ORNL Arboretum

The Oak Ridge National Laboratory Arboretum (ORNL Arboretum) is situated on the western portion of the Oak Ridge National Laboratory in Oak Ridge, Tennessee. All of the li sted trees in this certified arboretum are native species found in Tennessee, complete with walkways leading throughout. Additionally, the trees are managed by ORNL’s own Landscaping Committee, who decide on what species should be planted and the means to do so. The ORNL Arboretum is but one of the few projects that showcase the Department of Energy’s efforts in encouraging pollinator habitat and promoting native tree species.


DOE recognizes ORNL Arboretum with Sustainability Award
Strategic Partnerships for Sustainability Category
ORNL Arboretum Accreditation: Wisdom is Stored in Trees
Highlights the Sustainable Landscaping and Land Use Roadmap and how the new ORNL Arboretum contributes to sustainable landscaping & operations and is directly applicable to the DOE Goal category covering federal High-performance Sustainable Buildings. (Jamie Herold, project lead)

ORNL now has an arboretum
by Abby Bower, ORNL Today
The new certification will showcase DOE’s efforts to preserve native trees
In May 2020, a nearly 26-acre area in ORNL’s west campus was certified by ArbNet, an internationally recognized arboretum. The new ORNL Arboretum, which is accessible to all badged employees and visitors, contains 52 different species of trees native to East Tennessee – from the Tennessee state tree, the tulip poplar, to the common hackberry.




Tree Species

Find out more about each tree species by clicking the botanical name below. The Lady Bird Johnson Wildflower Center Plant Database offers information on tree characteristics, bloom time, natural habitat, and growing conditions. It also provides landscaping benefits (florific, fall color, winter interest, fragrant) and wildlife benefits (birds, pollinators, larval host plant, etc.)

Tree Species (Alphabetical)
# Botanical Name Common Name
1 Acer x freemanii Freeman Maple
2 Acer negundo Boxelder
3 Acer rubrum Red Maple
4 Acer saccharum Sugar Maple
5 Aesculus flava Yellow Buckeye
6 Betula nigra River Birch
7 Carpinus caroliniana American Hornbeam
8 Celtis laevigata Sugarberry
9 Celtis occidentalis Common Hackberry
10 Cercis canadensis Eastern Redbud
11 Cornus florida Flowering Dogwood
12 Cornus racemosa Gray Dogwood
13 Diospyros virginiana Common Persimmon
14 Fagus grandifolia American Beech
15 Fraxinus pennsylvanica Green Ash
16 Gleditsia triacanthos f. inermis Thornless Honeylocust
17 Ilex opaca American Holly
18 Juglans nigra Black Walnut
19 Juniperus virginiana Eastern Redcedar
20 Liquidambar styraciflua American Sweetgum
21 Liquidambar styraciflua ‘Rotundiloba’ American Sweetgum
22 Liriodendron tulipifera Yellow Poplar
23 Magnolia grandiflora Southern Magnolia
24 Magnolia virginiana Sweetbay Magnolia
25 Nyssa sylvatica Black Gum
26 Pinus echinata Shortleaf Pine
27 Pinus strobus Eastern White Pine
28 Pinus taeda Loblolly Pine
29 Platanus occidentalis Sycamore
30 Populus tremuloides Quaking Aspen
31 Prunus serotina Black Cherry
32 Quercus alba White Oak
33 Quercus bicolor Swamp White Oak
34 Quercus falcata Southern Red Oak
35 Quercus muehlenbergii Chinkapin Oak
36 Quercus nigra Water Oak
37 Quercus palustris Pin Oak
38 Quercus phellos Willow Oak
39 Quercus prinus Chestnut Oak
40 Quercus rubra Northern Red Oak
41 Quercus shumardii Shumard Oak
42 Quercus stellata Post Oak
43 Rhus copallinum Winged Sumac
44 Salix nigra Black Willow
45 Sassafras albidum Common Sassafras
46 Taxodium distichum Common Baldcypress
47 Tilia americana American Basswood
48 Tsuga canadensis Eastern Hemlock
49 Ulmus alata Winged Elm
50 Ulmus americana American Elm
51 Ulmus rubra Slippery Elm
52 Viburnum rufidulum Rusty Blackhaw



In 2019, the ORNL Arboretum was certified through the ArbNet Arboretum Accreditation Program, an internationally recognized arboretum accreditation program, as a level one arboretum. Visit the ORNL Arboretum ArbNet page to learn more about the certification and the ArbNet Program.

