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Spring 2014

Spring 2014


leaves Spring 2014

Cait Anastis, Editor Jackie Klisuric, Graphic Design

administration Clement W. Hamilton President and CEO Jim Ansberry Director of Finance David Burke Research Department Chairman Roger Gettig Director of Horticulture and Conservation Brian Parsons Director of Planning and Special Projects James F. Pelowski Interim Director of Development Paul C. Spector Director of Education and Public Programs Nancy Spelman Director of Human Resources and Safety


board of directors JACKIE KLISURIC



4 6 Holden Stream Project 10 Holden Announces Change 11 Volunteers 15 Horticulture Science Center and the U.S. 16 Holden Forest Service

8 9 Bird Bio 12 Plant This, Not That 17 Ask Greg 18 Research 19 Shorts

Donors Help Make 2013

A Magical Year at Holden

Restores Floodplain

New Admission, Membership Rates

Featured Opportunities 20th Anniversary

Working Together

Plant Profile

Erica and Calluna

Louisiana Waterthrush

Phalaris arundinacea

News and Highlights

Paul R. Abbey, Chairman Jonathan E. Dick, Vice Chairman Robert R. Galloway, Vice Chairman Sarah L. Gries, Vice Chairman Joseph J. Mahovlic, Vice Chairman C. W. Eliot Paine, Vice Chairman Stephen J. Knerly, Secretary Thomas D. Anderson Barbara Brown Christopher A. Cullis Peter S. Hellman Michael C. Marino Cynthia A. Moore-Hardy Ellen W. Jones Nordell

Robin Schachat Lynn C. Shiverick K.K. Sullivan Timothy L. Swanson Michael T. Victor Ann T. Whitney

directors emeriti Constance Norweb Abbey Ralph W. Abelt Jeanette Grasselli Brown Miriam N. Gale Henry R. Hatch Arlene M. Holden-Loftin

T. Dixon Long Henry L. Meyer III William J. O’Neill Jr. John Sherwin Jr. Penelope Theis

honorary directors Anne M. Clapp Mary Groves Alison C. Jones Thomas W. Seabright

Volume 111, Number 2 ©The Holden Arboretum

On the Cover: Malus ‘Indian Summer’ in Holden’s Crabapple Collection

Leaves (ISSN 0518-2662) is a class and events magazine published quarterly by The Holden Arboretum for $10 per year for members (included in membership fee) and $50 per year for nonmembers Periodicals postage paid at Mentor, Ohio


Postmaster: Please send address changes to Leaves: The Holden Arboretum, 9500 Sperry Road, Kirtland, Ohio 44094-5172



from the president Once again our busy spring season beckons – and won’t it be fun to see how the Paine Rhododendron Discovery Garden and Norweb Tree Allée look in their second year, especially with the more than 55,000 bulbs planted in the allée last fall? As you will read in this issue of Leaves, the rest of our New Leaf phase one projects are well underway in planning and execution – including the deer fence, canopy walk and Corning Lake/Lotus Pond restorations, plus the creation of a new Streamside Meadow Garden connecting the two. And already people are starting to ask, “What’s next?” None of this would be possible without your support as members, donors and volunteers. Our fundraising optimism, which might have seemed a stretch in the dark economic days of 2008-09, has proven to be justified, as so many of you saw the value of taking Holden to the next level of beauty and public service, and invested in Holden’s bright future. Again, thank you! Looking outside Holden’s boundaries, another big thank you is due to all the volunteers, both individuals and nonprofit organizations, who do so much to promote the themes and societal objectives we hold dear, particularly the sustainable, long-term conservation of our region’s biological diversity and natural resources. Volunteer efforts are especially crucial in these challenging times in which many government agencies at all levels are applying less and less resources to environmental protection.

As much as we enjoy touting Holden’s successes, it is worth applauding the efforts of so many other volunteers and paid staff – naturalists, tree commissioners, teachers, birders, arborists and horticulturists – who, working alone or through various nonprofit or governmental organizations, foster our shared vision, in which “trees, forests and gardens provide maximum ecological and social benefits to our region’s people and communities.” In this issue you also will read about our impending changes to Holden’s membership and admission fees and structures. Even as we are updating our fees (for the first time in anyone’s recent memory), we seek to encourage membership, maintain fees that still are lower than almost all our peer institutions, promote youth and family visitation, and support our ever-growing, mission-driven programs and visitor amenities. I hope you’ll agree we’re still the best deal in town, both for our guest experience and for our service to our region’s communities.

Clement W. Hamilton, PhD President and CEO

Spring 2014


A case in point is Ohio’s well regarded Natural Areas and Preserves program, which was run for many years by longtime Holden friend and Council member Guy Denny.

When the Division of Natural Areas and Preserves, within Ohio Department of Natural Resources, was reorganized in 2011, it left many rare plants, animals and ecosystems without their prior levels of dedicated protection. Guy and other volunteers responded by creating a nonprofit support organization called the Ohio Natural Areas and Preserves Association (ONAPA), to provide volunteers to help maintain and protect those crucial natural areas. Threats from invasive plants, animals and other sources of environmental degradation do not take vacations; and ONAPA and other volunteer organizations are striving to reduce the potential ecological damage.


