A PUBLICATION OF the holden arboretum
Spring
2010
Spring 2010
1
leaves
Spring 2010
Cait Anastis, Editor
[email protected]
Jackie Klisuric, Graphic Design
administration
Clement W. Hamilton,
President and CEO
Jim Ansberry,
Director of Finance
Jack Blackwell,
Director of Human Resources and Safety
David A. Desimone,
Director of Guest Relations and Communications
Pamela M. Eichenauer,
Director of Development
Roger Gettig,
Director of Horticulture and Conservation
Paul C. Spector,
Director of Education
from the president
Mary A. Topa,
Director of Research
board of directors
Joseph J. Mahovlic, Chairman
Paul R. Abbey, Vice Chairman
Jonathan E. Dick, Vice Chairman
Robert R. Galloway, Vice Chairman
Sarah L. Gries, Vice Chairman
Leslie W. Jacobs, Vice Chairman
C. W. Eliot Paine, Vice Chairman
Stephen J. Knerly, Secretary
Jackie klisuric
contents
features
Trees & Communities
Upper Baldwin
Loving Life To The Fullest
Holden Grows Rhododendrons
Sharing a Holden Tradition
6
7 Bird Bio
10 Volunteering
11 Ask Greg
17 Research Updates
Plant Profile
Liriodendron tulipifera
Wood Duck
directors emeriti
Constance N. Abbey
Ralph W. Abelt
Miriam N. Gale
Henry R. Hatch
T. Dixon Long
William J. O’Neill Jr.
Penelope Theis
Alton W. Whitehouse
honorary directors
Anne Clapp
Mary Groves
Alison C. Jones
Spring Volunteer Opportunities
Plant Q & A
Plant Introductions
Enjoy the Beauty of Holden
Volume 8, Number 2
©The Holden Arboretum
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
Often people ask me, “What makes a great arboretum? Is there a rating system? How
does Holden stack up?” First, thank goodness, there is no formal rating system. But
here is a set of attributes I look for in an outstanding arboretum; and, like any museum,
we start with collections and displays. A great arboretum (1) grows a comprehensive
collection of exemplary trees, effectively arranged to tell stories about their diversity,
horticulture, ecology, evolution and human uses; (2) provides visitors an experience that is
restorative, transformative and just plain fun; (3) adds significantly to the world’s knowledge
about trees and their environments; (4) contributes to the conservation of trees and forests; and
(5) in short, improves the world.
The elite arboreta – Morton Arboretum in Illinois, the U.S. National Arboretum in Washington,
D.C., and the “mother ship” that started it all, Harvard’s Arnold Arboretum, come first to mind
– feature all those attributes, in spades. And there are many others that stand out, such as
Minnesota Landscape Arboretum; North Carolina State Arboretum; my old bailiwick in Seattle,
Washington Park Arboretum; and, more locally, the Dawes and Secrest arboreta, well worth
multiple visits.
As to Holden’s place in the pantheon, the title of Jim Collins’s classic book on organizational
transformation, From Good to Great, is à propos. The pages of our Leaves magazines, over
time, document our progress and our impact, of which I hope you are as proud as our staff
and board, and testify to the inspiring work by everyone in our Holden community. Look for
new icons for each strategic theme, plus the general “Holden Experience,” which emphasize
the increased focus and integration of our research, education, tree collections, natural areas
management and visitor programs.
These are exciting times. Thank you for being such an important partner in our great endeavor.
Periodicals postage paid at Mentor, Ohio
Leaves
Leaves
2
Richard S. Kanzleiter
Michael C. Marino
Cynthia Moore Hardy
Jeffrey K. Orloff
Thomas R. Ruhe
K.K. Sullivan
Michael T. Victor
Ann T. Whitney
“The Holden Arboretum cultivates beautiful and healthy trees, forests and
communities.” There it is, what we do, in a nutshell. Is it a motto? A slogan? A mission
statement? Maybe it should be considered a way of life. Whatever we call it, it’s a good
way to start any conversation about Holden and its significance to the world. And it’s
short enough to Twitter (whatever that is)! Perhaps those 11 words encompass our
primary strategic directions – growing trees and communities, conserving native forests
and engaging children with nature – and point the way toward our becoming one of
North America’s elite arboreta and public gardens.
