Research Unit Releases New Viburnum

The National Arboretum’s shrub breeding program introduced its 20th new viburnum cultivar this summer. Called ‘Nantucket’—in keeping with the series’ Native American names—the plant was selected for its many outstanding features: large, mildly fragrant white inflorescences; dark semi-evergreen narrow leaves; and upright relatively compact growth habit. Maturing at 12 feet high by 7 feet wide, ‘Nantucket’ makes an impressive specimen plant. It is also suitable for hedge or mass plantings, or as a backdrop in the shrub border. Click here for a detailed fact sheet.

‘Nantucket’ originated from a cross made in 1988 by the late arboretum scientist Donald Egolf. He used ‘Eskimo’ as the seed parent combined with pollen from a species collected in the wild from China, Viburnum macrocephalum f. keteleeri. After noteworthy performance in the National Arboretum’s research fields, the selection was sent for further evaluation to cooperators in Alabama, Georgia, Illinois, Maryland, Massachusetts, Michigan, New Jersey, Ohio, Oregon, Tennessee, Texas, Virginia, Washington, and West Virginia. Based on production and landscape performance at these sites, ‘Nantucket’ was named and released by the Agricultural Research Service in July 2008. Wholesale cooperators are currently propagating ‘Nantucket’ for expected retail availability as early as Spring 2009.

The arboretum is no longer actively breeding viburnum; however, there are still several promising selections in the pipeline that are in various stages of evaluation.

Viburnum ‘Nantucket’ in full flower.
‘Nantucket’ in bud.
Viburnum ‘Nantucket’ in full flower. ‘Nantucket’ in bud.

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New Arboretum Posters Highlight Introductions

With support from the Friends of the National Arboretum and design expertise from ARS’s Information staff, the National Arboretum created three full-color posters that feature some of its best woody plant introductions. One poster presents the arboretum’s superior tree introductions, while a second one focuses on its most outstanding shrub cultivars. The third poster is devoted solely to the arboretum’s well-known crapemyrtle introductions. The posters were designed to help inform growers, retailers, and the public about the results of the arboretum’s tree and shrub breeding programs. They will be distributed to stakeholders at trade shows and other industry functions, but may also be downloaded from the arboretum website.

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China Garden Project Receives Green Light

Earlier this year, Congress passed a comprehensive Farm Bill giving the U.S. Department of Agriculture authorization for all of its programs and activities. Included in the bill was the authority to build the proposed China Garden at the U.S. National Arboretum using appropriated and/or privately donated funds. While no funds were provided in the bill for the garden, it marks another milestone in this ambitious project and clears the way for the arboretum to once again seek and receive funds from the public.

The China Garden is a classical Chinese garden located on 12 acres within the National Arboretum and consists of three major sections containing 22 structures, a 1.7 acre lake, several smaller ponds, trails, and several pavilions. This is a joint project between the Chinese Academy of Forestry and the U.S. Department of Agriculture. In 2004, Secretary of Agriculture Ann Veneman signed a Memorandum of Understanding with the Chinese government for this garden. The Chinese side will provide the basic design, all structures, furniture, art work, and the rockeries, while the U.S. side is responsible for preparing the site work, all utilities, foundations for the buildings, and maintaining the garden once it is completed.

The conceptual plan for the China Garden has already been approved by the National Capital Planning Commission and the U.S. Commission of Fine Arts. The conceptual plan has been incorporated into the arboretum’s Master Plan. To date, the USNA has received over $324,000 in private donations for this garden and is now accepting additional support from the private sector.

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Arboretum Opens Power Plants and Hosts BEAD II Events

The National Arboretum opened a new garden exhibit and hosted displays from universities and colleges working on energy issues during the Department of Agriculture’s second annual Bio Energy Awareness Days (BEAD) in June. The festivities included an invitation-only reception, educational displays under a large tent in the meadow, and the official ribbon cutting for the Power Plants exhibit. Power Plants is a display of 21 different plants that may be used for fuel.

Twenty-six colleges and universities from Hawaii to Florida participated in a three-day exhibit displaying their research and designs on agriculture-based renewable energy topics. Visitors were treated to a wide range of creative solutions to the country’s energy needs: Penn State brought a Nittany Blue New Holland tractor that runs on 100% biodiesel. The University of Georgia demonstrated biodiesel and ethanol processes with an autonomous biofuel sipping tractor. A trailer from Auburn University demonstrated a mobile biomass gasification and combined heat and power generation unit.