Donors Help Make 2013

a Magical Year at Holden by Jim Pelowski, interim director of development

Because of strong board and volunteer leadership and the generosity of almost 400 donors, the first phase of the New Leaf Capital Campaign came to a successful conclusion Dec. 31, 2013. At that point, The Holden Arboretum had received almost $9.0 million in gifts and pledges, surpassing the goal of $8.5 million. Projects completed thus far are the renovation of the Warren H. Corning Library, improving the water quality in the irrigation system, and the openings of the R. Henry Norweb Jr. Tree Allée and the Eliot and Linda Paine Rhododendron Discovery Garden. These are outward and visible signs of the generosity and commitment of Holden’s donors. On the schedule for 2014 is the renovation and reshaping of Corning Lake, connecting it to Lotus Pond with a meandering stream and meadow garden paralleling the Norweb Tree Allée. Deer fence will be erected surrounding the 240 acre core garden area providing year-round protection for Holden’s tree and plant collections. And, the exciting tree canopy walk and emergent tower will be constructed.







Many amazing and wonderful gifts gave donors an opportunity to add their names to specific garden areas, to special locations, ponds, even an island in Corning Lake. The naming gift for the canopy walk and emergent tower was a capstone event for Holden and the capital campaign. The Judy and Maynard H. Murch IV Canopy Walk is anticipated to be completed this fall or next spring. All of us will have the opportunity during the summer of 2014 to watch the canopy walk rise 65 feet above Pierson Creek, extending hundreds of feet through the tree canopy and over the ravine, with the entry point in the Helen S. Layer Rhododendron Garden. An emergent tower will rise above the tree tops on Michigan Hill near the north end of the canopy walk.

This is an exciting time for the entire Holden Arboretum family. We saw a changing face of Holden in 2013 and will see even more change in 2014. These significant capital improvements are a prelude to future development at The Holden Arboretum. During the processes, new names have surfaced, lending their support to our efforts, and there are still many wonderful opportunities for naming gifts and tributes. Like a garden, Holden is an ongoing effort and the work will never be done. Like many members of The Holden Arboretum, my family and I have taken advantage of many of the activities offered at Holden such as cross-country skiing, pancake breakfasts, the summer benefit, hiking, summer concerts, photography and

other educational classes, and shopping for special gifts found in the Tree House. Almost 10 months ago, I captured another opportunity at Holden. I temporarily left retirement to serve as interim director of development. The experience has been an exceptional opportunity to come to know many of the people who make the arboretum work on a day-today basis. Keeping the fund-raising ball rolling for the past eight months has been a challenge and a privilege. I am now looking forward to experiencing the new Murch Canopy Walk, strolling along the shores of a revitalized Corning Lake and seeing the new stream and meadow garden in full bloom. Seeing our members and guests exploring Holden makes the work we do here worthwhile.


Spring 2014


Holden Stream Project

Restores Floodplain by Roger Gettig, director of horticulture and conservation

In the United States more than 90 percent of the floodplains have been converted to agriculture, developed or otherwise altered. This has led to the degradation of some of the most valuable ecosystems on earth, harming both water quality and wildlife habitat. Some of those floodplains are on The Holden Arboretum’s property. In 2005, Holden purchased 50 acres along Wisner Road, north of Kirtland-Chardon Road in Chardon Township, because of its existing and potential conservation and educational value. The property includes a mix of natural areas and farm buildings, which support an ongoing horse stable operation. There are more than 2,300 linear feet of the State Scenic East Branch of the Chagrin River running through the property, and the woods on the east and west of the property connect to other Holden forests. The property provides Holden with the best and easiest access to the river for school programs. But some of the historic land uses that have left their mark on the property had to be fixed. There was a 385-foot-long, 10-foot-tall earthen levee that prevented the river from accessing a three-acre floodplain. This, in turn, caused more erosion and flooding downstream. There were also two small streams entering the river from this property that had been severely degraded due to some past land use. We knew when we purchased this property that we would need to restore these areas to reduce flooding and erosion as well as to increase wildlife habitat and water quality. The Chagrin River Watershed Partners (CRWP) and Lake County Soil and Water Conservation District were instrumental in helping Holden establish the scope and goals of the project. These two organizations have been tremendous partners in conservation work with Holden for years.


With the help of CRWP, Holden applied for funding through the Ohio EPA’s 319 matching grant program. CRWP then served as the administrator of the grant funds. The goal of this restoration project was to help this segment of the East Branch of the Chagrin River “in meeting its coldwater habitat (CWH) aquatic life use status by reducing river bank erosion, restoring the river’s access to its historical floodplain and by establishing a densely forested flood plain and riparian corridor within the property.”


Holden had successfully applied for this grant before, receiving funding for the Shadybrook stream restoration project, but this would be the arboretum’s first floodplain restoration project. Holden was awarded $163,450, administered by CRWP, and had to provide $88,878 in-kind service, growing thousands of plants and providing the labor to plant them.

