Author: Stephanie Krull, Landscape Architect, Southwestern University
Bee Campus Affiliate: Southwestern University, Georgetown, TX
USDA Plant Zone: 8b
Cullen Administration Building Pollinator Garden
Less than one year ago, the Cullen Administration Building was surrounded by a rock garden that had good intentions, but some felt it gave a chaotic first impression of Southwestern as people drove down University Avenue and encountered their initial view of campus. The most dramatic element in this garden was the grove of Live Oaks dominating the corner of University Avenue and Maple Street. The largest has a trunk that is 56 inches in diameter. As magnificent as they are, these 11 trees create a significant amount of shade, and planting under them presented numerous challenges.
The south side of the Cullen Building, however, was bathed in sunlight for a good portion of the day. This inspired a plan to simplify the understory below the Live Oak trees, and create a pollinator garden adjacent to the building. This garden would be filled with native drought tolerant plants. The colorful blooms would attract and host pollinators in a space with minimal traffic. Visitors to this garden come by choice, and could enjoy the activity and beauty they discovered here. Passersby on the street would see a bright spot of color, visible just beyond the cool shade of the Live Oak trees.
Central Texas is known for its affection for native landscaping, and the resources to select and purchase native plants are plentiful. Most of the existing plants planted around the Live Oaks were not native. We decided to remove all the plants except the Texas Mountain Laurel, replanting them elsewhere when possible. Most of the stone was removed, including 31 large boulders and many bucketloads of river stone, which was stockpiled for use elsewhere. A two-foot-wide border of river stone was retained to provide a space for golf cart traffic to leave the sidewalk without creating ruts or doing damage to the adjacent plant material. This boundary also allows the perennials, heavy with bloom, to lay over without blocking the sidewalk. This rock border did not have landscape fabric underneath it, since it is in the shade with minimal weed pressure. All the small boulders were retained in a pile to provide edging between the flower beds and turf.
The project was organized into three phases; demolition, pavement construction and tree/shrub/sod planting, and perennial planting. The first two phases were completed by a contractor. The demolition was slow and careful to prevent damage to the trees. Palisades Zoysia lawn was installed, due to its tolerance of shade and drought. Most areas of deep shade were covered with local hardwood mulch. The Texas Mountain Laurels were all pruned to a similar height, and new native small trees and shrubs were planted all around the building.
The third phase, the perennial planting, was completed as a volunteer project on SUnity Day 2022. This event occurred on September 13th, and fourteen volunteers worked hard to plant nearly 400 perennials. Once the planting was completed, recycled plastic furniture was added to the patio. Two self-watering hanging baskets were added to the light pole on the patio to add even more color and pollinator opportunities. The final touch was an umbrella so guests could relax in the shade and enjoy the view of the flowers and butterflies soon to come.
The above bed is the hottest, driest bed by far, and contains two large masses of Senna lindheimeriana, a West Texas native. It also has three types of Salvia (S. occinea, S. leucantha, S. greggii), as well as Bulbine and Lantana, two adapted perennials that are non-invasive and well suited to the climate and soils of central Texas. Three different Agave plants, Acanthus and some native Blue Grama grass round out the collection for this bed. The shadier beds contain large masses of Smooth Aster, Turk’s Cap, Artemisia, Society Garlic, Ageratum, Rock Rose and Texas Star Hibiscus. We plan to fill in between the perennials with more self-seeding annuals and biennials. Many of the shrubs, such as American Beautyberry, provide heavy bloom opportunities as well.
This area was previously irrigated so it was modified to provide water during establishment. This was necessitated by the need to install in the hot summer month. In the future, the irrigation will only be used during extremely water-scarce times. We plan to label plants and provide pollinator signage designed by students.
This garden provides a high-profile, beautiful, and educational feature that we hope will become an asset to the university and local ecology over time, and offer a blueprint for future plantings on campus.