Arboretum Hosts APGA Tour, Reception, and Dinner

More than 500 public garden professionals came to the arboretum on June 29 for afternoon tours and a cocktail reception, and over 400 stayed to attend dinner. The activities were offered as part of the American Public Gardens Association Annual Conference. Afternoon tour stops allowed the group to visit the Native Plant Collections, Asian Collections, and Conifer Collections where staff was stationed to answer questions. During the cocktail reception, the participants could explore the National Bonsai & Penjing Museum, National Herb Garden, National Capitol Columns, Introduction Garden, and Friendship Garden on their own. The Herb Society of America produced posters for the herb garden highlighting their involvement in public gardens throughout the country, and Floral and Nursery Plants Research Unit scientists gave an overview of their newest plant introductions and research in a display near the Administration Building. Bluegrass music and American appetizers and beverages greeted guests at the National Capitol Columns. Several units of the Herb Society of America provided herbal canapés and beverages in the National Herb Garden. The National Bonsai Foundation sponsored Asian refreshments in the National Bonsai & Penjing Museum, where a sampling of books from the National Arboretum Library was available in the International Pavilion. Dinner, sponsored by Bartlett Tree Experts, was served in a tent in the ellipse meadow, and guests enjoyed dessert in the National Herb Garden as a swing band played to close out the evening.

The event provided the arboretum with the opportunity to make public garden professionals throughout the country aware of the extent and quality of its gardens, collections, research, and educational programs. The event would not have been a success without the generous support of Bartlett Tree Experts, the National Bonsai Foundation, Herb Society of America, and the National Capital Area Garden Clubs, Inc.

AGPA members enjoy refreshments and music at the
National Capitol Columns.

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Construction of New Main Entrance in Fern Valley to Begin this Fall

Construction drawings for the new entrance and accessible path system in the Fern Valley Native Plant Collection (Fern Valley) are complete, and construction will take place this fall. The National Capitol Columns and Fern Valley will be linked by a new section of the Flowering Tree Walk. The walk will lead to the new entrance, which will be located between the Old Field Meadow and the Prairie. The swale near the new entrance will be converted to a wetland, complete with a bridge that will allow visitors to see wetland plants without setting foot in the muck. The boardwalk will make a loop through the Prairie. Just beyond the entrance, a new Prairie and Meadow Garden will feature new cultivars of native plants that grow in full sun. A new Woodland Garden already occupies the area formerly devoted to narcissus and ivy collections.

Much of the new accessible path will follow the course of existing paths, and great care will be taken not to damage existing trees. New bridges will be constructed on the upper reaches of Fern Valley, and they will be adorned with rustic woodwork. A new garden shed will echo the rustic quality of the bridges. Benches and railings will be constructed in the same way to give the man-made elements in the collection a consistent look.

These improvements are an important step in expansion of the Native Plant Collections and will complete another segment of the accessible path system identified in the 2000 Master Plan.

Design of the new entrance and accessible trail system in
Fern Valley (click on the image for a larger view).

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Scientist Receives Grant for Easter Lily Research

The Fred C. Gloeckner Foundation, Inc. awarded a grant to Dr. Kathryn Kamo of the Floral and Nursery Plants Research Unit to use genetic engineering to develop resistance to nematodes in Easter lilies. The root lesion nematode is the number one pest of Easter lilies grown in the field, and it ranks third for the damage that it causes to agricultural crops. Dr. Kamo’s work includes isolating genes that affect the development of the nematode and developing Easter lilies with these genes for possible resistance against the pest.

The research project was initiated at the request of Lee Riddle, manager of the Easter Lily Foundation, who says that nematodes are his biggest problem when growing lilies in the field. The project will be in collaboration with University of Leeds scientist Dr. Howard Atkinson, who has demonstrated nematode resistance in several crops using a cysteine proteinase inhibitor gene that he has isolated from rice and modified.

The Gloeckner Foundation awards grants for research and educational projects in floriculture and related fields at universities, colleges, and Federal research institutions in the United States. Kamo’s grant is for one year and $10,000.

Easter lily plant genetically engineered to contain a reporter gene that is used to show that the lilies express the foreign gene.
Easter lily plant genetically engineered to contain a reporter
gene that is used to show that the lilies express the foreign

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Cell Phone Tour Expanded

Visitors to any one of the arboretum’s major gardens and collections will now find stops on the cell phone tour. Staff recorded over 50 stops this spring to expand the tour from the original 10 recorded last fall for the National Herb Garden. Information available at each stop ranges from an introduction to the collection to specific details about a plant.