Cover photo by Jackie Klisuric
Postmaster:
Please send address changes to
Leaves: The Holden Arboretum,
9500 Sperry Road,
Kirtland, Ohio 44094-5172
Clement W. Hamilton, PhD
President and CEO
Spring 2010
4
5 Clean Up
8 Partnerships
a
Garden Classic
12 Modernizing
14 Pancake Breakfast
16 Spring Splendor
The Holden Arboretum:
departments
Barbara Brown
Jeanette Grasselli Brown
Christopher A. Cullis
Simin Gharib-Naraghipour
Jane Grebenc
Stephen G. Hartle
Peter Hellman
Arlene M. Holden
Jackie klisuric
3
grow
i
s
itie
un
Strategic Initiative:
Growing Trees & Communities
s & com
m
tree
g
n
Holden’s acreage has grown to more than
3,600 acres, with an additional 1,400 acres in
conservation easements. But as we see it, our
responsibility doesn’t end there. We want to
inspire people in Northeast Ohio to cultivate
and create sustainable home gardens; volunteer
on community tree boards, park commissions,
by Cait Anastis, editor
Tucked away behind The Holden Arboretum’s
specimen tree collection on Baldwin Road is a
path that winds down through the woods and
across Shadybrook stream to Upper Baldwin.
Editor’s note: This is the second in a series exploring The Holden Arboretum’s
new strategic directions, which were approved by the Board of Directors in 2009.
When we selected growing trees and communities
as one of Holden’s strategic directions, we
were inspired by a vision: Interconnected
networks of trees and wooded environments
– from street trees to home gardens to green
spaces – that sustain the ecological health of
the communities where we live and work.
Spring Cleaning at Upper Baldwin
We understand that one need not be an expert
in order to share and appreciate our vision. With
new spaces for entertainment and enjoyment,
such as an event meadow for special events
and structures to accommodate larger groups
for receptions, lectures and dinners, Holden
will be a destination for beauty — and inspire
popular support for improving the health of
trees, forests and communities of the region.
“The goal was to open it up enough so that
mowing could take care of the vegetation control,”
he said. “One of the big goals was to eliminate
shrubs for maintenance purposes. Shrubs require
a higher maintenance level than do trees. If they
don’t get it they deteriorate.”
Once Tubesing had determined
which plants should stay
and which plants would be
removed, Ethan Johnson, Holden
plant records curator, was
responsible for removing them
from the arboretum records.
One step toward meeting this goal is new work
in the area of plant introduction. Holden’s plan
calls for the introduction of woody plants with
novel stress adaptations and aesthetic attributes
for public benefit and enjoyment in gardens,
Plants cultivated in Holden’s
collections are accessioned. Each
has a unique number indicating
the year Holden acquired
the plant and its source. The
record is what makes Holden
a living, outdoor museum.
brian parsons
During the summer of 2009, it received the
equivalent of a spring cleaning as members
of the horticulture crew removed plants
to make the area easier to maintain.
“The idea is that we know how we
received it, when we received it, what it is, where
it was planted, how it’s doing, when it blooms and
map it, label it and get it in the catalogue,” Johnson
said. “We periodically check their condition, size
and reproductive state and include that information
in our database, providing Holden with an
ongoing record of the plants and their growth.”
“As a tree museum, evaluating and learning from
plants on the grounds is a key part of work at
Holden,” said Roger Gettig, director of Horticulture
and Conservation. “However, at Upper Baldwin, a
While the project removed
number of plants
remained long after
their purpose had
Plants cultivated in Holden’s collections are accessioned.
been fulfilled.
