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ARS Home » Northeast Area » Washington, D.C. » National Arboretum » Gardens Unit » Research » Research Project #418110


Location: Gardens Unit

2013 Annual Report

1a. Objectives (from AD-416):
The nursery and landscape maintenance industry is the most important segment of agriculture in many areas. Nursery crops provide high-value alternatives to field crops where land prices require a high return. There is increasing interest in the aesthetic and economic value of landscapes that increase quality of life and property values. There is a need to increase the diversity of plant materials in landscapes to realize their full environmental benefit. The nursery industry must continue to offer new and improved ornamental plants to retain economic viability. The landscape maintenance industry must offer clientele services that provide better environmental stewardship. Objective 1: Expand, establish, maintain, trial, document, and interpret living collections of woody and herbaceous landscape ornamentals with high aesthetic, scientific, and educational value, and that reflect current relevant ARS horticultural research programs as appropriate; Objective 2: Incorporate optimal environmentally-sound horticultural practices that increase overall garden management efficiency, and develop integrated pest management strategies and technologies for ornamental plants, especially those suited to the environment of the national capital; Objective 3: Disseminate scientific and practical information to floral and nursery crop industries, public gardens, the increasing number of visitors to the U.S. National Arboretum and its web site, and the general public interested in gardening; Objective 4: Distribute to and exchange with the horticulture industry and collections new and unusual landscape plants.

1b. Approach (from AD-416):
A unified Collections Policy will be developed to provide a framework for identifying the objectives of each plant collection and display garden on the campus of the USNA. Existing collections will then need to be evaluated against this collection policy and a multi-year Plant Acquisition Plan will be developed for each collection to guide development. New ornamental plants will be procured from industry leaders in ornamental plant introduction efforts. Existing Glenn Dale azaleas in the holdings of the Azalea Collection will be propagated and used to replace Glenn Dale azaleas of unknown identity. Native flora will be collected. The Flowering Tree Collection, Holly Magnolia Collection, Conifer Collection and collections of penjing in the National Bonsai and Penjing Museum will be augmented by incorporating a wider variety of plants. The current Power Plants exhibit site will be used to highlight ARS accomplishments. Staff will continue to utilize IPM in management of their collections and will incorporate other technologies such as solar power, green roofs, rain gardens, and water wise gardens as funds allow. Program ideas will be developed in collaboration with the Educational Programs Coordinator. Plants with superior landscape attributes within existing collections will be propagated for distribution and evaluation in collaboration with Floral and Nursery Plant Research Unit efforts.

3. Progress Report:
Grass Roots Exhibit The Gardens Unit is providing leadership for the Grass Roots Initiative and is preparing the site. The National Turfgrass Federation is the main partner in Grass Roots. Groundbreaking is scheduled for November 15 and a spring opening is planned. Plant Collections Committee New policies for collections have been developed and implemented with the establishment of an Arboretum-wide Plant Collections Committee (PCC) as specified by the recently developed Living Collections Policy. The PCC is involved in pursuing the first review of a North American Plant Collections Consortium collection, the National Boxwood Collection. Crapemyrtles will be nominated to become an NAPCC. Collection Development Plans arealso being developed for all collections. National Boxwood Collection Used for Boxwood Blight Research The germplasm in the National Boxwood Collection is being utilized by USNA and ARS scientists and by others seeking germplasm resistant to Boxwood Blight for efforts to develop resistant boxwood. The existing collection is being protected by a rigorous quarantine program. Renovation of the Glenn Dale Azaleas HPRL funds were used to remove 450 sapling trees on the Glenn Dale Hillside of the Azalea Collections to create better light conditions for the azaleas growing there. Azaleas were pruned to stimulate new growth. Invasive Species Management HPRL funds were used to remove invasive plants from the Glenn Dale Hillside portion of the Azalea Collections. ASRTs are working to combat invasive plants in specific zones of the USNA grounds and are monitoring cleared parcels to prevent reestablishment. Introduction Garden Improvements The North Court area in the Introduction Garden was abandoned during the renovation of the Administration Building that was completed in 2013. A site for a tent is being developed in the North Court. National Herb Garden Renovations The service area for the National Herb Garden is being expanded and the service roadway will be shifted to limit its visual impact. Wood trellises and wood benches will be replaced. Flowering Tree Walk Completion FONA has provided funding for construction of the remaining section of the Flowering Tree Walk that will further enhance visitor accessibility to collections. Introduction Garden Pool Renovation The aquatic garden in the Introduction Garden is being renovated and new bridges will be installed to improve visitor accessibility. Maintenance will be simplified and the design will provide new areas for wetland plants that will also serve to cleanse the water of excess nutrients. Springhouse Run Stream Restoration and R Street Parking Lot Retrofits Archeological investigation and contractual difficulties have delayed progress on the design. Construction will begin sometime in the first half of 2014. Invasive Insect Pest Monitoring Gardens Unit staff have been trained to detect key invasive pests such as the emerald ash borer through the Sentinel Plant Network of the American Public Gardens Association.

4. Accomplishments