The scope of the project included: • Removal of the 385-foot earthen levee • Restoration of 715 feet of riverbank • Planting three acres of floodplain forest • Restoring a 330’ headwater stream • Restoring and stabilizing a 150’ stream bank • Excavating an area used for manure disposal and connecting it to the floodplain Holden awarded the construction contract to the firm RiverWorks of Stow, Ohio. RiverWorks is a team of restoration biologists, engineers and construction specialists that provides design-build services for stream and wetland restoration. Holden was very pleased with their work, which was completed in the fall of 2013. Chad Knisely, natural areas manager, and his crew have been leading the efforts to replant all the riverbanks, stream banks and f loodplains to stabilized them in face of erosion and also stabilize any areas disturbed by construction. They planted 4,406 plants the fall of 2013 – 3,056 were shrubs including Aronia arbutifolia (black chokeberry), Lindera benzoin (northern spicebush), Cornus sericea (red osier dogwood), Cornus amomum (silky dogwood) and Asimina triloba (pawpaw); 941 trees were planted including Populus deltoides (Eastern cottonwood), Ulmus americana (American elm), and Platanus occidentalis (American sycamore); and 409 herbaceous plantings of Eupatorium maculatum (spotted Joe-pye-weed), Vernonia gigantea (tall ironweed) and Verbesina alternifolia (wingstem). They will plant another 5,600 plants this spring along the stream and river f loodplains and slopes. The plants selected will include cuttings of willow, Eastern cottonwood, Cephalanthus occidentalis (buttonbush) and wetland dogwoods, mostly Cornus amomum mixed with some Cornus sericea. Also included are a selection of sedges propagated at Holden – Carex rosea, Carex radiata, Carex gracillima, Carex stipata and Carex laevigata. A third wave of plantings will take place in the fall, with crews putting in more trees, including Magnolia acuminata (cucumbertree), Nyssa sylvatica (black gum), Liriodendron tulipifera (tulip-poplar), Juglans nigra (black walnut) and Acer nigrum (black maple). Restoration projects that allow flooding in floodplains, not only provide flood protection downstream, but also provide additional ecological benefits. An intact floodplain-river system provides ecological benefits, including habitat for native fish, feeding grounds for migratory birds and primary productivity that supports down-stream food webs.



Spring 2014

One thing that Knisely wants people to understand is that this is not an isolated project. “This restoration project is part of a bigger scheme at Holden, a comprehensive push towards improving our land,” he said. “It fits in with our other restoration projects to improve water quality and wildlife habitat in our natural areas.”


Erica and Calluna

plant facts

Erica carnea Light

Heath and Heather

Full sun to part shade

Soil type

Moist, yet well-drained, acid

by Ethan Johnson, plant records curator

Mature size

0.5-1.5’ tall and spreading with favorable conditions

Best location

USDA Zones (4-5) 6-7


Mail order, garden center or through a landscaper

Calluna vulgaris

Calluna vulgaris

Light Full sun

Soil type Moist, yet well-drained, acid

Mature size

0.5-2.5’ tall and spreading with favorable conditions

Best location

USDA Zones (4-5) 6-7


Mail order or through a landscaper


Erica and Calluna are charming shrubs in the heath family (Ericaceae). They are native to the moors, mountains and woods of Europe, Africa and western Asia. Heaths (Erica) contain more than 700 species, but heathers (calluna) only one. In the 18th century nearly 200 of the 600 plus species of Erica endemic to South Africa were introduced to Britain where nurserymen started their first large scale ornamental plant breeding program. Some 285 named varieties of Cape heath were created but they needed to be grown in a green house. Hardy heaths became popular after World War II. At The Holden Arboretum a number of heaths and heathers are on display as ground covers in the Helen S. Layer Rhododendron Garden, in the Sally L. Gries Entry Garden beds and in the gardens of Lantern Court. The most recent plantings have been in the Eliot and Linda Paine Rhododendron Discovery Garden.


Generally, heaths bloom in the winter and spring while heathers bloom in the summer and fall. During exceptionally warm winters heaths have bloomed during December, January and February at Holden, but usually do not put on a significant show until March and April, with some flowers persisting into May, but rarely into June. Heathers start blooming in July with August being the peak season and some blossoms opening in September and October. Heaths and heathers are insect and wind pollinated, both being nectar sources for honeybees.


The foliage of heaths is small, needle-like and borne in wellspaced whorls on the branchlets. Heathers have tiny needle to scale-like leaves that are closely spaced and borne in four ranks along the branchlets like the four points of a compass. A number of heathers have colorful foliage from fall through winter. In the Paine Rhododendron Discovery Garden Calluna vulgaris ‘Firefly’ is a standout for its colorful foliage. It was awarded the Award of Garden

Merit (AGM) by the Royal Horticultural Society. Other heathers with colorful orange and red foliage planted in 2013 not far from ‘Firefly’ include ‘Blazeaway’, ‘Wickwar Flame’, ‘Winter Chocolate’ and another AGM winner in ‘Robert Chapman’. The most pronounced foliage colors occur in fall, lasting through winter. ‘Silver Knight’ has silvery foliage as do a number of other cultivars. The flowers of Calluna are typically lavender to mauve or white. In the United Kingdom whiteflowered heathers have long been associated with good luck making them a popular flower at weddings.

Erica carnea


The Heather Society of the United Kingdom proclaims, “Everyone can grow heathers!”, but there are some challenges in our climate and soils. Heathers prefer acidic sandy loams that do not dry out. continued on page 16

Louisiana Waterthrush

(Parkesia motacilla) by Rebecca Thompson, Growing Students in Science program coordinator Louisiana waterthrushes are almost exclusively found in mature riparian forests. They are among the earliest long-distance, neotropical migrant warblers to arrive back to Ohio in the spring; typically arriving by early to mid-April. Their riparian habitat consists of steep-sided ravines with fast flowing waters that include rocky beds and many riffles. Louisiana waterthrushes are ground dwellers. They walk slowly, bobbing their body and tails around streams. They are extremely fast feeders, with up to 10 or more feeding maneuvers per minute. Their quick jabbing motion allows them to catch aquatic insects, invertebrates and occasionally small frogs and fish. They also have an interesting habit of foraging under floating debris such as leaves. They have been observed grasping dead leaves in the water and pulling them upward to expose hidden prey. Occasionally, Louisiana waterthrushes may fly upward to catch insects. They also may hover, hawk and glean prey from vegetation too high to be reached from a standing position. Unlike many warblers, male Louisiana waterthrushes do not sing on their wintering grounds. When they arrive on breeding territory males sing vigorously to attract a mate. Once established, the pair chooses a nesting sight in a small hollow or cavity near the root base of upturned trees, or under a fallen log. Nest construction begins about the time of spring leaf-out, with both sexes building the nest. Nests are cup-shape made of leaves,


continued on page 16

bird facts Description Males and females alike. Large warbler with a short tail and long, heavy bill. Upperparts, including the wings and tail, are dark brown. Underparts, white with dark streaking with pinkish buff on the flanks. Throat, white and unmarked; a white eyebrow that widens behind the eye. Relatively long legs and feet pink.