Each has a unique number indicating the year Holden
acquired the plant and its source. The record is
what makes Holden a living, outdoor museum.
Jackie klisuric
4
We can accomplish this through gardens and
living displays that demonstrate how to realize the
benefits provided by plants across a continuum
of landscapes – whether efforts yield a green
roof on a new building or a water garden in a
suburban yard – we want to foster the ideas and
provide the intellectual resources needed. Display
gardens and new woody plant collections will
be expanded to include home demonstration
gardens, a sensory garden, and a children’s
woodland exploration area, just to name a few.
community landscapes and natural areas. In
this issue of Leaves you can read more about
the work being done at Holden’s David G. Leach
Research Station, where new rhododendrons are
ready to be introduced in the marketplace.
Holden also will be working to introduce pest and
disease resistant selections of native woody plants
for use in community landscapes and the region’s
native forests. On page 19, Mary Topa, director
of research, discusses the benefit of introducing
Holden plants for use in area landscapes.
continued on page 11
For decades, Upper Baldwin has given horticulturists
a place to plant trees and shrubs for evaluation
of how well they will grow in the region’s climate
and soil. Some of the specimens, combined with
the remote nature of the field, made maintenance
more difficult and time consuming for the staff.
Clearing out some of these test plants started
with Charles Tubesing, Holden’s plant collections
curator, taking a look at what was growing at
Upper Baldwin to determine what should be left
in place. Many of the plants that were removed
could be found elsewhere on the grounds.
The dawn redwoods are significant because they
represent a broad range of genetic diversity.
The original dawn redwood seedlings planted
in the United States were all collected from a
single tree in China. A later expedition collected
seeds from trees throughout their natural range,
Johnson said, for a greater sampling of genetic
diversity. The trees at Upper Baldwin are from
the later collection and are one of the largest
groupings of dawn redwoods at Holden.
Also left in place was a large Larix decidua var.
polonica (Polish larch), one of the most beautiful
examples of its species that can be found at Holden.
continued on page 15
Spring 2010
Leaves
and land steward groups; successfully
manage their own small forest lots; and raise
their children to value trees and nature.
“We’re essentially
going over
inventory
and seeing
what we use,” Gettig said. “This is Holden’s
attic where we’ve been storing stuff, but never
evaluating whether we need it or not.”
a number of plants,
there are still plants of
interest growing there,
including a cluster of
young white pine trees
grown from seeds
collected on Little
Mountain and a grove
of dawn redwoods.
5
Liriodendron tulipifera (tuliptree)
Wood Duck (Aix sponsa)
by Ethan Johnson, plant records curator
by Rebecca Thompson, Growing Students and Science program coordinator
I love seeing the new leaves of Liriodendron
as they unfurl in late April, the flowers as
they bloom in late May and June, and
the golden-yellow leaves as they fall
in November. Groves of tuliptrees
are magical places to be.
Today wood ducks are one of the most common
breeding waterfowl species in the United States.
Words cannot describe the vivid markings of the
drakes or male wood ducks. Their lines and colors
are so striking that during breeding seasons they
are considered by many to be the most beautiful
of all waterfowl. Even hens, females, with their
teardrop eye rings and iridescent plumage are
quite stunning when compared to other ducks.
In the natural areas of
The Holden Arboretum,
Liriodendron tulipifera is the
third most common species
next to sugar maple and
American beech. It is found
in all our forest types and
is especially prevalent in
old fields abandoned last
century. Their trunks tend to
be straight. One old tree in Bole
Woods measures 4’ in diameter at
breast height (DBH) and although
a bit stag-headed, is 135’ tall.