During a reception held on Friday, June 20th, approximately 250 guests toured the exhibits and the Power Plants garden. Dr. Gale Buchanan, Under Secretary for Research, Education and Economics, was the featured speaker during a recognition ceremony honoring the university exhibitors. Other speakers included USDA Under Secretary Dorr and Duane Acker, President Emeritus of Kansas State University and member of the 25×25 Alliance Steering Committee.

A ribbon cutting ceremony officially opened the arboretum’s Power Plants exhibit on Saturday, June 20th. Arboretum Director Dr. Thomas Elias welcomed visitors to the early afternoon event during which Under Secretary Buchanan; Raymond L. Orbach, Director, Office of Science, Department of Energy; and R. Bruce Arnold, Consultant Biomass Utilization for Pulp and Paper, Director of Pulp Assets, Scott Paper Company, and member of the 25×25 Alliance Steering Committee, spoke about the need for alternative energy solutions. Following the ceremony, guests enjoyed ice cream while they toured the exhibit. Family activities included a seed matching game and an opportunity to crush some of the Power Plants’ seeds to extract their oil. See below for a related article on the maturing of the crops through the summer months.

Members of the press attended a special media briefing and preview tour for the Power Plants garden on Friday, June 19th. Dr. Buchanan, Dr. Elias and Gardens Unit Leader Scott Aker offered representatives from broadcast, print, and web-based media organizations tours of the garden as well as in-depth perspectives on its design and on USDA’s on-going biofuel research efforts.

BEAD is an annual celebration held on the summer solstice to increase awareness and knowledge about alternative sources of energy and to offer information on how efficient use and conservation of energy benefits rural communities and the nation.

From left, Raymond L. Orbach, Dr. Thomas Elias; Dr. Gale Buchanan; and R. Bruce Arnold are poised to officially open the Power Plants exhibit. Auburn University’s mobile biomass gasification and combined heat and power generation unit.
From left, Raymond L. Orbach, Dr. Thomas Elias, Dr. Gale Buchanan, and R. Bruce Arnold are poised to officially open the Power Plants exhibit. Auburn University’s mobile biomass gasification and combined heat and power generation unit.

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Power Plants Exhibit Crops Reach Maturity

Frequent rain and warm weather contributed to the rapid growth of nearly all the crops growing in the Power Plants—Farming Energy exhibit. With few exceptions, all the crops grew well, with some, like mustard, sunflower, and corn, even reaching the point at which they would be harvested if they were growing on a farm. The sorghum continues to amaze as it reaches well above twelve feet, and the sugar beets are steadily growing larger as evidenced from the increasing girth of their sugar-storing roots.

Most of the crops will remain in place throughout the winter, and will not be cleared from the site until early spring arrives and it is time to replant them. Early maturing crops such as canola, mustard, and barley, are very tolerant of cold and will be planted again this fall. The tropical species—African oil palm and jatropha—will be moved to the greenhouse for the winter.


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Rare Oconee-bells Seed Collected by Arboretum Staff

Gardens Unit staff Joan Feely, Christopher Upton, and Jeanna Ragsdale headed south to collect seeds of the rare Oconee-bells, Shortia galacifolia, in early June. They traveled to Devil’s Fork State Park, South Carolina, and to Transylvania County and a location near Graveyard Mountain in North Carolina. Despite the foreboding place names, the group had great luck connecting with local experts and finding seed-rich plants.

Two purposes drove this very specific collecting trip. The first goal was to collect seed to grow new plants that would replace the ailing Oconee-bells now growing in Fern Valley. The second goal was to improve the genetic diversity of Oconee-bells under cultivation. Almost all the Shortia growing in American gardens originated from one population in northwest South Carolina until it was flooded by the damming of the Keowee River in the early 1970s. Thousands of plants were rescued from the site and distributed throughout the country; they constitute the genetic material in most gardens today.

Oconee-bells is a beautiful and rare evergreen perennial that only grows naturally in the mountains near the juncture of Georgia, South Carolina, and North Carolina. The plants usually grow in the shade of rhododendrons in rich deciduous forest, notably at the very edges of streams and on seeping slopes.

