Scientific Research at Holden

The Holden Arboretum has been conducting original scientific research for more than 20 years and has a strong tradition of breeding superior, woody ornamental plants for the landscape; a tradition that continues.


The Holden property encompasses extensive high quality natural forest ecosystems (~3,000 acres) and conserving native forests is one of the institution’s primary missions. Thus, improving our fundamental understanding of the function and dynamics of native forests and how they respond to environmental change is another focus of the the Arboretum's Research program.


Our scientists, post-doctoral scholars and graduate students conduct basic and applied research in the following areas.


Plant Breeding

Using traditional plant breeding methods, researchers at the Arboretum are transferring disease resistance from wild rhododendron species to hybrid varieties that are grown as ornamental plants in gardens. The increased root rot resistance has also enabled these plants to be grown in much warmer climates (e.g. the Gulf South) where the root disease pressure is greater.


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A root rot resistant hybrid rhododendron growing in southern Louisiana USDA hardiness zone 9.


Plant Physiology

The 900+ species of Rhododendrons in the world originate from habitats ranging from sub-tropical to sub-arctic. Rhododendrons also have a broad diversity of leaf types.


Research in Rhododendron physiology at the Arboretum focuses on how leaf diversity relates to the evolution of habitat diversity.


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Forest Ecology

Our ecological research mission is focused on contributing to a better understanding and conservation of the diversity, health and function of natural forest ecosystems in Northeast Ohio.

Forest ecology research at Holden examines the mechanisms by which organisms tolerate environmental change and the importance of biological diversity to the function of forests.


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Forests like this one in Stebbins Gulch are the subject of study by the Arboretum's Research Department. Stebbins Gulch is one of 600 sites in the United States designated as National Natural Landmarks.
Soil fungi in the genus Inocybe colonizing the roots of a hardwood tree. These fungi form beneficial relationships with forest trees.

Soil Ecology

Researchers and students at the Arboretum are discovering what environmental factors affect soil fungi and bacteria and how these soil organisms affect plant growth. Research studies examine how human activities like climate change and air pollution can harm these beneficial soil organisms. Healthy soil and healthy soil food webs are important to conserve our natural areas and agricultural systems for future generations.


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Urban Ecology


Based at Cleveland Botanical Garden, the goal of the urban ecology research program is to develop reuse strategies for vacant urban land and understand the social and environmental impacts of such strategies. The program studies low-cost, low-maintenance methods of stormwater management and neighborhood stabilization.


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