Up-to-the-minute data about the tour is available to the arboretum through a web site that tracks not only the number of calls, but also how many times each stop is dialed and how many minutes the callers spend listening. The data tell us which stops are most frequently dialed (the herb garden and bonsai museum top the list), and which are not being used very often (perennial and boxwood collections). Interestingly, the data correspond to the results of our 1997 visitor survey. The information will help us to find better placement for the underutilized stops.

Through caller feedback and analysis of the data, we will review the success of this type of tour as we also evaluate its cost effectiveness. The tour is funded through next spring, and may be extended pending the results of the evaluation.

Signs alert visitors to cell phone tour stops in the

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Brochure Now Available for the Friendship Garden

A professionally designed brochure for the Friendship Garden joined the growing “family” of brochures for the arboretum’s gardens and collections. Using a design template that gives a uniform look for all of the brochures, Agricultural Research Service staff created the layout with text and images provided by arboretum staff. It is the first brochure for this collection, and provides information about the garden’s purpose and organization that was previously unavailable to visitors.

The brochure includes a hand-drawn map that matches the style of those already completed for the arboretum’s Visitor Guide and bonsai, azalea, and Asian collection brochures. The maps are based on satellite images, which the artist uses to create an accurately proportioned outline. He then selectively adds the details that will help visitors navigate each collection, often using perspective views to show architectural and garden details. Visitor studies show that many people prefer this type of illustrative wayfinding aid rather than an abstract linear plan.

The National Capital Area Garden Clubs, Inc. generously funded the Friendship Garden brochure. It was the project of last year’s president, Dale DeFeo. The NCAGC is a member of the National Garden Clubs, Inc., which has provided long-standing support for the Friendship Garden.

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Private Events at the National Arboretum Prove Successful

For many years, visitors and callers have asked to use the arboretum’s inviting gardens for their special events. Beginning in October 2006, this wish became a reality. The arboretum has made several outdoor and indoor spaces available for fee-based public use. Recent bookings include a wedding held during the peak bloom of the Dogwood Collection, a party in the meadow, and a meeting in the classroom. Ten more weddings are scheduled through May 2008, and inquiries continue to come in daily.

The eleven available sites and their corresponding fees are listed on the arboretum website under a new web page, Facilities Use. The page includes a copy of the Combined Federal Register, the official document that provides the details of the approved uses of the arboretum’s facilities. The rentable sites include the National Herb Garden meadow, the Administration Building east terrace, and the Friendship Garden. Indoor facilities include the Administration Building lobby, auditorium, and classroom.

Especially in demand is the Dogwood Collection, where the weddings are held. The collection’s beautiful spring display, rich fall color, and year-round natural beauty and serenity make it a perfect setting for a memorable day.

Fees collected from these private events help support the important work of the National Arboretum.

Wedding ceremony in the Dogwood Collection.
Wedding ceremony in the Dogwood Collection.

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Canopy Trees Added to the Flowering Tree Walk

Bartlett Tree Experts staff planted 77 trees along the Flowering Tree Walk in April during the second phase of planting for this new feature on the ellipse meadow. The planting consisted of mainly canopy trees that will grow to shade future shade-loving flowering trees. Arboretum introductions like New World red maple (Acer rubrum ‘New World’) and Jefferson American elm (Ulmus americana ‘Jefferson’) were among the many selections planted. Most of the trees were planted on sections of the Flowering Tree Walk that have yet to be completed. Planting them early allows them to get established before the smaller, shade-loving selections are added, so they will be able to provide some shade.

Keeping the trees alive in this non-irrigated area during the summer drought was a challenge. It took an intern 3 days per week to keep the newly planted trees watered. Initially, the intern was filling the 25 gallon "gator bags" on each tree twice a week using buckets. In August, the arboretum acquired a motorized watering tank by retro-fitting an old spray tank used for pesticides to help the intern water the trees. This new tank reduced the watering of the trees from 5 to 2 hours for each watering.

The Flowering Tree Walk links the major collections on and surrounding the central ellipse. The completed portion of the walk unites the National Capitol Columns, the National Bonsai & Penjing Museum, the National Herb Garden, the Azalea Collections, and the Columns Overlook. An additional piece of the walk will be added when the new entrance to the Fern Valley Native Plant Collection is constructed. Future sections of the walk will join features on the south side of the ellipse, most of which, like a new visitor center, remain unfunded. For now, a mowed path represents the approximate location of the un-constructed phases of the walk.

Each section of the new plantings corresponds to the nearest collection and its existing plant communities. Once the walk is complete and visitors walk it in its entirety, they will experience a glimpse of the adjacent collections.