Oconee-bells are short-lived seed that lose viability shortly after they ripen or if they dry out. A sampling of the collected seeds went to the National Center for Genetic Resources Preservation in Fort Collins, Colorado, in order to see if cryo-preservation might be a solution for Shortia seed storage. The balance of the seed was sown at the arboretum, where the seedlings are growing well.

Oconee-bells flowering in Fern Valley. Shortia galacifolia with fruiting stems in South Carolina. Intern John McCarthy completes the weekly germination tally of Shortia seeds.
Oconee-bells flowering in Fern Valley. Shortia galacifolia with fruiting stems in South Carolina. Intern John McCarthy completes the weekly germination tally of Shortia seeds.

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New Wetland Created in Native Plant Collection

In addition to new paths, Fern Valley’s improvements include a wetland plant habitat near the newly constructed entrance to the Native Plant Collection. Natural surface runoff will flow into the wetland where it will have a chance to infiltrate and replenish groundwater; and it will be cleaned of any sediment or pollutants. This summer, staff planted native species such as bulrush, Joe-pye weed, blue flag, and boneset along with grasses and sedges. While the wetland plants take hold, water will be piped around the site to prevent the plants from washing out in a torrential rainstorm.

A wide boardwalk straddles the wetland and will allow visitors to pause and admire the textures and diversity of the native wetland plants. It connects the main path with the loop of path that invites visitors to explore the prairie section of the collection. A ditch previously ran across the site and afforded few opportunities for the display of native plants that grow in moist or aquatic environments.

A board walk runs through the environmentally sensitive site, which is protected from erosion with coir fabric. Gardener Chris Upton and Fern Valley intern John McCarthy plant through the wet meadow’s erosion fabric.
A boardwalk runs through the environmentally sensitive site, which is protected from erosion with coir fabric. Gardener Chris Upton and Fern Valley intern John McCarthy plant through the wet meadow’s erosion fabric.

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Gypsy Moth Damage Averted

In early May, just under half of the arboretum’s 446-acre campus was sprayed for gypsy moths. Specially trained applicators sprayed Dimilin onto the tops of the trees from a helicopter. This pesticide, an insect growth regulator, is a common choice because it provides effective control in a single application and is effective in small amounts. The arboretum collaborated with Andrews Air Force Base to plan the spraying. A site in the meadow near the National Grove of State Trees provided the staging area for filling the helicopter’s tanks with pesticide. Signage as well as the early morning timing for the application assured the safety of staff and visitors.

Staff felt that spraying was critical this spring because egg mass surveys last fall indicated that the arboretum woodlands were at risk; in some cases, egg mass numbers were more than ten-fold greater than the threshold known to result in severe defoliation. Last year’s drought combined with defoliation this year would undoubtedly have resulted in the death of many large trees in forested tracts of the property. Integrated Pest Management staff will continue to monitor gypsy moths on the property.

The helicopter refills its spray tanks from a tank truck parked in the arboretum’s ellipse meadow. A low-flying helicopter delivers pesticide to the tops of the trees in the designated spray area.
The helicopter refills its spray tanks from a tank truck parked in the arboretum’s ellipse meadow. A low-flying helicopter delivers pesticide to the tops of the trees in the designated spray area.

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Woody Plant Advisory Group Meets at the USNA

The annual Woody Landscape Plant Crop Germplasm Committee (WLPCGC) meeting was held at the National Arboretum this year. The WLPCGC is a national working group that provides analysis, data, and recommendations to the USDA-ARS National Plant Germplasm System on genetic resources of temperate and tropical woody landscape plants. Members include representatives from Federal and State institutions, the nursery industry, botanical gardens, and arboreta. Drs. Richard Olsen, Sandra Reed and Alan Whittemore represented the National Arboretum.

Twenty members attended the 2008 meeting, which was held on June 11 – 12. The meeting included reports from curators of woody landscape plant germplasm on the status of their collections. Items discussed included invasive plant issues and the increased need to conserve native ash germplasm in light of dangers posed by the Emerald Ash Borer. Mark Bohning of the USDA-ARS National Genetics Resources Program provided a hands-on demonstration of the public interface of the Germplasm Resources Information Network (GRIN). At the end of the day participants toured the arboretum grounds.

