George Washington University
OP-T2-47: Xeriscaping

As part of GW's Ecosystems Enhancement Strategy, the university will promote non-invasive/drought-resistant/adaptive/native plants on university grounds, using the following criteria for plantings-- appearance, adaptability, security, and survivability. The seven principles of Xeriscaping are a central part of the landscape planning at GWU. Proper water usage, plant selection, and cultural practices are essential for the success of any urban landscape. Large scale irrigation systems and areas requiring frequent watering are not efficient on a campus with large amounts of foot traffic, so proper planning and appropriate plant selection is essential. Example: Outside of the entrance of Lisner Hall, there is a very shallow, dry planting bed. The building eaves, large existing trees, depth of the planting bed, and ambient heat radiating from the concrete vault surrounding the bed were all taken in consideration when planning this planting. Previously, plantings required consistent irrigation to thrive, requiring the use of additional water and employee time. The solution was to fill the shallow, well drained beds with Prickly Pear Cactus (Optunia ssp), an incredibly tough Southwest US native cactus. The cactus thrive in the dry heat, require little care, flower prolifically, and have since been used to acquire cuttings to establish cactus beds in similar dry, hot areas, especially on the south side of buildings with large overhangs that block all precipitation.. This is an example of using a species best adapted to the area being planted to reduce water and labor input.