We are stewards of a living plant collection that contains more than 10,000 taxa. Like museums who manage and acquire objects, we are continually seeking to strategically expand our collections, while caring for our plants and sharing plant materials with other horticultural institutions.
The origins of the collection date back to 1798, when the Peirce family began planting trees on the land—long before the establishment of Longwood Gardens. Many of these trees can still be found in Peirce’s Park, and represent the oldest cultivated section of the Gardens. Several are Pennsylvania state champion trees.
These trees provided the inspiration for Longwood Gardens founder and visionary, Pierre S. du Pont, who purchased the property to conserve the trees, while the surrounding land provided the template for Gardens expansion. After Longwood Gardens was established in 1906, Mr. du Pont rapidly built collections of his favorite plants from around the world. This original collection established by Mr. du Pont provided the template for our modern collections, which are defined and categorized by seven broad roles that serve the interests of the Gardens.
The Role of Living Collections at Longwood Gardens
The living collections at Longwood Gardens serve myriad purposes, and are curated with the following roles in mind:
Heritage
Essential for the preservation of Pierre S. du Pont’s and Longwood Gardens’ legacy and for the horticultural heritage of the region.
Display
These plants fuel the innovative, ever-changing displays throughout our Gardens.
Educational
These plants support the specific needs of instructors who teach a variety of courses and programs at Longwood throughout the year.
Research
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.
Environmental
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.
Core Collections
Within the broader roles outlined above, we have prioritized certain groups of plants because they are important to our overall collection and to the preservation of our horticultural heritage and legacy; because they serve specific horticultural themes and programs; and because they specifically serve the mission of Pierre S. du Pont. These represent some of our most prominent plant collections and most can be seen at Longwood Gardens throughout the year.
Boxwood (Buxus)
As the cornerstone of the French and Italian gardens Pierre S. du Pont strived to duplicate, boxwoods were among the most important and most frequently used plants from the beginning of Longwood Gardens. Some of Mr. du Pont’s original boxwood plantings are still found throughout the Gardens, and they are an integral part of the Main Fountain Garden. Over the last 15 years, we have also collected boxwoods from wild areas of the Mediterranean region, where they occur naturally. This work has resulted in one of the largest collections of wild-collected boxwoods in the nation. Given the recent concerns about boxwood blight in the US, the wild-collected plants are particularly important since there may be disease-resistant plants among the many accessions.
Camellia (Camellia)
Typical of gardens throughout the southern US, Mr. du Pont established large collections of camellias in the conservatories, where these winter-blooming flowers could be appreciated. Longwood Gardens lies at the northern edge of the area where camellias can be successfully cultivated outdoors, and we’ve been evaluating potentially hardy camellias since the late 1950s. This has resulted in three commercial introductions (C. × williamsii ‘Aida’, C. japonica ‘Longwood Centennial’, and C. japonica ‘Longwood Valentine’). The cold hardiness breeding program is still active and is the longest running breeding program at Longwood Gardens.
Chrysanthemum (Chrysanthemum)
Comprised primarily of hybrids and cultivars developed in Japan and China, these mums are used for the world-class Chrysanthemum Festival on display in the conservatory each autumn. The collection consists of several categories of cultivars that are used for specific purposes, including the well-known “Thousand-bloom chrysanthemum” that is the highlight of the display each year.
Deciduous Azalea (Rhododendron)
Most visitors to Longwood Gardens are familiar with the riotously colored deciduous azaleas—some of Pierre S. du Pont’s most beloved plants—that once grew between the lower reception suite and the Main Fountain Garden. Those particular plants were hybrids (Ghent and Rusticana) imported from Belgium, but this collection has been expanded to include US native deciduous azaleas that are featured in Peirce’s Woods.
Orchid (many genera)
With over 3,000 accessions, orchids comprise our largest single collection, part of which can be seen throughout the year in the Orchid House of the Main Conservatory. Some of the collection’s major components include the classic Cattleya hybrids that date from before 1950; Masdevallia; large-flowered terrestrial orchids in the genus Disa; and many others. The best times to view these collections are winter and spring, although many orchids in the collection flower throughout the year.
Peirce’s Trees (many genera)
This is the original collection that started the path to what we now know as Longwood Gardens. It is composed of trees planted by the Peirce Brothers from 1798 until the mid-1800s, and consists primarily of species native to the US.
Water-platter (Victoria)
Along with the waterlilies, these ‘Vegetable Wonders’ or water-platters are the most recognizable members of the waterlily pools during the summer months. This collection is of particular importance to Longwood Gardens because of the hybrid—Victoria ‘Longwood Hybrid’—created at Longwood Gardens by aquatic plants expert Patrick Nutt. Although Victoria are perennial plants native to South America, in our climate they are treated as annuals and will complete their entire life cycle in less one year. Each year our aquatic plant experts hand-pollinate the flowers to generate a new crop of seeds for next season’s display. These seeds are also distributed to horticultural institutions around the world.
Waterlily (Nymphaea)
Our waterlily collection is accredited as one of the best waterlily collections in the United States by the Plant Collections Network (PCN). This diverse collection, consisting of some of the finest tropical and hardy waterlily hybrids produced by the most noteworthy breeders, is a mainstay of the waterlily pools during the summer months at Longwood.
Other Core Collections
Bonsai
A legacy collection at Longwood, these will be on display in our new Bonsai Courtyard in 2024, as part of our Longwood Reimagined project.
Holly
This is primarily a legacy collection comprised of accessions made by Pierre S. du Pont. Two selections, Ilex × attenuata ‘Longwood Gold’ and Ilex opaca ‘Longwood’ have been released and can be found for sale in the nursery industry. Hollies are also important native plants that are widely used to rehabilitate and increase plantings.
Lilac
One of the du Ponts’ favorite groups of plants, this collection consists of old-fashioned lilac (Syringa vulgaris) cultivars. The bulk of this collection can be found north of the Topiary Garden.
Magnolia
This collection at Longwood is of historical importance and features many large, old specimens of several North American native magnolia species.
Oak
Stalwarts of gardens throughout the world, oaks feature prominently throughout our outdoor displays at Longwood, but are most easily seen on Oak Knoll.
Notable Plants in the Living Collection
There are many noteworthy plant specimens at Longwood Gardens, but some stand out from the pack because of their rarity, size and stature, remarkable beauty, or one-of-a-kind stories. Here is a sample worth seeing during your next visit.
Magnolia acuminata var. subcordata ‘Peirce’s Park’
This yellow-flowered cucumber magnolia was planted by the Peirce brothers and was one of the oldest specimens at Longwood Gardens until it fell on April 30, 2021. Thought to have arisen from the original collection of early US plant explorer André Michaux, this historic specimen was one of the largest of its kind in the world. Propagules of this historic tree have been planted in other areas of Peirce’s Park. Learn more.
Encephalartos woodii
One of the rarest plants in the world, this South African cycad has been a sentinel of the East Conservatory since 1969. Originally acquired from a wild collected plant in South Africa, this species is now extinct in the wild and only male plants still exist.
Victoria ‘Longwood Hybrid’
This is one of Longwood’s signature plants and one of the mainstays of the waterlily pools in summer. This remarkable hybrid bears the Longwood name because it was created—and is renewed each year—at Longwood Gardens. Despite their size, Victoria water-platters are annuals, meaning that they grow from seed, flower, set seed, and die within a year and must be restarted from seed each year.
The Plant Collections Policy
In 2011, a formal plant collections policy was developed to add a framework to the scope and roles of our collection. This collections policy was revised in 2017 to suit the ever-evolving living collection, and will be updated again by the end of 2022.