  • “The Morton Arboretum has compiled a database of global tree-focused public gardens that is the basis for the ArbNet collaborative network. The Morton Register is a constantly growing list, identifying organizations that collect and display trees, shrubs, and other woody plants for the benefit of the public, science, and conservation.” Quote from arbnet.org



Native plants and sustainable landscaping

Numerous objectives for the ORNL Arboretum include highlighting the native beauty of deciduous forests within the DOE Complex and to provide research opportunities for students and scientists. To showcase sustainable landscaping practices, typical ornamental flora is replaced by local plant species in an appropriate community design.

Written in 2011 “The goal of the Oak Ridge National Laboratory (ORNL) Sustainable Landscapes Initiative 2020 is to provide a framework that guides future environmental resources and sustainable landscape practices on the ORNL campus.”

An invasive insect pest leads ORNL to a campus tree inventory

In 2014, an urban forester with the Tennessee Division of Forestry evaluated trees on the ORNL campus that had been impacted by the Emerald Ash Borer (a non-native invasive insect species that kills ash trees). This inspired the need for an urban (campus) tree inventory to monitor species, size, location, and health of campus trees. As a result, students from multiple universities have participated in ORNL internships conducting tree inventories, insect surveys, arboretum design, and sustainable landscaping. This inventory eventually became the inspiration for a Master’s research project at the University of Tennessee.

Designating a space

The ORNL Arboretum has one of the most diverse selection of trees on campus (52 of the 62 native tree species found on campus). The inspiration and design is described in the ORNL Today article that shared the Arboretum designation with ORNL staff.

This American basswood is just one of 52 native tree species found in the ORNL Arboretum.

What do an eastern hemlock, a common sassafras and a chinquapin oak have in common?


Got you stumped? It’s not a dendrology question. These are all tree species found in Oak Ridge National Laboratory’s newly designated arboretum.

In May, a nearly 26-acre area in ORNL’s west campus was certified by ArbNet, an internationally recognized arboretum accreditation program, as a level one arboretum. The new ORNL Arboretum, which is accessible to all badged employees and visitors, contains 52 different species of trees native to East Tennessee—from the Tennessee state tree, the tulip poplar, to the common hackberry.

An arboretum, as defined by the American Public Garden Association, is a place where trees or woody plants are grown to be studied by the public. Only areas that contain at least 25 kinds of trees that have been properly labeled, are accessible to the public in some way and are maintained by a governing body with a strategic plan to care for the trees can receive the ArbNet title of level one arboretum.

The purpose of seeking that designation at ORNL, says natural resources intern Nicholas Oldham, was to showcase the Department of Energy’s efforts to preserve native tree species and improve pollinator habitats. Oldham worked under the mentorship of ORNL plant ecologist Jamie Herold for a year planning, identifying trees, researching accreditation requirements and creating maps in order to make the arboretum—which contains exclusively native trees—a reality.

“This is a great way to do it, starting with an arboretum, because it concretes a plan,” Oldham said. “Now it’s certified; now these trees are here to stay.”

With 52 of the 62 tree species on ORNL’s campus featured in the arboretum, it’s a diverse example of native trees found at the lab, Herold says. This allows ORNL’s Landscaping Review Committee to promote sustainable landscaping practices by showing visitors the wide range of native tree species they might try planting in their own yards.

According to Herold, while urban trees in general provide environmental services like reducing air pollution, preventing runoff and sequestering carbon, native trees have added benefits. In addition to their natural beauty, native trees help provide food and suitable habitats for other native species including important pollinators like birds and insects.

For example, the native eastern redbuds found in the arboretum flower in early spring and produce a vital food source for pollinating insects in the dormant period before other species bloom in early summer, Oldham says.

It was his love for these insects, not necessarily trees, that spurred Oldham’s commitment to the project. Known to his friends as “the bug guy,” he is planning an experiment in the arboretum to determine exactly which of these pollinators are present at ORNL.

Other next steps include pursuing additional certifications and potentially expanding the arboretum. Oldham is applying for another arboretum accreditation through the Tennessee Urban Forestry Council and says he believes that with enough work, the space could grow to include more of ORNL’s campus.

For now, it’s just awaiting visitors.

“The arboretum was [established as] a way to provide education and also get people walking around outside and enjoying nature,” Herold said.

The ORNL Arboretum includes most of the area west of First Street, wrapping all the way around Building 1504 in the south, Building 1060 in the west, and around the parking lot adjacent to Building 1005 at its northernmost point.

While most of the trees are not physically labeled yet, signs describing individual trees are soon to come. A larger sign will mark the arboretum’s location.