Size 5.5 in; Wingspan: 9.4 in

Range Breeding - Eastern United States, from the southern Great Lakes region to southern New England;

from eastern Texas across the Gulf States to northern Florida. Winters from Central Mexico through Central America into northern South America

Voice Three-four clear, whistled introductory notes that are a slurred upward, followed by a variable complex jumble of short, rapid twitters. Call is a brisk chick or chink.

Best location to view at Holden Pierson Creek and East Branch of the Chagrin River

Spring 2014



Holden announces change in admission, membership rates


By Vicki McDonald, marketing and public relations specialist

The Holden Arboretum is increasing membership and admission rates for the first time in more than 10 years. Since our last increase several years ago, Holden has made significant improvements that increase our value both as a guest experience and as an institution that benefits our region. Those improvements include: • New and improved gardens and guest amenities • School programming • Greater protection of our forests and natural areas • World-class scientific research in ecology and horticulture • Outreach to our region’s professional, government and volunteer “green” communities Holden continues its commitment to promoting a family experience by creating pricing levels that benefit families and young people. With this in mind youth rates will remain discounted and we are extending the youth age limit to 18 and under. We hope that more of our guests will consider becoming members as membership encourages guests to engage more fully with our programs and mission. While we are simplifying our membership levels, the increase is minimal and continues to be a great value. CHRIS LANGER

New Admission Rates Adults (19+) $10


Youth (6 – 18) Child (5 and under)


$4 free

New Membership Rates Individual Member $55

Member Plus $65 Seniors receive $5 discount Pine $125 Azalea $175 Viburnum $300



Spring 2014 by Robin Ott, volunteer coordinator ROBIN OTT

Spring 2014 Featured Opportunities: Volunteer Gardeners Green thumbs, or those who’d like to develop one, are invited to spend one morning a week in one of Holden’s unique gardens. Work alongside Holden horticulturists and fellow volunteers. No experience necessary; hands-on training provided. Shifts are weekday mornings, April through October.

Volunteer Interpretive Person (VIP) Guide Program Future Volunteer, Corbin Ott with Brian Ott I have a three-year-old son, Corbin. Like many three year olds, Corbin is perpetually curious. Much of my day is spent answering his many questions, such as “Why is the moon out during the day?” or “Where does the worm go to the bathroom?” As you can imagine, some of them are easier than others. A couple of months ago, Corbin and I were talking about different jobs, and he asked what I did at work. I told him that I am in charge of managing our volunteer program. I explained that volunteers were people that go out and help others without being paid in money and that I helped people who were interested find ways to volunteer at Holden. He paused and then it came – “Why do they do that?” Corbin’s question was a good one – why should someone come and volunteer at Holden? Whether we are employed or retired, there are hundreds of ways to fill our days and responsibilities we must attend to. How does one fit one more thing in? I believe that making some time to volunteer at Holden can benefit your mind, body and soul. Volunteers here learn new things; whether it’s the proper name of a plant or enhanced speaking skills, the opportunity to expand your knowledge and try new adventures are many. Many of our positions include some level of physical activity – so you can come spend some time with us instead of going to the gym. Volunteering at Holden also fulfills a spiritual need to be part of a community. Holden volunteers all share a love of nature. Being on the grounds regularly provides peace and a beautiful retreat from the rest of life. Corbin may not be able to understand the reasons above at this age, but I was able to give him an answer he could, “Volunteering at Holden is fun! We have parties, get to play in the dirt and it’s a good way to meet new friends.” He thought about it and then said “I want to volunteer!” I explained that he’d have to be a little older before he can volunteer, but we could still go and play at Holden until he could.

VIP guides share with guests Holden’s history, mission and horticulture highlights through a one-hour tram or one-and-a halfhour walking tour of the gardens and grounds. Training includes attending four training sessions and shadowing of veteran guides. Guides each bring their unique perspectives and experience. No previous guiding experience necessary, but strong communication skills and an interest in talking to and sharing information with others are important. Physical demands vary by tour, but mobility and ability to work outside is required. Note: Must be able to attend a minimum of three out of the four classes and make up missed class through additional shadowing.

School Guide Program School guides lead children through an activity-based educational exploration of Holden’s plant and wildlife communities. Guides facilitate activities based on planned science curriculum. Teaching experience helpful, but not required. Anyone who enjoys discovering new things with children, is a good communicator and physically capable of being outside and walking for up to two hours are welcome. Weekday availability a must. A one-day training session will be scheduled in early spring; new volunteers also train by shadowing. To learn more about these, and other volunteer opportunities, visit or contact the Holden volunteer office at 440.602.8003.