During a pre-meeting on June 10, committee members toured the National Plants Materials Center, which is part of the USDA Natural Resources Conservation Service, in Beltsville. The group then went to the South Farm in Beltsville to visit the National Plants Germplasm Respository.

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Service Groups’ Many Hands Accomplish Important Work

When it comes time to tackle the removal of invasive vines or the spreading of large quantities of mulch, arboretum staff welcomes extra hands. While the arboretum’s dedicated force of regular volunteers helps keep the grounds beautiful on a day-to-day basis, large-scale, one-time projects are best accomplished by volunteer groups. Each year, a number of organizations offer their members’ services for one-time service days. The Gardens and Research Units have projects planned and waiting for them. Since May, six groups—some having up to 50 volunteers—have helped to remove invasive English ivy, bush honeysuckle, stilt grass, and a variety of vines; and to spread tons of mulch. The groups ranged from the staff of businesses to students from educational institutions: Independent Sector, AARP, Potomac School, Herb Society of America, Global Peace Festival participants, and Georgetown Law School. Their efforts this year resulted in a combined donation of 618 volunteer hours with an estimated value of $12,057.18.

Georgetown Law School students remove vines from the fence around the greenhouse structure.
Georgetown Law School students remove vines from the fence around the greenhouse structure.

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Stakeholders Provide Valuable Funding for 2009 Interns

Again this year, generous donations from several stakeholder groups enabled the National Arboretum to hire talented interns. The Woman’s National Farm and Garden Association, the National Capital Area Garden Club, Inc., and the Herb Society of America sponsored interns in the Dogwood Collection, the Friendship Garden, and the National Herb Garden, respectively, as they have for many years. In addition, the Friends of the National Arboretum created the FONA Internship Program with funds that supported 5 intern positions this year. They have committed equivalent funds for 2009.

Selected from a pool of applicants, the interns represent budding horticulturists and scientists who wish to gain practical experience in one of the top public gardens and research facilities in the nation. Each intern worked on a project that would benefit the institution and complement the individual’s professional interests. This year’s projects ranged from creating a kid-friendly demonstration on biofuels to drafting landscape improvements to the overlook in the Dogwood Collection. In addition to their projects and plenty of hands-on experience, the students joined other horticultural interns from the Smithsonian, American Horticultural Society, Brookside Gardens, National Cathedral, and the US Botanic Gardens, on behind-the-scenes tours of the area’s great gardens.

Intern class of 2008, standing from left to right: Nick Morrissey (Conifer Collections) from Towson, Maryland, is studying Landscape Architecture at the University of Maryland; Matt Martin (summer gardener) from Ohio, who recently graduated from Kent State University with a Bachelor’s degree in Conservation; John McCarthy (Fern Valley Native Plant Collection) originally from Ireland, holds a certificate of Landscape Management from the University of Massachusetts and is studying Landscape Architecture at the University of Maryland; Paul Guilfoy (Flowering Tree Walk) from St. Louis, Missouri, is studying Agri Business with an emphasis in Horticulture at Southeast Missouri State University; Siobhan Burrell (Friendship Garden) lives in Falls Church, Virginia, and holds a certificate in Landscape Design from the George Washington University. Sitting from left to right: Kimberly Zitnick (Asian Collections) from California, Maryland, holds a Bachelor’s degree in biology from St. Mary’s College and will be pursuing a Master’s in Soil Science this fall at North Dakota State University; Amanda Nuckolls (Introduction Garden) from Barboursville, Virginia, plans to return to school in the pursuit of a horticultural degree; Kelly Oklesson (Dogwood Collection) from University Park, Maryland, is studying Landscape Architecture at the University of Maryland; Katrina Emery (Shrub Breeding Research) from Rockville, Maryland, is studying Plant Science at the University of Maryland; Jeanette Warriner (National Herb Garden) from Yellow Springs, Ohio, is Certified as a Nursery Technician by the Ohio State University; Rebecca Roa (Power Plant Exhibit) from Falls Church, Virginia, is studying Agricultural Management at the Virginia Polytechnic Institute.

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Last Updated   October 14, 2008 11:23 AM