kiwinz
plant facts
Light
Full sun
Soil type
Constantly moist, well to
moderately well-drained,
slightly acid
Mature size
80’-100’ or more, usually
with a lesser spread
Best location
USDA Zones 4-9
Source
Local nurseries
In the gardens our largest specimen
is at Lantern Court near the east terrace
just off the circle. It was planted in the early
1930s and now measures 98’ tall, 60’ wide and
32” DBH. In the lawn just north of the Myrtle S. Holden
Wildflower Garden’s woodland section is a specimen that has
low branches for easier viewing. It was a 5’-6’ tall native sapling
planted in 1962 that lost its leader, developed a double trunk
at 15’ and now measures 72’ x 44’, 27” DBH. Birds such as
cardinals frequently perch high in its branches to sing and
many others including warblers may be seen flitting about
looking for insects in its crown. Purple finches eat the seed
that ripens in late October. The seed is shed from November
through the winter months, primarily on sunny dry days.
djpmapleferryman
bird facts
Description
Both sexes have crested head. Male:
Incredibly colorful throughout; white
throat, green head, red eye. Female:
gray with darker crown; large white
teardrop eye ring
One distinctive cultivar of tuliptree is a narrowly upright selection
named ‘Fastigiatum’ that was planted July 12, 1995 in the
Display Garden as a grafted 10’ balled and burlapped specimen.
It now measures 34’ x 19’, 7.6” DBH. As with the species, the
bloom provides nectar and pollen for beetles, honeybees and
numerous native insects but they can easily be overlooked from
a distance, and are of particular interest only when borne low
enough for close inspection. Flowering usually lasts between
three to five weeks with the record being from May 23 through
June 30 in 2003. A cultivar with yellow marginally variegated
leaves named ‘Aureomarginatum’ was planted in the Holly
Female often calls “oo-eek, oo-eek”
as it leaves an area
Size
Blueberry Pond, Buttonbush Bog,
Hour Glass Pond and Corning Lake.
Female wood ducks usually lay eight-10 white or
off-white eggs in a bare, cavity. She alone sits on
the eggs for 28-32 days; taking only a short time
in morning and evening to feed. Within a day after
all the young have hatched, in response to the
female’s call, the hatchlings use their clawed feet
and bills to climb up to the entrance of the cavity
then drop down to the ground to make their way
to the water. They can drop from 75 ft high or
more from a tree without injury. Young are tended
exclusively for the next 56-70 days by the female.
Wood ducks dramatically declined in late 19th century.
Overhunting and logging of woodland swamps
caused the duck to be on the verge of extinction.
The valley of the East Branch of the Chagrin River is dominated by Tuliptrees. After the maple, ash,
elm, and other trees lose their fall foliage, the yellow crowns of the Tuliptrees, Liriodendron tulipifera
appear in sharp contrast to the remaining oak and conifers which blanket the slopes of the valley.
alex lomas
Best location to view at
Holden
Luckily, current
populations have
stabilized or
increasing due
to the efforts of
land preservation
and hunting
regulations.
However wood
ducks are still
considered a
popular game
bird, and are
second only
© 2007 dino quinzari
to the Mallard
in numbers shot each year in the United States.
What you can do to help! Consider supporting land
preservation organizations and help create local
wood duck breeding habitats for future generations.
Landowners with ponds can install wood duck boxes.
Visit the following web site for more details:
ftp://ftp-fc.sc.egov.usda.gov/WHMI/
WEB/pdf/woodduck(1).pdf
Spring 2010
Leaves
Voice
Year round Eastern United States
including Ohio, Breeding Eastern
United States, Southern Canada and
part of the west; Winter southern
United States.
Wood ducks are one of a few North American ducks
that nest in trees. They are the only North American
duck that regularly produces two broods in one year.
Nesting begins early May in Ohio. Wood ducks nest in
cavities, either natural or man made, and often take
over unoccupied cavities of a larger woodpecker, three
to 60 feet up in the tree. While they prefer to nest in
cavities over water, there have been records of wood
ducks nesting up to 1.2 miles away from water.