2014 Summer Junior Volunteer Applications Due March 14 Know an outstanding high school student (age 14+) who loves nature, trying new things and wants to make a difference? The Holden Arboretum Summer Junior Volunteer program provides students like these a unique summer volunteer experience. Junior Volunteers will serve two or three half-day shifts a week between June 16 and Aug. 1, 2014 in an assignment that matches their interests, and get to take part in weekly outings to learn more about Holden and have fun. Last year, students worked with staff in horticulture, conservation, the nursery, education, marketing and administration. Application deadline is March 14. Application and details are available online at or can be requested from the volunteer office at 440.602.8003. Program lasts six weeks, June 16 - Aug. 1.

Spring 2014

Why not get involved today? Contact the Holden volunteer office at 440.602.8003 or email rott@ for application and more information.

2014 Training Series: Saturdays, April 19, May 10, June 7 and Sept. 27, 9am - 4pm


plant this not that

by Natalie Gertz-Young, education/information coordinator, Lake County Soil and Water Conservation District

Thousands of plants have been introduced to the United States from other parts of the world. Some have come here accidentally in seed stock, while others were brought here intentionally for horticultural use. A small number of these introduced plants have gotten a little too comfortable in their new environment. Because they have no native predators and produce a lot of fruit and seed that are efficiently dispersed, they are invading natural areas. The aggressiveness of these invasive plants affects natural areas and wildlife by decreasing biodiversity, competing with native and rare plants and eliminating wildlife habitat and food sources. Plant This, Not That features a list of native alternatives to a commonly used landscape plant that has become invasive. The alternatives were chosen because their characteristics – form, flowers, fruit or fall color – are similar to that of the invasive and fulfill the same landscaping need. Plants that are native to Ohio are recommended when possible as native species are generally well-adapted to local climates and provide additional resources for wildlife. However, there are many non-native plants on the market that are also non-invasive and possess great ornamental value.

The Invasive

Phalaris arundinacea (Reed Canary Grass) “. . . my observation with reed canary grass is that it is wise not to plant it if one wishes ever to get rid of it.” While that might seem like advice from a modern conservationist, it is actually a quote from a text written in 1940 by Indiana botanist C. C. Deam. Deam’s observation has proven true as Phalaris arundinacea has become a subtle and pernicious invader of Ohio’s wetlands and disturbed uplands. While many invasive plants are introduced by accident, the introduction of P. arundinacea was far from unintended. P. arundinacea was introduced to Northeast Ohio in two different ways. The first started as early as 1850 when varieties were brought over from Europe for use as forage. In 1929, the USDA recommended planting P. arundinacea and praised its tolerance for wetland soils and cold winters, rapid spread and early maturity. The second way in which Phalaris arundinacea var. picta P. arundinacea is introduced John M. Randall, The Nature Conservancy is as an ornamental grass. P. arundinacea ‘Picta’ and P. arundinacea var. picta ‘Feesey’ are varieties with variegated leaves. They are commonly called “gardener’s garters” or ribbongrass. They are garden favorites because of their striking leaves, rapid spread and tolerance for wet and saturated soils.


This cool-season perennial grass crowds out native plant species by spreading two ways, rhizomes and seeds. The seeds, which ripen in midJune, are dispersed by wind and water. But P. arundinacea most aggressively spreads by rhizomes. In fact, the plant can sprout from even the smallest remaining section of root. P. arundinacea is also able to grow in disturbed soil, waterlogged soil and in high nutrient environments. This means that it thrives in areas close to lawns, golf courses and farm runoff. This plant is not only harmful to native plant populations, but it is also detrimental to wildlife as it is a poor provider of food and habitat for animals such as song birds and young mammals.


Phalaris arundinacea var. picta Missouri Botanical Garden

While this species can be managed with a combination of mowing, wetland-approved herbicide and controlled burns, its spread is hastened by continued planting by farmers and gardeners.

The Alternatives Carex morrowii ‘Ice Dance’ This sedge is a dense-spreader, has attractive 12-inch-long variegated leaves and likes its feet wet. All of these qualities make this Japanese native a great choice for the home garden. While it is not native to the Northeast Ohio it is not known to spread into wild areas and therefore does not pose a threat to native plant and animal populations. ‘Ice Dance’ does prefer part to full shade so it is best planted in a woodland garden or shaded border.

Carex morrowii ‘Ice Dance’

Ed Hedborn, Missouri Botanical Garden

Chasmanthium latifolium ‘River Mist’ Variegated Northern Sea Oats This variegated variety of Chasmanthium latifolium, commonly called Northern or Inland Sea Oats, is a relative newcomer to gardens and nurseries. ‘River Mist’ tolerates a variety of soil types and light conditions, and doesn’t mind extended periods of saturated soils. In fact, it thrives in moist soils with dappled shade. Its growth habit is reminiscent of bamboo and grows to about 2-3 feet in height. ‘River Mist’ has the added benefit of adding winter interest as it retains its oat-like seed heads into winter, thus providing food for wildlife.