Bartlett Tree Experts generously donated the labor and expertise of several of its Rockville office employees to complete this second phase planting.

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New Greenhouses Under Construction

The antiquated 1960s greenhouses in the arboretum’s nursery site are gone. Contractors removed the old structures and their foundations and are laying new foundations for state-of-the-art greenhouses. The new greenhouses will support the both the research and the public gardening horticultural programs on the Washington, D.C., campus of the arboretum. A mist system and supplemental bench heating will aid in the propagation of new plants.

This two-million-dollar modernization effort is part of a long-range plan to implement the arboretum’s master plan. Over the coming years, existing facilities will be renovated and new features constructed. Step by step, the arboretum is upgrading and improving the physical features on the grounds, while concurrent efforts are underway to upgrade and improve the living collections and display gardens.

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Outdoor Lighting Improvements Enhance Evening Events

The east patio of the Administration Building is a beautiful spot to enjoy the display of ornamental aquatic plants, koi, and large containers filled with some of the newest varieties of tender plants. It is also a frequent site for late afternoon and evening functions. This fall, new lighting will be installed on the patio to facilitate evening events and to provide lighted access to the Administration Building whenever evening functions are held in the National Herb Garden or the National Bonsai & Penjing Museum. Ornamental pole lights will cast light from their locations in the five existing planter boxes, and new lights will illuminate the stairs to the bonsai museum and the accessible ramp leading to the road. In addition to this work, a new controller will be installed to manage all outdoor lighting in the vicinity of the Administration Building, thus further facilitating evening events. The arboretum is making steady progress towards becoming a more people-friendly location for our visitors and for special events.

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FNPRU Liaison Committee Update

The U.S. National Arboretum Green Industry Liaison Committee was established in January of this year to facilitate dialogue between the Floral and Nursery Plants Research Unit (FNPRU) and the nursery and floriculture stakeholders. The committee consists of eight nurserymen and floriculturists from across the country that are considered leaders and experts in their professions. The committee is chaired by Jerry Blankenship of Little Creek Nursery, McMinnville, Tennessee, and arboretum scientist Dr. Richard Olsen has been selected as the primary contact with the committee. The committee has had two conference calls this summer, followed by a small meeting at the arboretum in July. The committee is following up on the successful stakeholder reception at the 2007 Mid-Atlantic Nursery Trade Show (MANTS) with an expanded reception at the 2008 trade show. The theme for next year’s reception will be “How does your National Arboretum contribute to your nursery” and will reiterate our relevance and important contributions to the industry made by arboretum scientists.

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International Boxwood Symposium Participants Visit Arboretum

The National Arboretum, with its National Boxwood Collection, was a fitting destination for participants of the first International Boxwood Symposium held in Washington, D.C., in May. Lynn Batdorf, curator of the National Boxwood Collection, planned the group’s visit. His itinerary included curator-led tours through the boxwood collection, the National Herb Garden and the National Bonsai & Penjing Museum.

The symposium was special this year because the American Boxwood Society (ABS) invited the French Topiary and Boxwood Society (Association Française pour l’Art Topiare et le Buis) to join them to hold the first International Boxwood Symposium. The event drew 72 attendees—22 from France, 1 from England, and Americans from 10 different states. Batdorf, an active member of ABS, made the arrangements for all of the activities scheduled during the 6-day symposium. In recognition of his efforts, the French boxwood society president, Patrick Salembier, awarded him an Honorary Life Membership.

For over a decade, Batdorf has worked to promote more interaction between the American and European boxwood organizations. He, as well as many board members of the American Boxwood Society, will participate in the French boxwood meeting in May 2008.

Curator Lynn Batdorf in the National Boxwood Collection during the International Boxwood Symposium.
Curator Lynn Batdorf in the National Boxwood Collection
during the International Boxwood Symposium.

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Vibrant Colors Enliven the Morrison Garden

In late April, staff transformed the hill at the bottom of the southwest side of the Azalea Collections’ Morrison Garden into a vibrantly hued, multi-seasonal mixed border. The design focused on varying shades of orange and blue. From pale peach to blood-orange and from soft lavender to cobalt blue, perennials, flowering shrubs and seasonal bulbs provide new interest at this important entrance to the collection.

This is the first step in implementing a plan to add perennial selections to the Azalea Collections. The goal is to extend the bloom season by adding late spring, early summer, fall, and winter interest to complement the already wildly popular spring-blooming azaleas. Visitors will find an appealing floral display here even when the azaleas are not in bloom.

