Our Gardens

History

Mrs. Emily C. Diffenback of Wilmington, Delaware, was an alumna and former president of the Delaware Federation of Garden Club. Emily donated funds to establish and maintain gardens around the University of Delaware’s campus in 1966.

Professors of plant science Dr. Charles W. Dunham and Dr. Richard W. Lighty designed this namesake garden as a place of beauty, respite, and education for students at the college as well as graduate students in the Longwood Program in Ornamental Horticulture. Recycled soil from the Wolf Hall excavation site (referred to as “the knoll”) was used to form one large mound and several smaller ones, along with a low stone retaining wall running through the garden’s length.

The Emily B. Clark Garden was formally dedicated in May 1973. Featuring ornamental plants and notable donations like a Paperbark Maple (Acer griseum) from Millcreek Nursery (the former nursery of Mr. and Mrs. William H. Frederick, Jr.), it laid the foundation for a vast woody plant collection and an official Holly Arboretum designation.

Plant list for 2025 Planters

History

The Dunham Garden was named in honor of Dr. Charles W. Dunham, who taught at the University from 1954 to 1984 and co-founded UDBG with Dr. Richard W. Lighty.

Designed by students from several Landscape Architecture classes and former UD Professor Gary Smith, the plantings include hollies and magnolias, two of Dr. Dunham’s favorite plants. The donations from various nurseries for this garden honor Dr. Dunham’s 30-year involvement in plant societies, collaboration with the nursery industry, and his role as an educator.

Dr. Dunham passed away peacefully on July 1, 2021, in Bethesda, Maryland. He was 99.

History

In the 1960s, the Fischer Greenhouse garden was the site of a one-acre rose garden maintained by undergraduates in the horticulture program—a precursor to the current internship program.

History

The Herbaceous Garden was created in 1986 as an outdoor laboratory for students enrolled in the Herbaceous Plant Materials class. At its conception, plants were laid out in rows within rectangular beds maintained by an enthusiastic group of volunteers who later founded the membership group, UDBG Friends. In 1989, this group redesigned the garden into a series of curvilinear beds with mulch paths.

In the early 1990s, an undergraduate student studying landscape design redesigned the beds and paths with grass paths. In 2009, with a donation to create Crossan Circle, the paths were updated to brick pavers, making the garden accessible to all.

In 2013, three professional designers participated in a design charrette to create a more enticing entrance that would facilitate movement between the Landscape Color Trials, All-America Selections Display Garden, and the Lepidoptera Trail. The winning design created by 1980 Plant and Soil Science alumnus Shipley Allinson featured a wooden pavilion, swale, new borders, and a stone path leading to the Lepidoptera Trail.

The role of the Herbaceous Garden has evolved since its creation. In 2005, a change in the instructors of the herbaceous plant course ushered in a new wave of opportunities. With the garden no longer being the primary resource for students to study plant material, greater diversity and flexibility were introduced.

The Landscape Color Trials and All-American Selections Display Garden feature bold sweeps of colorful annuals, tropical plants, and tender perennials. Inspiration abounds with award-winning plants, just-released annuals, and creative trellising using repurposed furniture, fences, and other recycled props.

Many of the Trial Garden’s displays have won the prestigious All-American Selections award, an honor given to plants consistently ranked the best performing in trial gardens throughout the U.S. Every two weeks between summer and fall, a UDBG staff member ranks each trialed plant’s foliage and flowers.

Searching for low-maintenance plants? Explore these beautiful, adaptable and low-maintenance options. All plants grown in the Trial Garden are watered and fertilized for only a week or two after planting, then must subsist on only rainwater for the rest of the growing season.

Ideal for observing birds, butterflies, and moths, this garden displays many trees, shrubs and perennials indigenous to the Eastern United States. The plantings border a grassy lawn (formerly the site of the turf research area and a small golf course), and those along the road’s edge act as an important corridor to UD’s research area, Ecology Woods.

Notable areas of the garden include the Boreal Forest, which contains mostly coniferous and some deciduous trees such as Sugar Maple (Acer saccharum), Paper Birch (Betula papyrifera), and White Spruce (Picea glauca). Visitors will enjoy walking beneath the canopy of trees in the hot summer months or eating ice cream on one of the benches or observation areas meant to simulate a backyard environment.