Chasmanthium latifolium ‘River Mist’ Ed Hedborn, Missouri Botanical Garden

Panicum virgatum ‘Ruby Ribbons’ Red Switch Grass If striking color and contrast is what your garden is missing Panicum virgatum ‘Ruby Ribbons’ may fill the void. While its leaves are not variegated, they provide superb color with their wine-red tipped leaves and flower panicles, the latter of which persist into winter. With foliage that can grow to about four feet in height, this well-mannered grass is tolerant of wet and dry soils and grows best in full sun to part shade. Examples of ‘Ruby Ribbons’ can be found in Holden’s Display Garden. Spring 2014

Panicum virgatum ‘Cheyenne Sky’ Walters


Horticulture Science Center marks

20th Anniversary by Cait Anastis, editor


While visitors to The Holden Arboretum rarely see the inside of its Horticulture Science Center (HSC), the work being done there is earning national recognition as Holden scientists explore the importance of biological diversity to the function and management of forests, the mechanisms that help plants and ecosystems tolerate environmental change, and how plants and soils respond to natural and human-induced stress. This April will mark the 20th anniversary of the HSC’s opening, originally built to provide workspace for Holden’s then-fledgling research program. From the outside, the building looks much as it did when it opened in 1994. Inside, laboratories have been upgraded to accommodate the expanding number of people who now work there. Holden has four full-time scientists, two research specialists and a research assistant. It also regularly hosts graduate students and undergraduate interns working on projects with the Holden staff. Relationships with other organizations, including the U.S. Forestry Service and several area universities, including Ohio State, Case Western Reserve and Kent State, provide opportunities for collaborations and offers researchers at those institutions access to Holden’s collections and natural areas for their work. (Editor’s note: Read more about Holden’s collaboration with the U.S. Forestry Service on page 15 of this issue.) Research specialist Charlotte Hewins started working for Holden’s research department as a summer intern when the program was still based in laboratory space at Lake Erie College. She joined Holden’s full-time staff in 1993, while the building was under construction. Because the HSC only is open to the public on rare occasions, she said, many people may be unaware of the scope of the work that takes place there.


Horticultural research, the original focus of Holden’s science program, is still a part of Holden’s research department. Steve Krebs, the director of Holden’s David G. Leach Research Station, is creating new rhododendron hybrids with improved disease resistance, recently releasing two new plants into the marketplace – ‘Solar Flair’ and ‘Summer Herald’. He also is testing new hybrids for increased heat tolerance. But the scope of the research program has expanded into other areas.

“I think people would be surprised at the level of technology in this building,” Hewins said. “When people think of an arboretum they don’t necessarily think of the seriousness of the science taking place here.” JOHANNA LYMAN




But a focus on serious science was the driving force behind the HSC’s construction in 1994 and remains its purpose today. At the time that it opened, the Horticultural Science Center was hailed as an excellent home for the research program, with Eliot Paine, then director of Holden, calling it the start of “a new era of horticultural propagation and research.”

“A lot of the work that we’re doing now focuses on soil ecology and soil chemistry,” said David Burke, chairman of the department. “We’re using DNA techniques to explore the function of different organisms in the forest.” Holden’s research interests have expanded to include projects exploring the function of forest ecosystems with the hope of finding better methods of managing forests in humanimpacted areas, which is especially important as forests are threatened by invasive organisms, climate change and other stresses. The goal is to have a small, but world-class research program that has maximum positive impact for society, said Clem Hamilton, Holden’s president and CEO. Conducting outstanding research in ecology and horticulture has an impact on two of Holden’s strategic themes – conserving native forests and growing trees and communities – making research an important area for future growth. The goal, Hamilton said, is to continue to grow a significant program that is respected for cutting-edge science that fills in important gaps in our knowledge and leads to improved applications in the field, whether it is home gardeners planting in their gardens or improvements in managing forests sustainably for higher ecological value. “The more scientists we can have on staff, the better,” he said. “We have a dynamite core of scientists, and we have identified other areas of research that would complement what we have right now and expand our service.” continued on page 18

Holden and the U.S. Forest Service

Working Together to Fight Beech Bark Disease by Vicki McDonald, marketing and public relations specialist The Holden Arboretum has been collaborating with the U.S. Forest Service for nearly a decade on the fight against beech bark disease, an invasive pest/pathogen disease complex attacking Fagus grandifolia (American beech). Beech bark disease, known to cause death and defects in beech trees in North America and Europe, is the result of the nonnative, soft-bodied scale insect Cryptococcus fagisuga, which attacks the bark of the tree creating small fissures and providing an entry point for invasive fungi. Two types of fungi, Neonectria faginata and Neonectria ditissima are known to infect American beech and cause cankers that weaken and ultimately kill the tree. According to the Forest Service, initial mortality can be 50 percent or higher. The trees that are left are often deformed and weakened, and may eventually succumb to beech bark disease or

Michigan Department of Natural Resources. The long-term goals were to preserve resistant trees and establish seed orchards comprised of these offspring. In 2003, Holden was identified as a partner for this work since, at the time, the disease had not been found in Ohio outside of Holden. All Forest Service scale-resistance screening was carried out at Holden in partnership with the research department. Koch leads these efforts and has conducted experiments exposing both susceptible and resistant trees to the scale insect. The research showed that some trees are in fact resistant to the insect and that resistance is a genetically heritable trait.


In 2006, 400 American beech saplings were planted at Holden’s Lower Baldwin research plot where long-term disease resistance research and breeding continues. “We are working with David (Burke) to protect resistant trees, remove susceptible ones and increase genetic diversity by eventually adding additional resistant genotypes” said Koch. “Holden is a great partner; they are vested, they’ve dedicated their own resources, have let us borrow interns and they provide all of the plant maintenance.”


