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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

2021 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 891 new accessions to the living collections this year. Collections consist of 29,101 plants, and the total number of accessions is now 17,568. A total of 6,574 records were edited or updated. Holdings are now available in Germplasm Resources Information Network (GRIN). Novel selections of rosemary, dogwood, blueberry, and Siberian cypress are currently being evaluated by nursery industry collaborators. The dogwood selection is resistant to Discula anthracnose and powdery mildew and offers breeding programs new sources for introgression of these traits into commercial dogwood selections. The rosemary has enhanced winter hardiness and may extend the range of cultivation of the species. The blueberry and Siberian cypress have novel ornamental traits not present in cultivation. Surveillance and removal of invasive plants continues to be a focus in preserving gardens, collections, meadows, and woodlands at the U.S. National Arboretum. Goats are being trialed for incorporation into the management strategy for invasive plants. Plans in the Springhouse Run Stream Restoration site are maturing and the focus continues to center on removal of invasive plant species. Under Objective 2, the coronavirus pandemic led to greatly increased visitation after the arboretum was reopened. The pattern of visitation has shifted to more families with young children and has been more consistent even during the hottest months of the summer and coldest months of winter. The arboretum hosted more than 300,000 visitors during the months of January, February, and March, and the greatest portion of that took place in March. Under Sub-Objective 2.a., the Arboretum App was downloaded by 9,995 users, about one third of the total downloads since its launch in 2017. The app greatly enhances access to holdings data. Stately Treasures, a feature on the app, was developed to interpret all 50 state trees including the District of Columbia. Signs near representative trees on the grounds point the reader to interpretive content for the state trees in the app. Under Sub-Objective 2.b., 208 people registered for fee-based educational programs that generated nearly $7,500 in income. Programming shifted to electronic delivery entirely due to the pandemic, and registration revenues were reduced by two thirds from last year. Ongoing support has been provided to researchers in the Invasive Insect Biocontrol and Behavior Laboratory in Beltsville, Maryland, in utilizing the grounds of the USNA for research related to biocontrol of landscape pests.

1. Acquisition of Kemin Hu stones. A noted collector of Chinese viewing stones, Kemin Hu, transferred much of her collection to the U.S. National Arboretum. Staff are working with the National Bonsai Foundation to produce a catalog of the collection, which consists of more than 100 stones valued at more than $570,000. The stones will be displayed in the National Bonsai & Penjing Museum.