• Start-up
  • Planning
  • Action
  • Evaluation

Longwood Gardens is in the beginning phases of planning for climate change.  We are assessing the species on the property and will propose which species should be phased out and which should be introduced.

Longwood Gardens is analyzing the species to be planted in the gardens for cold hardiness, heat tolerance and longevity. Located in the mid-Atlantic, the seasonal temperatures and rainfall are more apt to change quickly. Many species are at the limit of their range in this area. Selecting wisely will provide less unwanted, unexpected changes in the future.

Project Area

View of diverse vegetation at Longwood Gardens
Longwood Gardens is a 1,077 acre parcel situated in southern Chester County, Pennsylvania. The property is mixed use. The gardens proper encompass 400 acres. There are more than 9,000 identified and tagged trees. These trees represent many taxa from around the world. There are several successional forest plots of different ages on the property as well.

Management Goals

the garden features ever-changing displays
The living collections at Longwood Gardens are curated with the following roles in mind:


Essential for the preservation of Pierre S. du Pont’s and Longwood Gardens’ legacy and for the horticultural heritage of the region.


These plants fuel the innovative, ever-changing displays throughout our Gardens, but are most apparent in the Main Conservatory, Peirce-du Pont House, Flower Garden Walk, Idea Garden, and Student Exhibition Garden.


These plants support the specific needs of instructors who teach a variety of courses and programs at Longwood throughout the year.


Used to support research projects involved in the development of innovative horticultural techniques, plant breeding, or evaluation of plants new to the horticulture market for Longwood specific purposes.


These plants play a critical role in the health, quality, and conservation of our local ecosystem and natural lands.

Germplasm Preservation

Essential to the preservation of popular horticultural programs, for breeding purposes, and to manage and conserve the health of our collection.

Plant Conservation

Many Pennsylvania native plants have become rare, and several of these are found and stewarded on Longwood Gardens property. We have specifically sought out others to help build a Plant Conservation Program.

Climate Change Impacts

For this project, the most important anticipated climate change impacts include:
Susceptibility to pests and disease
Changes in precipitation patterns
Changes to hardiness zones

Challenges and Opportunities

Climate change will present challenges and opportunities for accomplishing the management objectives of this project, including:


Past management history makes some trees more vulnerable to current and future stressors
The species composition was selected for past, not future climate conditions
There may be a reduction in the number of species that could be used for planting
More extreme weather events could lead to damage to large trees
More invasive species to manage, including plants, insects, and pathogens


Ability to use more southern species
Can use climate change as an opportunity to redesign the garden for future needs
Could increase diversity by planting species that are able to survive in a warming climate

Adaptation Actions

Project participants used the Adaptation Workbook to develop several adaptation actions for this project, including:

Assess irrigation systems, assess drainage capabilities, and ensure new plantings are suitable for the location
Continually research possible new threats and create a plan, monitor, increase reaction times. Remain in contact with Universities for current information and processes.
Create a replacement plan for when vulnerable species in the collection are lost.


Project participants identified several monitoring items that could help inform future management, including:
Maintain accurate records regarding plant health, selection and reasons why actions were taken.
Review trees in decline and determine if climate change was a stressor, document all actions.

Learn More

To learn more about this project, contact
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Insect pests
Invasive species

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