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ARS Home » Northeast Area » Washington, D.C. » National Arboretum » Gardens Unit » Research » Research Project #435609

Research Project: Establish and Maintain Public Display Gardens for Woody and Herbaceous Landscape Plants

Location: Gardens Unit

2020 Annual Report

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.

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 29,541 living plants comprise the collections managed and are represented by 17,920 accessions, 12,724 of which are mapped with GPS. The records for 2,569 of these accessions were edited. Holdings are now available in Germplasm Resources Information Network (GRIN). A dwarf evergreen Vaccinium has been propagated for evaluation as a native ground cover and will be trialed in rain gardens. 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. Work focused on removal of woody invasive plants, and more than 1,000 plants were removed. English ivy was removed from more than 300 trees to prevent development of the adult form of the plant that is capable of producing seeds that are the primary means of dispersal. The focus in the Springhouse Run Stream Restoration site shifted to surveillance and removal of invasive plants. The Friends of the National Arboretum used a grant from the District of Columbia government in this effort, assembling a team to combat the invading plants alongside staff and volunteers. Under Objective 2, visitation to the arboretum was greatly impacted by the advent of the coronavirus in what would normally be the peak period for visitation. The new Arboretum App was downloaded by 3,707 users and greatly enhances access to holdings data. 391 people registered for fee-based educational programs that generated nearly $20,000 in income, 77% of last year’s income, despite loss of all revenue from spring programming due to the coronavirus. 469 new display label templates were completed and 558 display label templates were updated. 5,224 images with metadata have been added to Asset Bank; the images are used on the Arboretum App and documentation of plants and events at the arboretum. Work was also begun on signs for the newly created rain gardens in the R Street parking lot. Under Sub-Objective 2.a., Under Sub-Objective 2.b., ongoing support has been provided to researchers in the Invasive Insect Biocontrol and Behavior Laboratory in Beltsville, Maryland, and the Beneficial Insects Research Laboratory in Newark, Delaware, in utilizing the grounds of the USNA for research related to biocontrol of landscape pests.

1. Friendship Garden redesign and interpretation. The replanting of the Friendship Garden was completed. The design is based on an ecological planting scheme aimed at reducing maintenance inputs and enhancing environmental benefits. Interpretive panels that highlight the garden’s positive impact on pollinators and water resources have been completed. This design was funded by the National Capital Area Garden Clubs and is part of a multi-year project to improve the environmental footprint and safety of the Friendship Garden.

2. Nick Lenz Exhibit. An exhibit was developed to highlight the work of Nick Lenz in adapting the art form of bonsai to a non-traditional style. The exhibit is the first national exhibit for this acclaimed bonsai artist and consisted of key works Lenz created that were on loan from their owners. Lenz’s unconventional approach incorporates sculpture and other elements that give his pieces complex meaning beyond that of conventional bonsai.