The disease has now been identified in five counties in the state of Ohio, and The Holden Arboretum continues to be an important partner in developing a solution to the large scale, detrimental affect of beech bark disease. Koch said. “Most of what we’ve been able to accomplish in the last 10 years we would not have been able to do without Holden’s help.” other diseases that affect forest trees. The good news is that there are beech trees resistant to the disease or at least the scale insect that infest the trees. Forest Service research CHRIS MALUMPHY, THE FOOD AND ENVIRONMENT indicates that these “clear” trees RESEARCH AGENCY, BUGWOOD.ORG are rare and sometimes found in clusters. “These clusters have been CLOCKWISE FROM LEFT: shown to be clonal or closely related by molecular markers,” BEECH BARK DISEASE, said Jennifer Koch, PhD, a research scientist with the FUNGUS FRUITING Forest Service who conducts some of her disease resistance BODIES, research on beech bark disease at The Holden Arboretum. BEECH SCALE

To find out more about Koch’s research visit invasive_species/bbd_resistant_beech.

Spring 2014

In 2002, the U.S. Forest Service initiated a disease resistance breeding program targeting beech bark disease with the

In October 2013, Koch and her colleague, David Carey, a biological technician with the Forest Service, were at Holden recording a video that will demonstrate the process for screening beech trees for resistance to the scale insect. The video will be published by the Journal of Visualized Experiments on, a peer reviewed scientific video journal.


Erica and Calluna (continued from page 8) A blanket of snow can protect them from low temperatures and winter sun. However, in harsh winters like 1995-96 when snow cover was not consistent, there can be significant mortality and severe injury to all heaths and heathers in our climate. While smaller plantings can be protected from winter wind and sun with evergreen boughs, this may not be practical for many gardeners. Heather needs to be pruned annually in order to remain showy. In our climate pruning in early spring before new growth starts is best and fall or winter pruning is not recommended. Shearing off old spent flower heads along with taller stems that did not flower makes for fuller and more ornamental plants. However, the dwarf varieties or “bun” types do just fine without any pruning. Spring heath (Erica carnea) is a native of the mountains of central and southern Europe, most famously the Swiss Alps. This is the most common heath in our gardens. Erica carnea ‘Springwood White’ is well established in Heath Vale of the Layer Rhododendron Garden. ‘Springwood Pink’ can be found

on the west side of the Layer Garden, but the area has become so shady that it is rather sparse. New plantings in the Paine Rhododendron Discovery Garden include ‘Pink Spangles’, ‘Rosalie’, ‘Tanja’, which is also pink-flowered, and the whiteflowered ‘Schneekuppe’. Erica carnea should be pruned in late April or early May for the first few years after planting. Thereafter, they can be pruned every other year to achieve fuller plants and longer flower spikes. Mature Erica carnea can spread 4’ or more. Overgrown plants can be lifted by the ends and pruned from beneath to keep them in bounds. Good companion plants for heaths and heathers include cranberry, dwarf conifers, lavender, thyme, red-hot pokers (Kniphofia), black mondo grass (Ophiopogon planiscapus ‘Nigrescens’), or even small daphnes such as Daphne ‘Kilmeston’ or ‘Lawrence Crocker’ to add fragrance to the bed.

Louisiana Waterthrush (continued from page 8) bark strips, twigs and lined with fine plant stems, rootlets, hair and moss. Females lay four to six white to creamy-white eggs with reddish brown speckles, spots or blotches that are usually concentrated at the large end, but sometimes scattered evenly over the entire egg. Eggs are incubated by females for 14-16 days. Males do not feed females, but will accompany females when foraging. Young are fed by both parents and leave the nest 10 days after hatching. Fledglings can fly six days after leaving the nest and begin feeding on their own at seven days. Adults only have one brood and depart breeding territories by July.

Louisiana waterthrushes are of high conservation importance, because of their dependence on healthy forest stream ecosystems both on its breeding and wintering grounds. Local populations are very sensitive to changes in habitat quality and quantity. Extensive deforestation on the wintering grounds is likely a serious problem in certain areas. The Louisiana waterthrush is ranked as a species in need of monitoring in the southern United States by the U.S. Fish and Wildlife Service, and as a species of concern by Partners in Flight in the south.

Alicia Soss has been named associate director of development and director of planned giving, the latest role in her nearly 30-year career with Holden’s development department. Soss will be responsible for designing activities that expand the giving opportunities at the various donor member levels, and for creating and directing Holden’s planned giving/estate planning program, as well as performing her current responsibilities.


Alicia Soss Leaves

Associate Director of Development and Director of Planned Giving


“We are confident that Alicia will continue to enhance relationships with all of our constituents resulting in increased giving to Holden,” said Clem Hamilton, president and CEO, as he made the announcement in December. “The work that she has accomplished with memorials and tributes will flow seamlessly into the establishment of a planned giving program, providing giving opportunities for donors in their estate plans. This is a welcome evolution in our development program, as planned giving is a key reflection of our donors’ growing dedication to Holden’s future.” Soss started with Holden in 1984 as a development assistant before being promoted to development coordinator and most recently to the position of associate development officer. She is celebrating her 30th anniversary with Holden in 2014. “To many of our donors, Alicia is a key and trusted face of Holden,” Hamilton said. “Her latest promotion is a natural progression in her ever increasing role in our fundraising.” A resident of Chardon, Ohio, she and her husband have two daughters.





When should I plan a visit to the arboretum to see (fill in the blank)?


by Greg Wright, nursery supervisor

This is a common question that we get asked, and it can be slightly difficult to answer. It depends on what Mother Nature provides in regards to warm temperatures in the spring, which can affect the flowering of plants by sometimes weeks. In some years the weather has been so unpredictable that the bloom period ends up being shortened into just a few weeks with combinations of flowers that don’t usually

occur together blooming at once. Because of this, it becomes difficult to predict when something will be in bloom or when things are going to be in peak. Though there are many plants to be appreciated at The Holden Arboretum, three groups of plants most visitors enjoy are the lilacs, rhododendrons and spring wildflowers. The chart below will provide guidelines as to when to expect to find these plants in peak bloom.