Tulip Valley
brian parsons
Range
Length 15-20 inches
continued on page 15
6
Usually seen in pairs, wood ducks prefer mature
riparian corridors along streams, quiet lakes or
ponds bordered by large trees, and secluded
wooded swamps. Although somewhat shy, they can
be observed feeding on a variety of nuts, fruits,
aquatic plants, seeds and aquatic invertebrates.
Acorns, seeds of bald cypress, hickory, sweet
gum, buttonbush, arrow-arum, bur-reed and wild
rice are important fall and winter foods. Juvenile
wood duck feeding habits differ considerably from
adults. Before six weeks of age, ducklings feed
consists on insects, aquatic invertebrates, small
fish and other high-protein animal cuisine.
7
partnerships
Loving Life to the Fullest
The children enjoyed picnicking at the Holden
Shelter House, reading by the lake and hiking through
vast beds of colorful spring wildflowers.
by Pam Eichenauer, director of development
class and Phi Beta Kappa.
During their daily bridge
game, she agreed to go
meet Bill only if she pulled
a red honor card. Up came
the Jack of Hearts and off
to Dartmouth she went. Bill
Steck, her “Jack of Hearts,”
became her husband in 1935.
The Steck’s first apartment
in Cleveland was small. They
lived on a strict food budget
of $1 per day. Despite the
dismal economy, she added
a cheerful touch to the
décor with daffodil curtains
and colorful upholstery.
Born in 1910 in Wilkes Barre,
While walking with a friend
Pa, Betty Armington was
and her new baby, she recalls
the elder of two daughters.
asking if having a baby was
Her parents adored the girls
Betty Armington celebrates her 99th birthday.
expensive. The response
and were able to provide
must not have daunted her
not only a loving home but also many opportunities
because soon the Steck’s had four children of their own, all
that young girls at that time could only dream of.
under the age of five. Bill, Margy, Suzy and Peter added joy
She had strong role models on both sides of her
and laughter to their happy family. In 1942 they decided
family: her father was a successful investment
to move out to the country after finding a beautiful home
banker, and her mother’s sister, “Aunt Esther”, was
in Wickliffe. The century Western Reserve farm house was
“Woman of the Year” in 1959 after growing a tiny
surrounded by 500 rose bushes, a pond, a marsh, dogwoods,
hospital in Pittston, Pa, into a world class facility.
lilacs, a vegetable garden, geese, swans and much more.
Betty Armington herself was quite a young woman
Although their own backyard was a perfect playground for
in her early years. At age 16, she took her first trip
learning and appreciating the wonder of nature, the Steck
abroad as one of 24 girls elected to represent the
family also enjoyed a unique treasure not too far from home,
United States at the International Girl Scout and
The Holden Arboretum. The children enjoyed picnicking at the
Guide Camp in Geneva, Switzerland. The camp site,
Holden Shelter House, reading by the lake and hiking through
with 27 countries represented, was located directly
vast beds of colorful spring wildflowers. Betty Armington,
behind the League of Nations building. In 1928, she
of course, jumped in with both feet and got involved as a
enrolled in Smith College majoring in economics. Her
Corporate Member. To this day she actively serves on the
dormitory room included matching floral bed linens
Holden Council and Holden’s Development Committee.
and drapery sewn by her mother, a “state-of-the-art
super hetrodine radio, a victrola, and a fancy tea cart
under the window. The summer after her sophomore
year, she again traveled abroad, attending the
University of Rouen’s extension in Brittany, France.
8
Even at a young age, Betty Armington was popular,
beautiful and had many friends. While at Smith,
a persistent friend begged her to make a trip to
Dartmouth College to meet Bill Steck, president of his
Betty, center, and her children: Margy, Bill, Peter and Suzy
In 1986, Bill Steck passed away. Ray
Armington, a successful businessman
and civic leader who served on
Holden’s Board of Directors, had
also lost his wife Elizabeth around
that same time. The two couples had
been long-time friends, once sharing
in the picking, baking and eating of
Bill Steck’s favorite elderberry pie.