Designing a dually-hued garden posed a challenge, but spring catalogs in hand, staff selected many new, exciting orange- and blue-flowered plants. Some noteworthy selections include two fairly new orange coneflowers, Echinacea ‘Art’s Pride’ Orange Meadowbrite™, and Echinacea Big Sky™ ‘Sunset’; a new, dwarf blue mist shrub named Caryopteris ‘Minbleu’ Petit Bleu™, the cobalt blue-flowered Lobelia ‘Fan Blue’, and a rarely seen, historic selection of the red hot poker flower named Kniphofia ‘Timothy’, which has spike-like blooms the color of a frozen creamsicle. The entire design revolves around a planting of 30 orange-flowered Livin’ Easy™ shrub roses (Rosa ‘HARwelcome’) and two steel-blue switch grass selections, Panicum ‘Northwind’ and ‘Dallas Blues’.

Livin’Easy™ shrub rose ‘HARwelcome’.
Livin’Easy™ shrub rose ‘HARwelcome’.

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Innovative Plantings Now Greet Visitors

The landscape surrounding the arboretum’s Administration Building has been transformed into a welcome mat of garden-worthy plants set into creative designs. Where old turf and more traditional shrub and perennial borders once grew, visitors now find new garden beds and containers with novel plant combinations. The area around the Administration Building is part of the Introduction Garden where arboretum introductions join other garden-worthy recent introductions. Visitors are “introduced” to ways to garden differently through new uses for old plants and materials as well as innovative ways to grow and display plants.

To unify the gardens surrounding the Administration building, staff removed the strip of junipers and redefined the linear beds along the front and to the side nearest the Herb Garden. Groupings of red-flowering shrub roses, woody plants that have colorful foliage or winter interest, and complementary perennials, grasses, and bulbs provide visual unity and all-season interest.

The bank along the sidewalk leading from the parking lot to the building entrance features succulent plants and dry climate and native perennials—all examples of water-wise gardening. The selections include three new Sedum album cultivars, ‘Green Ice’, ‘Orange Ice’, and ‘Red Ice’.

A different, yet similar treatment was used to renovate the kidney bean-shaped bed near the tram kiosk. The space in between the two trees echoes the style of British garden designer Beth Chatto and her love of the low, herbaceous border. A stone-dust path allows visitors to cross through the bed. The spring and summer blooming perennials planted here are not quite as drought tolerant as the water-wise selections; however, they are planted in the same mosaic carpet-like pattern. In keeping with the theme for the Introduction Garden, the plantings include many new varieties.

The bed in the center of the circular drive is also part of the renovation. The Pinus bungeana has been pruned to show off its ornamental bark. The Ilex verticillata cultivars will remain for winter interest. Surrounding plantings of thyme and juniper have been removed and replaced with ornamentally attractive, drought-tolerant succulents like Sedum spurium ‘John Creech’ and Delosperma nubigena ‘Basutoland’, as well as a new planting of Juniperus conferta ‘Blue Lagoon’. The graphic qualities of the stone “river” that runs through the bed will be enhanced by additions to the existing purple and white blazing star (Liatris) planting. Ilex covers the “banks” of a flowing river of purple and white “sticks” of blazing star, which is softened by billowy grasses and Russian sage that echo the colors. The design gives this prominent circle a sense of purpose and unifies it with the other plantings surrounding the building.

All of the renovations fit well into the Introduction Garden theme because the beds feature plants used in ways gardeners are not accustomed. Groups of a new selection of rose called Home Run illustrate how shrub roses can be used effectively as a backbone to enhance plantings of or to replace traditional flowering shrubs. Visitors might also spot common houseplants tucked in among the vibrant container plantings—new life for familiar old friends!

Front of the Administration Building before the renovation.

New plantings in the front of the Administration Building.

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Amber Waves of Grain Appear at the Capitol Columns

A small field of winter wheat carpeted the eastern approaches to the National Capitol Columns this summer. Staff planted the wheat last fall, and the tawny stand of grain remained until early August. The planting began with a re-grading project to smooth out the area within the oval walkway leading to the columns from the Ellipse Road. The intention at that time was to plant the area in turf.

The Friends of the National Arboretum hired landscape architect Reed Hilderbrand to develop a comprehensive planting plan for the Flowering Tree Walk, and in the course of this work, the firm expressed the opinion that mowed turf was not the best aesthetic option in this area because of all the harsh lines, concrete, and stone. They suggested that the area be devoted to plants that are not mowed. Because the soil is very poor, staff planted a winter cover crop of crimson clover to build soil fertility and organic matter and added winter wheat to the mix to help bind the soil and provide some summer interest. The area will be devoted to different agronomic crops or self-seeding annual flowers to give another dimension of interest to the columns.

