the overall development strategy. Article 9.1 of Raleigh’s UDO covers Tree Conservation.

Mature Trees Need Protection During Construction

Preserving a tree on a landscape plan is only useful if the tree survives construction.

Raleigh’s UDO requires the critical root zones of preserved trees to be protected, with no tree-disturbing activity within those areas. Tree protection fencing must also be used during construction.

This is particularly important on commercial construction sites, where grading, excavation, utility installation, paving, and heavy equipment can potentially damage tree roots even when construction does not directly affect the trunk.

Proper coordination between the landscape contractor, developer, site contractor, and other trades can help protect valuable trees throughout the construction process.

Heritage Trees Deserve Special Consideration

Some mature trees receive additional consideration under the Raleigh UDO. The ordinance defines a heritage tree as a healthy, non-hazardous single-trunk shade tree measuring at least 24 inches in diameter at breast height (DBH), or a single-trunk understory tree measuring at least 12 inches DBH.

Under certain conditions, a heritage tree and its critical root zone can be established as an optional tree conservation area, with the critical root zone potentially receiving double credit toward a development’s tree conservation requirement.

For commercial developers, identifying heritage trees early in the planning process can influence how a site is designed. Rather than treating a large existing tree as an obstacle, developers can potentially incorporate it into the landscape plan and preserve its established canopy, character, and visual impact. Raleigh’s heritage tree provisions have specific requirements for tree condition, root zone protection, arborist evaluation, and preservation planning.  Developers can also receive double credit toward tree conservation requirements if a heritage tree’s entire critical root zone is fully protected from disturbance.

Heritage tree requirements vary by municipality, so Raleigh’s regulations should not be assumed to apply throughout North Carolina, South Carolina, or any other state.

Mature Trees Can Improve Commercial Curb Appeal

Beyond regulatory considerations, mature trees and heritage trees can significantly improve the appearance of a commercial property.

Established trees can:

• Frame entrances and driveways
• Provide shade for pedestrians and gathering areas
• Screen parking lots and service areas
• Soften large buildings and paved areas
• Enhance streetscapes
• Create a more established appearance
• Provide visual continuity between natural and developed areas

For new commercial developments, preserving existing trees can help a property look established much sooner than relying exclusively on newly planted trees.

New Trees Still Have an Important Role

Preserving mature trees does not eliminate the need for new landscaping. Commercial properties often require additional trees and shrubs to satisfy landscape plans, fill gaps in existing vegetation, provide screening, or create a cohesive overall design.

Raleigh’s UDO establishes specific standards for trees planted to satisfy landscaping requirements. For example, required shade trees generally must be locally adapted species with an expected mature height of at least 35 feet and a mature crown spread of at least 30 feet. They must also meet minimum size requirements at planting.

The result should be a landscape that combines the immediate benefits of preserved mature trees with the long-term benefits of properly selected new plantings.

Designing Around Existing Trees

Preserving a heritage or mature tree can sometimes require adjusting other aspects of a commercial landscape. Walkways, parking areas, utilities, drainage infrastructure, lighting, and new plantings may all need to be coordinated around existing trees and their root zones.

This is where experience with commercial landscape installation becomes especially important. A landscape contractor needs to understand not only where plants go, but also how landscaping interacts with the rest of a construction project.

Raleigh’s UDO also requires landscaping to avoid obstructing motorists’ views and comply with applicable sight triangle requirements.

Mature Trees and Tree Conservation Areas

Mature trees can also be part of designated tree conservation areas. Article 9.1 of the Raleigh UDO establishes requirements for tree conservation and identifies preservation of existing trees and healthy tree stands as an important component of those areas.

In some circumstances, protective yards can also be replaced with qualifying tree conservation areas.

Because tree conservation, landscaping, grading, and site development can overlap, these considerations should be addressed well before landscape installation begins.

Work With Pipeline Landscape to Create Outstanding Commercial Landscapes

Pipeline Landscape works with developers, builders, municipalities, and commercial property owners throughout North and South Carolina. Our commercial landscaping experience includes tree installation, landscape buffers, streetscapes, entrance landscaping, hardscaping, drainage, irrigation, and ongoing landscape maintenance.

We understand that commercial landscaping is about more than installing plants. Successful projects require careful coordination with site plans, construction schedules, existing vegetation, drainage, utilities, and applicable requirements. We also appreciate the value of mature tree cover. Established vegetation creates shade, oxygen, character, and more. When we plant new trees, it is with the understanding that they are the mature and heritage trees of the future and should be placed with that understanding in mind.

For developers working on projects where mature trees and landscape requirements are important considerations, Pipeline can help every step of the way, from planning to finished landscape. Contact us to learn more.