Search our Collection Connection to learn more about plants and garden features of interest to you and where you can find them at the Arboretum. You can also view a map to help identify what is nearby.
More than 11,000 accessioned plants of over 2,500 taxa are growing in the Arboretum’s living collection. These include representatives of the temperate floras of North America, Asia, and Europe. This historic collection traces its foundation to John Morris’s interest in plants from around the world and includes plants collected in China by E.H. Wilson at the turn of the century. Many of the Delaware Valley’s "trees-of-record" (the largest of their kind) are found in the Arboretum. Most notable are the katsura and the trident maple.
Staff members have regularly engaged in plant collecting expeditions in Asia and the United States, increasing the diversity of plants available for today’s urban and community landscapes. Currently, plants from 30 countries are represented in the collection with a primary focus on Asian temperate species. Significant plant groups in the Arboretum’s collection include maples, magnolia species, native azaleas, members of the witchhazel family, roses, hollies, and conifers.
Help Protect Our Trees
Please note, visitors are not allowed to climb or sit on the limbs of trees. The Arboretum is home to a number of champion trees, some of which are very old. With 150,000 visitors annually, climbing becomes a safety issue for both children and the trees. We don’t want any visitors or trees to break a limb. Thank you!
With the diversity of our collections, there is seasonal interest throughout the year, for all levels of gardeners. Look for the following plants throughout the year:
December through February
Paperbark maple, stewartia, kousa dogwoods, hollies, and rare and unusual conifers of all shapes, sizes and colors.
March through June
Witchhazels, winterhazels, magnolias, cherries, maples, dogwoods, rhododendrons, azaleas, crabapples, roses, and stewartia.
July through September
Hydrangeas, summersweet, butterfly bush, chaste tree, sourwood, golden-rain tree, and annual and perennial displays.
September through November
Maples, black gum, sweet gum, dogwoods, oaks, and other colorful trees.
The Rose Garden will be closed for renovations until Spring 2023.
The Catalogue of Plants in the Living Collection
A catalogue of plants in the living collection is available at the front desk of the Widener Visitor Center. Most of the plants in the Arboretum are labeled and mapped, and this catalogue can lead you to plants in which you have an interest.