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Drought Takes a Toll on Arboretum Plants

Throughout this summer’s severe drought, arboretum staff struggled to meet watering needs. Even with a booster pump station to increase water pressure above levels normally found in the municipal water system, pressure was inadequate to keep water flowing in all collections. In July, staff devised a plan to limit the number of spigots open at any given time to ensure adequate pressure.

Even with round-the-clock watering, low humidity and extreme heat combined to make this one of the most severe drought periods the arboretum has experienced. While not yet as prolonged as droughts in 1999 or 2001, it was intense because of the long run of hot days in early August and low humidity during cooler interludes in July and mid-August.

Many trees, including mature white oaks, red oaks, and pines, succumbed to the drought and will need to be removed in the coming months. Staff are developing plans to better integrate the components of the automated irrigation systems on the grounds to make more optimal use of every precious drop of irrigation water.

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Scientists Attend Summer Meetings and Conferences

Several Floral and Nursery Plants Research Unit scientists participated in professional meetings and conferences this summer, sharing information about their research projects.

Dr. John Hammond, Research Plant Pathologist and Research Leader of FNPRU, attended the annual meeting of the American Phytopathological Society (APS) in San Diego, California, July 28-August 1. He presented an invited talk "Utilization of viral genes and regulatory elements for plant biotechnology" in the session “Contributions of Plant Virology to Biotechnology,” and a second invited talk "New and Emerging Viruses of Ornamental Plants – When is Virus Infection a Problem?" in a symposium entitled “Collaboration between Industry and Researchers to Improve Management of Viral Diseases of Ornamentals – a Model for Other Crops.” In addition, he presented two posters: "Molecular characterization and taxonomy of Lolium latent virus, a novel member of the family Flexiviridae" and "Vallota mosaic virus is closely related to Ornithogalum mosaic virus, and distinct from other potyviruses infecting Ornithogalum, Lachenalia, and Cyrtanthus.” Dr. Hammond also participated in the ornamental viral discussion group with other researchers and stakeholders from the floral and nursery industry, and the APS Virology Committee meeting.

Two of the arboretum’s woody plant breeders traveled to Scottsdale, Arizona, in July to attend the annual conference of the American Society for Horticultural Science (ASHS). Dr. Richard Olsen presented a paper on “Open problems in Celtis breeding” (co-authored with arboretum scientist Alan Whittemore), and Dr. Margaret Pooler presented a paper on “Studies of anthocyanin regulatory genes in Phalaenopsis using a transient expression system” (co-authored with arboretum scientists Rob Griesbach and Hongmei Ma). The conference serves as a forum for scientists from diverse horticultural commodities, disciplines, and geographic areas to share and learn about the latest technologies and theories through symposia, colloquia, poster sessions, and short talks. Founded in 1903, the American Society for Horticultural Science is the largest organization in the U.S. dedicated to advancing all facets of horticultural research, education, and application. While in Phoenix, Dr. Olsen visited with George Hull, plant breeder and new product development for Mountain States Wholesale Nursery. Mountain States Wholesale Nursery is one of the largest wholesale nurseries in the Southwest, specializing in southwestern natives, including three genera of interest to research programs at the National Arboretum: Celtis, Cercis, and Chilopsis. The nursery is a new cooperator for the tree breeding program, and will send Chilopsis linearis cultivars to the arboretum for incorporation into its ×Chitalpa breeding program.

Dr. Alan Whittemore, Research Botanist, attended a joint meeting in Chicago of several botanical societies—the American Society of Plant Biology, American Society of Plant Taxonomists, and Botanical Society of America—where he spoke about his research on the genetics of species hybrids in oaks. After the July meeting, he spent two days studying Celtis specimens in the herbarium of Chicago’s Field Museum of Natural History, one of the largest herbaria in the United States. Dr. Whittemore supervises the National Arboretum’s over 600,000 specimen herbarium collection.

Dr. Scott Warnke attended the Molecular Breeding of Forage and Turf conference in Sapporo, Japan, from July 1-7. This conference is the primary international meeting for scientists working on plant species used for forages and turfgrasses around the world. Dr. Warnke presented a poster entitled “Tall Fescue Genetic Diversity Based on SSRs and Flow Cytometry.”

