Location: Public Horticulture and Engagement Unit
2022 Annual Report
Objectives
Objective 1: Collect, propagate, preserve, evaluate, document, display, distribute, and introduce woody and herbaceous landscape ornamentals with enhanced aesthetic appeal, resistance to extreme weather, resistance to pests and diseases, and enhanced ecosystem benefits. Collection activities will focus on native plants due to difficulties with collecting plants in most other countries. [NP301, C1, PS1A]
Objective 2: Disseminate scientific and practical information to floral and nursery crop industries, to public gardens, to the increasing number of visitors to the U.S. National Arboretum and its Website, and to the general public interested in gardening. [NP301, C2, PS2B]
Sub-objective 2.a. Develop exhibits and interpretive signage that reflect current relevant ARS horticultural research programs, including the scientific mission of the U.S. National Arboretum.
Sub-objective 2.b. Develop educational programming to increase awareness of ARS research and germplasm preservation taking place at the U.S. National Arboretum.
Approach
The U.S. National Arboretum will continue to serve the public need for scientific research, education, and gardens that conserve and showcase plants to enhance the environment. This will be accomplished by maintaining outstanding gardens, plant collections, and public displays in an environmentally responsible and aesthetically pleasing manner. New ornamental cultivars and germplasm will be acquired using the Collections Policy and the newly developed Strategic Plan as a guide, and in support of the National Plant Germplasm System. Plants will come from nursery sources, wild-collected, or the USNA research program. Plants with superior landscape attributes will be propagated for distribution and evaluation. Staff will continue to utilize integrated pest management (IPM) in management of their collections and will explore the use or demonstration of other technologies such as solar power, green roofs, rain gardens, and water wise gardens as funds allow.
Plant records will be updated and coordinated with GRIN-global, and information will be uploaded to the publicly accessible Arboretum Botanical Explorer database. A new exhibit and educational program, GrassRoots, will be put in place. Educational opportunities will be optimized and implemented to provide formal and informal educational programming through exhibits, signs, publications, web pages, lectures, workshops, and tours. Volunteer and internship programs will continue to be supported.
Progress Report
Progress was made on all Objectives, which fall under National Program 301. Under Objective 1, The Gardens Unit enriches the living plant display collections at the U.S. National Arboretum by incorporating documented germplasm into the garden. We have added 839 new accessions to the living collections this year. A total of 29,418 living plants comprise the collections managed and are represented by 17,732 accessions. The records for 5,887 accessions were edited. Inventory checks that were deferred are underway with an initial focus on plants in the Asian Collections. More than 200 trees were planted in collections early in the Fiscal Year, and nearly all are growing well. Holdings are available in Germplasm Resources Information Network (GRIN). Many oaks have been lost to rapid decline; a survey of naturally occurring oaks on the USNA campus was undertaken to quantify this problem and elucidate any species differences in symptoms or mortality. Rosemary, dogwood, and Microbiota germplasm is currently being evaluated by nursery industry collaborators. The dogwood selection is resistant to Discula anthracnose and powdery mildew and has potential as breeding stock that may revitalize commercial production of dogwoods. The rosemary has enhanced winter hardiness and may extend the range of cultivation of the species. Surveillance and removal of invasive plants continues to be a focus in preserving gardens, collections, meadows, and woodlands at the U.S. National Arboretum. Under Objective 2, Despite restrictions on in-person programming, more than 500 were reached in virtual programs, including the Lahr Native Plant Symposium and several bonsai programs. Two staff members served as editors of the Herb Society of America Herb Blog, which has been rated the second most popular herb blog on the internet. The Agents of Discovery augmented reality game for youth education continues to attract more users, with approximately 1,000 players using the educational game this year. Staff developed an interactive exhibit to highlight landscape plant choices for landscapes that favor pollinators for the Pollinator Week festivities near the People’s Garden. After two years of hiatus in recruitment of interns and volunteers, a full slate of interns and several new volunteers were onboarded. Under Sub-Objective 2.a. and 2.b., planning has begun on a new exhibit on the site of the former Grass Roots Exhibit to highlight the research mission of the arboretum and provide general orientation to visitors. Work is ongoing to develop and enhance exhibits featuring research in the lobby of the Visitor Center.
Accomplishments
1. Submerged Gravel Wetland Construction and Renovation of Rain Gardens. The construction of a new submerged gravel wetland was completed in collaboration with the District of Columbia Department of Energy and Environment. The new wetland will store and filter runoff and will filter runoff from an area of more than 18.2 acres, including 1.8 acres of impervious surface. The new wetland will allow interpretation of true wetland plants that can be grown in it because it is designed to retain water. Existing rain gardens are not designed to retain water, and sharp variations in soil hydrology within them lead to selection and installation of new plants to better match conditions. This accomplishment is under National Program 301 C4, PS4A.