The adjacent interpretive trail provides food for butterflies, moths and skippers (collectively known as the Order Lepidoptera) during both the caterpillar and adult stages of their life cycle.

Butterflies and Moths of Delaware List

History

This plant collection was established in 1992 partially through a grant from the Delaware “America the Beautiful” project.

The South Greenhouse Garden is full of ideas for homeowners who want to create a low-maintenance garden. The garden, sized like a small residential property, is surrounded by a low brick wall, deciduous hollies, and Oakleaf hydrangeas that create the illusion of a secluded courtyard.

A stunning display of flowers, berries, fragrances, and foliage underscore the four seasons of interest throughout the year. A proliferation of bulbs, daffodils, grape hyacinths, and spring snowflakes announce spring’s colorful arrival. Pineapple Lilies and resurrection lilies continue the bulb display into the summer when the array of true lilies explode into color. During the fall and winter, stately hollies catch visitors’ interest, and flowering sweet olive or false hollies fill the garden with their sweet, orange-blossom scent.

In addition to its multi-seasonal appeal, the South Greenhouse Garden is sustainable in design and maintenance. Designed by students and led by former Plant and Soil Science Professor Chad Nelson and Professor and Director of Landscape Architecture Program Dr. Jules Bruck, it comprises tough, low-maintenance plants that require minimal water and no fertilizers or pesticides to keep them healthy.

As you walk through the garden, you will notice that garden beds have replaced traditional turf lawns, making the garden more colorful, diverse, and wildlife and human-friendly.

The Townsend Hall courtyards feature unique plants that ordinarily cannot grow in northern Delaware. The microclimate created by the warmth and shelter of the building keeps the two courtyards at the back of the building warmer in winter. These conditions allow USDA Zone 8 and some Zone 9 plants to thrive in this protected spot. 

A wide range of broadleaf evergreens, including Daphniphyllum macropodum, Camellias, Southern oaks, Evergreen viburnums, Sweetspires (Itea sp.), and Mahonias, provide a year-round display. Plants such as False holly or Sweet olive (Osmanthus americanus), Magnolias, and Paperbush (Edgeworthia papyrifera) fill these courtyards with their fragrance during the spring and fall semesters. 

With its diversity of marginal evergreen trees, shrubs, the Townsend Hall Collection is a fabulous garden for viewing plants rarely seen in Delaware.

History

As visitors stroll through the Wetlands, they may be surprised to learn that this beautiful area used to be a dairy cow pasture at the UD Farm. The cows compacted the soil over time, creating a hardpan (impenetrable layer of soil) that prevented water from draining properly.

In the fall of 2008, the site was transformed into a thriving ecosystem that reduces runoff, improves water quality, increases plant diversity, and supports wildlife. It also serves an important function as an immersive environment where visitors can fully experience wetland wildlife.

The garden was designed with the Delaware Department of Natural Resources and Environmental Control. It features two bays, a low berm to capture water, and scattered stumps for structure and habitat. Students studying landscape design at UD developed the planting plan for trees, shrubs, grasses, and native wildflowers, with Professors Chad Nelson and Doug Tallamy supervising the planting efforts.

The Worrilow Hall Garden displays an extensive collection of viburnums, witch hazels, winter hazels, hornbeams, and oaks. Visitors will find a number of rare shrubs and trees, such as Parrotiopsis (Parrotiopsis jacquemontiana), and Chinese zelkova (Zelkova sinica), seldom seen in most gardens and landscapes.

History

In 1999, Dr. John Frett, professor of landscape horticulture and UDBG’s first director, started a project to establish plantings around Worrilow Hall. The goal was to extend plant collections for teaching purposes.

Kirk Himelick, a former professor of landscape architecture, designed a series of curvilinear mounds and beds that would serve as the project’s backbone. He also created a large central lawn that would later be used for events such as Ag Day and children’s summer camps. A fortuitous municipal construction project provided the soil fill needed to shape the garden, and a donation of plants from Princeton Nursery kicked off the collection.