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Scientist Attends International Hydrangea Conference

Dr. Sandra Reed attended the International Hydrangea Conference in Ghent, Belgium, from August 16 – 19. The conference, which was attended by 162 participants from 11 countries, included both scientific and production-related presentations. Dr. Reed presented a talk entitled “Taking Hydrangea arborescens and H. quercifolia One-Step Further.” She also displayed some of her research in a poster presentation entitled “Hybridization of Dichroa febrifuga and Hydrangea macrophylla.” Reed is a Research Geneticist who works at the arboretum’s work site in McMinnville, Tennessee.

The meeting was held at the Ghent University Botanical Garden, at which several European hydrangea breeding companies had their newest cultivars on display. While H. macrophylla is most widely used as a garden plant in the U.S., it is commonly grown as a pot plant or for cut flowers in Europe. Many of the breeders are selecting for flowers that age to an attractive color – which they referred to as a “classic color.” Most of the new European H. macrophylla cultivars have large, sturdy flower heads. For cut flower production, long stems are also an asset. Hydrangea macrophylla plants with bi-colored flowers are also popular in Europe.

The first day of the meeting included two tours. Participants first visited the Kalmthout Arboretum near Antwerp. Several of today’s Hydrangea paniculata cultivars, such as ‘Unique’, ‘Pink Diamond’, and ‘Brussels Lace’, were bred there by Jelena de Belder. While initially a nursery and then a private garden, Kalmthout Arboretum is now owned by the province of Antwerp and is open to the public. The second destination was the Belgium Hydrangea Society collection, housed at Destelbergen. This collection includes over 600 cultivars and species of Hydrangea. While it was past peak flowering time for most of the bigleaf hydrangeas (H. macrophylla), the dried flowers remaining on the plants were very attractive. Panicle hydrangea (H. paniculata) was in peak flower and performed very well in the cool summer weather of Belgium.

While hydrangea breeding programs in the U.S. started only during the last decade, they have been underway in several European countries for over 100 years. However, since most of the European breeding efforts are being conducted by private companies rather than public institutions, few details about their work have ever been published in scientific journals. Attending this meeting allowed Dr. Reed, who is breeding bigleaf and oakleaf (H. quercifolia) for U.S. garden conditions, an opportunity to interact with European breeders and learn more details of their work.

Hydrangea paniculata ‘Phantom’ growing in the Belgium Hydrangea Society collection.
Hydrangea paniculata ‘Phantom’ growing in the Belgium
Hydrangea Society collection.

Bi-colored Hydrangea macrophylla on display during the International Hydrangea Conference.
Bi-colored Hydrangea macrophylla on display during the
International Hydrangea Conference.

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Scientist Presents Research Update at Annual Floriculture Event

Dr. Ramon Jordan was an invited speaker for the OFA-sponsored Ohio Short Course in July 14-17 in Columbus, Ohio. He spoke on newly identified viruses in important floriculture crops such as Angelonia, Calibrachoa, Impatiens, and Verbena, their symptoms, host ranges, and detection methods. While there, Jordan met with four major U.S. growers and a diagnostic lab on the need for new detection technologies for emerging viruses. OFA – an Association of Floriculture Professionals—the group’s official name—evolved from earlier floral groups in Ohio. The OFA Short Course is recognized as the premier educational and trade show event in North America, attracting over 10,000 floriculture professionals. Short courses are brief presentations, which often provide technical updates on critical research, intended to educate professionals.

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Arboretum a Presence at the Southern Nursery Association Research Conference and Trade Show

Arboretum scientists presented talks and staffed a booth at the Southern Nursery Association annual research conference and trade show held August 9-11 in Atlanta, Georgia. Drs. Sandra Reed and Donna Fare presented updates on their plant breeding and nursery production programs. Dr. Reed, Research Geneticist, was co-author on three presentations (“Breeding Intra- and Inter-specific Cornus species”; “Resistance to Powdery Mildew in Hydrangeas”; “Evaluation of Hydrangea Cultivars for Resistance to Powdery Mildew”) and chaired the Growth Regulators section. Dr. Fare, Research Horticulturist, was co-author on one presentation (“Flowering Cycles and Winter Hardiness of Encore Azaleas”). They were joined by Dr. Richard Olsen to help represent the arboretum in the trade show booth, which highlighted recent arboretum plant introductions, including Callicarpa dichotoma ‘Duet’, Lagerstroemia ‘Arapaho’ and ‘Cheyenne’, and Syringa ‘Declaration’ and ‘Old Glory’. The Southern Nursery Association (SNA) Trade Show and Convention was held August 9 – 11, 2007 at the Georgia World Congress Center in Atlanta, Georgia. Products from over 550 exhibitors were showcased. Attendance was estimated at 10,000.