Early to Mid Lilacs Mid to Late Small leafed rhododendrons Mid to Late Large leafed rhododendrons Late


Evergreen azaleas All


Deciduous azaleas Late

Early to Mid

To find out what is currently in bloom at Holden, visitors can call 440.946.4400 and select the appropriate option on the dialing tree or visit the Holden website at to see a monthly update of the plants we anticipate will be in bloom. Visit anytime to enjoy the gardens and trails because there is always something new to enjoy.

Spring 2014



Research News and Highlights Holden’s Recipe for Southern Rhododendrons A rhododendron breeding project to create disease resistant and heat tolerant hybrids has progressed to the advanced trialing stage. More than 160 plants from field populations maintained at the David G. Leach Research Station were selected based on their ornamental and vegetative attributes, propagated by rooting stem cuttings, and then shipped to southern Louisiana in the fall of 2013 for a replicated field test in USDA hardiness zone 8b or Gulf South conditions. A full season of high summer temperatures, higher than average rainfall and strong disease pressure from the root rot soil pathogen has resulted in about 30 percent casualties overall, but many of the survivors are doing well. Results from at least one more season will be needed prior to making selections for commercial release. The southern trials are being done in partnership with Plant Development Services Inc. in Loxley, Ala., which would put rhododendron introductions into their

well-known Southern Living Plant Collections brand. A successful and novel outcome of these efforts would be the development of rhododendron hybrids capable of cultivation over a wide range of climates (hardiness zones 5 - 8) and better performance in the home landscape due to enhanced resistance to root rot disease. This work was recently presented by Steve Krebs at the 2013 International Plant Propagators Society Southern Region conference in Athens, Ga., in a talk titled What’s Cookin’ with Southern Rhododendrons. Learn more about the rhododendron breeding program in the spring 2011 issue of Leaves, online at

Horticulture Science Center marks 20th Anniversary (continued from page 14) While their work may not be noticeable to the average visitor, Holden’s scientists have earned two highly competitive federal grants to fund research projects and have forged partnerships with researchers at federal and state institutions. In 2009, Holden scientists earned a $519,000 grant from the National Science Foundation (NSF), which allowed them to examine the important role soil organisms play in acquiring limiting nutrients from the soil for forest trees. The project was the result of a partnership between Holden and Ohio University in Athens, Ohio. A second collaboration, which partnered Holden with Kent State University, earned a NSF Research Undergraduate Education (REU) Site Grant in 2013. The project funded by the $345,000 grant is designed to train the next generation of scientists. The training program brought students from around the country to Northeast Ohio to learn how to conduct research from experts in the field at Kent State and Holden. Receiving the two grants from the NSF shows the caliber of the program Holden is building, Burke said.


“The NSF is one of the world’s premier research-funding organizations,” he said. “Funding from the NSF is very difficult to get – funding rates are very low, with anywhere from 3 to 5 percent of proposals receiving funding. An NSF grant is indicative of a nationally recognized research program.”


Holden’s science program gives the arboretum some distinction and places it in the upper echelons of arboreta, Burke said, and extends Holden’s impact far beyond our own region.


“There are probably a small number of public gardens and arboreta that have serious science programs, that are publishing in international scientific journals and are competing for federal grant dollars,” he said. While expanding the staff is one method for growing the program being explored, Holden is also looking at other methods including strengthening its collaborative relationships with universities and government organizations, continuing to increase Holden’s involvement with undergraduate training and expanding the use of the collections and natural areas for research by Holden scientists and its outside partners. A key component to this expansion will be attracting external funding to support growth in the sciences. “We are progressing now on all those fronts, and intend to reach the next level,” Hamilton said. “We have laid our foundation and are off to a good start, which I am sure the early supporters of Holden’s increase dedication to original research would find gratifying.”

Simplify and Save Resources


Help Holden simplify by sharing your email address with us. We would like to communicate with you via email whenever possible. We have just recently begun sending electronic membership renewal notices to our members. If you renew by the date indicated in the notice it really helps us to reduce the need to mail out renewal notices. This electronic process is the fastest, simplest way to renew and together we can save resources and reduce our environmental impact. By providing us your email you will also receive things like Treemail, Holden’s monthly newsletter, providing updates on special events, Holden happenings and opportunities for visitors. Help us simplify today and send your email address to Dawn Gettig at

Save The Date: Saturday, July 12, 2014 Holden’s annual summer benefit

New dates, time announced for Summer Concert Series. We’re getting an early start on our 2014 Summer Garden Concerts this year, kicking off the series on June 17. Concerts will be held every Tuesday evening through Aug. 5. We’re also changing the time, with performances running from 7–8:30pm. We’re currently looking for talented local bands to take part in the series. Visit for more information on the call for bands and check back in April for the line up of performances.

Spring 2014



periodicals ®

9500 Sperry Road Kirtland, Ohio 44094 440.946.4400

Please notify Holden of change of address.


Malus ‘Silver Moon’ in the Conifer Collection

postage paid Mentor, Ohio

Leaves Magazine Spring 2014  

Leaves Magazine is the quarterly publication of The Holden Arboretum, focused on horticulture, conservation, education and ecological resear...

Leaves Magazine Spring 2014  

Leaves Magazine is the quarterly publication of The Holden Arboretum, focused on horticulture, conservation, education and ecological resear...