More information about the ORNL Arboretum, including maps and information on tree species will soon be added to the ORNL Landscape Management webpage.


The Arboretum is uniquely positioned to benefit the ORR National Environmental Research Park, one of seven DOE outdoor laboratories in support of investigating effects of various energy technologies on environmental processes.  Within the heart of the eastern deciduous forest ecoregion, the park contains wetlands, prairies, streams, reservoirs, and other uncommon habitats in addition to upland mixed forests. Scientists and educators enjoy its many unique advantages, including a large information base, access to onsite experts, and proximity to educational institutions.

Urban Forestry, Ecosystem Services, and Soil Properties: In 2018, an inventory of tree species on the ORNL campus was conducted to provide data for use in studies of the economic and environmental benefits of urban trees. The research focused on over 1100 landscape trees across the ORNL campus, including those in the ORNL Arboretum. The thesis titled Revitalizing Brownfields and Greyfields at Oak Ridge National Laboratory to Promote Urban Forestry Management was completed in 2019. A manuscript titled “i-Tree Eco Analysis of Landscape Vegetation on Remediated Areas of Oak Ridge National Laboratory” has been accepted to the Open Journal of Forestry and is pending publication. A second publication is in the works. This research included urban trees throughout the ORNL campus, however, the campus was divided into zones for data analysis and Zone 1 was the ORNL Arboretum

Insect Herbivory: A summer intern  collected data on insect populations in the grassland portions of the ORNL Arboretum. He continued analyzing this data for his senior thesis at UTK (Dept. Ecology & Evolutionary Biology), and recently presented a research poster at EURēCA 2020 (Exhibition of Undergraduate Research and Creative Achievement). . His poster,  Insect herbivore community diversity differs among wildflower species and changes over time, received top honors at the University of Tennessee EURēCA 2020 (Exhibition of Undergraduate Research and Creative Achievement) including the Award of Excellence and Gold Award. 

Ecological and Economical Benefits of Reduced Mowing: A Six Sigma collaborative project between the Natural Resource Management Program and Roads & Grounds was designed to study the benefits of converting mowed turf grass into native plant landscaping. Based on the relative success of these two plots, plans are to expand such treatments into other areas on and around the campus toward the goal of reducing mowing and maintenance costs, reducing emissions from mowing and establishing pollinator habitat in support of the DOE pollinator health initiative.

Monarch Watch participation: ORNL participates in the Monarch Watch Program, a program where citizen scientists and organizations catch, tag, and document monarchs in order to track the annual North American migration of the Monarch butterfly. Each monarch is  tagged with an small sticker that has an individual identification number, and then released. The Arboretum contain multiple sources of milkweed (the host plant for monarch caterpillars) in the grasslands and landscaping. The numerous species of wildflowers, shrubs and trees provide ample nectar sources and habitat. Multiple monarch butterflies have been caught and tagged within the ORNL Arboretum, adding data to an international study on monarch migration, and is included as part of ORNL’s pollinator habitat supporting the Presidential Memorandum on Pollinator Health.

Forest Health: Although a small percent of the overall reservation acreage, the ORNL Arboretum plays an important role integrating the Oak Ridge National Laboratory with the adjacent forested area.


Benefits of obtaining Arboretum certification include membership in an international network of global tree-focused collaborative organizations. The register constantly growing; identifying organizations that collect and display trees, shrubs, and other woody plants for the benefit of the public, science, and conservation. The network highlights the economic and environmental benefits of urban trees, while also providing early detection of hazards/risks to urban forests.

Multiple strategic partnerships between ORNL Divisions, state and federal programs, and non-government organizations will benefit from the Arboretum. Recipients include ORNL F&O, Environmental Sciences Research Divisions, and Environmental Protection Services. Other partners include the Tennessee Department of Forestry, Tennessee Wildlife Resources Agency, and independent specialists.

ORNL’s commitment to urban forestry and certification of the Arboretum brings us closer to community partners such as the City of Oak Ridge, the University of Tennessee, Tennessee Department of Agriculture, and the Tennessee Urban Forestry Council.


Urban Forests offer an abundance of ecosystem services.

The Master’s Research Project found that:

  • “The estimated gross sequestration of all trees in this assessment was estimated to be 9.5 tons of carbon per year with an associated value of $1,360. In addition, they are estimated to store 320.6 tons of carbon amounting to $45,800 in annual benefits.”
  • “Trees recorded in this inventory were estimated to intercept 4,711 m3 (1,244,620 gallons) and helped to mitigate runoff by an estimated 1,035m3 (273,418 gallons) per year with an associated value of $2,440.”