View of arboretum introduction Lagerstroemia ‘Pocomoke’ growing at the Atlanta Botanic Garden.
View of arboretum introduction
Lagerstroemia ‘Pocomoke’
growing at the Atlanta Botanic

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Woody Landscape Plant Crop Germplasm Committee Meets in Oregon

This year’s Woody Landscape Plant Crop Germplasm Committee (WLPCGC) meeting was held in conjunction with the Farwest Trade Show on Aug. 23-24 in Portland, Oregon. Arboretum scientists Sandra Reed, Richard Olsen, and Alan Whittemore represented the arboretum at the two-day crop germplasm meeting. Dr. Reed served as chair. Items discussed included dangers posed to woody landscape germplasm by emerging pests, such as the Emerald Ash Borer, and natural disasters like tornados and hurricanes. The meeting included reports from curators of woody landscape plant germplasm on the status of their collections. Oregon nursery producers, who attended part of the meeting, provided industry input into these issues.

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.

A pre-meeting tour was held on August 22. Participants toured the Landscape Plant Development Center (LPDC) field plots in Aurora, Ore. The director of the LPDC, Dr. Harold Pellett, provided information on LPDC breeding programs. The group then visited the USDA-ARS National Clonal Germplasm Repository in Corvallis, Oregon. Dr. Kim Hummer, Research Leader, organized a tour of the repository, where members heard about germplasm acquisition, storage, disease screening and distribution. The committee toured greenhouses and field plots at the station – and conducted an impromptu blueberry taste test! The final stop on the tour was at Heritage Seedlings in Salem, Oregon. Mr. Mark Krautmann showed members a restoration project that he started a few years ago. The objective of this project is to return native vegetation to 400 acres of oak savannah. The committee also toured the greenhouse operation at Heritage Seedlings.

Oregon has one of the largest nursery production areas in the country, which afforded arboretum scientists the opportunity to visit with stakeholders and industry members. In addition to the visit to Heritage Seedlings, a major bare root liner producer, Olsen and Whittemore traveled to J. Frank Schmidt & Son Co., one of the largest tree nurseries in the U.S., and Cistus Nursery, a mail-order/retail nursery specializing in rare and unusual plants.

Seedling grown red-leaf Japanese maples (Acer palmatum var. atropurpurea) growing at Heritage Seedlings, Inc. in Portland, Oregon.
Seedling grown red-leaf Japanese maples (Acer palmatum
var. atropurpurea) growing at Heritage Seedlings, Inc. in
Portland, Oregon.

Acer pentaphyllum growing as a graft at Heritage Seedlings. This rare Asian species was one of the target plants for arboretum scientist Mark Roh during his expedition to China last fall.
Acer pentaphyllum
as a graft at Heritage Seedlings.
This rare Asian
species was
one of the target plants for
arboretum scientist Mark Roh
during his expedition to China
last fall.

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Small Farms and Beginning Farmers and Ranchers Coordinators Group Visit

The Floral and Nursery Plants Research Unit (FNPRU) is collaborating with Tennessee State University on an 1890 Land-grant project to increase small farmers’ awareness and adoption of biotechnology-based products using on-farm demonstration and information dissemination. One of the outcomes of this collaboration was a visit and tour of the Henry A. Wallace Beltsville Agricultural Research Center in June by the Small Farms and Beginning Farmers and Ranchers Coordinators group. This group is a USDA–wide working group addressing issues of small farmers and beginning farmers and ranchers and was established to coordinate, advocate, and facilitate implementation of policies and programs. Their visit to Beltsville included a tour of the FNPRU labs and greenhouses.

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Carley Assumes Management of Conifer Collections

Arboretum IPM Specialist Christopher Carley took over management of the Conifer Collections in June. The curator position for the collection has been vacant since Susan Martin retired after more than 30 years of service in January. Due to budgetary constraints, the arboretum will not be able to fill the curator position. Carley will provide oversight for the gardening staff who will maintain the collection. Carley also manages greenhouse and nursery spaces at the arboretum and has responsibility for automated irrigation systems on the grounds. He will be well served by his keen interest in conifers; they were a major part of his landscape in California. A new horticulturist will be recruited for the Conifer Collections when the new fiscal year arrives in October.

Martin also had responsibility for the maintenance of the Dogwood Collection and the Maple Collection. The Dogwood Collection will now be curated by Native Plants Curator Joan Feely. Boxwood Curator Lynn Batdorf will curate the Maple Collection.


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Taxonomy Program Gains New Employees

Recent restructuring in the Agricultural Research Service’s Beltsville Area Research Center (BARC) resulted in a boon for the arboretum’s taxonomy program with the arrival of four new employees. The National Arboretum is part of BARC.

The arboretum’s herbarium collections manager position had been vacant since last fall, with the duties filled for the short term by Mike Cagley, a longtime USDA employee who most recently worked in the Germplasm Lab in Beltsville. He has now been assigned permanently to the position.

Louise Riedel, a taxonomy support scientist, retired earlier this year after 17 years at the arboretum. She had worked closely with Dr. Frank Santamour on a variety of tree research projects. To take her place, Zheng-Lian Xia joins the group from Beltsville’s Soybean Genomics Lab.

Two new scientists represent a growth in the taxonomy program. Dr. Joseph Kirkbride, a research scientist, left the Systematic Botany and Mycology Lab to conduct research at the arboretum on Catalpa and Chionanthus, two genera of woody ornamentals. Kirkbride also curated the USDA Seed Herbarium for many years. This is a collection of seeds of about 130,000 species used for seed identification and research on seed morphology. The seed collection will be moved to the arboretum, where it will be located alongside the National Arboretum Herbarium. Although Joe is new to the arboretum, he sees a familiar face here—he and Director Thomas Elias were once students together at St. Louis University.

Dr. Robert Webster, a grass specialist, has moved from the Germplasm Lab and will be working primarily with the herbarium database. He will also work to curate and expand the herbarium collection of ornamental grasses.

From left to right: Zheng-Lian Xia, Robert Webster, and
Joseph Kirkbride.

Mike Cagley

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Summer Interns Offer Fresh Ideas, Valuable Labor

Six interns worked alongside arboretum staff from May into August, contributing much needed assistance in the gardens and in the lab. Selected from a pool of applicants, the students gained 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 pertain to the individual’s professional interests. Their projects ranged from mapping the newly planted trees in the flowering tree walk to assisting with tissue culture. The group’s horticultural efforts in the collections and gardens helped make the end-of-June visit to the arboretum by hundreds of public garden colleagues a success.

For the first time, this fall the arboretum will offer two full-time, year-long internships at the GS-5 level. Staff learned that the higher pay was essential in order for quality candidates to afford to spend 12 months in the D.C. area. The new positions will be in the Asian Collections and the National Herb Garden.

Many of the internship positions are funded by generous donations from stakeholder groups. The Potomac Unit of the Herb Society of America (HSA) and the HSA fund the National Herb Garden intern; the Woman’s Farm and Garden the Dogwood Collection intern; a private donor the Asian Collection intern; the National Garden Clubs, Inc. the Friendship Garden intern; and the Friends of the National Arboretum the Flowering Tree Walk intern.

2007 interns pictured from left to right: Laura Grieneisen (Introduction Garden), attending the College of William and Mary where she is a herbarium assistant; Kimberly Zitnick (Flowering Tree Walk), graduated in May 2006 with a B.S. in Biology from St. Mary’s College of Maryland; Gregory Nebelecky (Shrub Breeding Program), attending the State University of New York, College of Environmental Science and Forestry with a major in Biotechnology; Joseph Meny (Dogwood Collection), attending the University of Maryland as a landscape architecture student; and Gwendolyn Bagley (Fern Valley Native Plant Collection), graduated in May 2005 with a B.A. in Political Science from St. Mary’s College of Maryland, where she took classes in sustainable development and environmental economics. Not pictured: Megan Nortrup (Friendship Garden), graduated in 2000 from the University of Maryland with a B.S. in Geography and a B.A. in Music.
2007 interns pictured from left to right: Laura Grieneisen
(Introduction Garden), attending the College of William and
Mary where she is a herbarium assistant; Kimberly Zitnick
(Flowering Tree Walk), graduated in May 2006 with a B.S.
in Biology from St. Mary’s College of Maryland; Gregory
(Shrub Breeding Program), attending the State
University of New York, College of Environmental Science
and Forestry with a major in Biotechnology; Joseph Meny
(Dogwood Collection), attending the University of Maryland
as a landscape architecture student; and Gwendolyn Bagley
(Fern Valley Native Plant Collection), graduated in May 2005
with a B.A. in Political Science from St. Mary’s College of
Maryland, where she took classes in sustainable development
and environmental economics. Not pictured: Megan Nortrup
(Friendship Garden), graduated in 2000 from the University
of Maryland with a B.S. in Geography and a B.A. in Music.

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Last Updated   September 21, 2007 9:26 AM