Ray’s first proposal, which Betty
Armington recalls always started with
“would you consider,” was to attend
Cleveland MetroParks Zoo’s “Zippidity
Zoo Doo.” Wearing rubber-soled
shoes, he apologized for not dancing
that night, but followed up with his
second proposal to Betty, “Would you
consider taking dancing lessons at
Arthur Murray School of Dance?” Every
Tuesday, they drove to Parma for two
back-to-back lessons, each dancing
with one of the instructors, and
sharing a Coca Cola with each other
during the break. After dancing her
way into his heart, Ray Armington’s
next proposal was for her hand in
marriage. They were married in 1990
and enjoyed a short but wonderful
three years. His final proposal to Betty
Armington was, “Would you consider
taking dancing lessons again so I can
brush up on my Cha-Cha.” Moments
later he collapsed from a stroke
and passed away six days later.
Betty’s freshman dorm at Smith College
Bill, Betty and the children
Ray and Betty Armington
Her life is filled with wonderful
stories, memories and
accomplishments: from the Odyssey
Cruise she took following her
graduation from Smith College
to swimming the five-kilometer
Hellespont Crossing from Asia to
Europe in 1932. She’s also had her
share of challenges, including a
persistent bout with cancer which
resulted in the loss of her right arm
and shoulder just a few years ago.
But you would never know. Her
blue eyes still twinkle, her warm
smile still brightens the room, she
continues to enjoy the birds that
frequent her brimming feeders,
and she tirelessly gives back to
institutions she and her family have
enjoyed for many years. Through it
all, her love of her family, friends,
nature, and life have sustained
her for 99 years and counting!
Spring 2010
Leaves
The Great Depression, however, changed everything.
Many people, including her family, lost everything.
It was Woolworth stock that allowed her to finish
her college degree and proudly graduate in 1932.
These difficult times made her truly appreciate of
all the wonderful opportunities she had been given,
and this value has remained with her all her life.
jackie klisuric
Perhaps it’s the twinkle in her
sparkling blue eyes or that
genuinely warm smile. Perhaps
it’s her complete immersion in
every cause that she supports.
Or maybe, it’s her fondness
of the natural world that
surrounds her home with its
picturesque pond at the base
of the hill, rhododendrons
encircling the perimeter in
year-round green, birds feeding
just outside her dining room
window, while squirrels and
chipmunks pick up the leftovers
off the ground. It is clear that
Betty Armington loves life.
9
volunteering
Let your hands be a force of nature.
ask
Greg
by Stefanie Galbreath, volunteer coordinator
Spring is a wonderful time to see what it’s like
to be a Holden volunteer. We have several events
that are perfect one-time volunteer opportunities
to get more involved. No special training
required. Just bring your willingness to learn and
a smile.
In addition, based on
hours of volunteer service you
receive these benefits:
classes, hikes
and/or workshops
• Complimentary volunteer logo apparel
• Invitation for two to our annual volunteer
recognition and clambake dinner
Christmas Fern
• Complimentary
Call the volunteer office to sign up at one of
these events and to learn more.
Pancake Supper and Breakfast - March 12-14
Arbor Day - April 30 and May 1 and 2
Plant Sale - May 14-16
Bouquets Wine Tasting - May 29
If you’d like to become an on-going volunteer
and help out on a regular basis, please contact
the volunteer office. These opportunities include
volunteer gardeners, school guides and more.
brian parsons
Foamflower
Richard Bonnett
Q. What are some wildflowers that would be good for a
shady garden? Do you know where I can get them?
common name. Although they like moist locations, they
won’t survive in wet soils in winter.
A. There are many nice wildflowers that can be enjoyed in a
shady garden. Three of my favorites are Lobelia cardinalis
(cardinal flower), Tiarella (foamflower) and ferns such as
Polystichum acrostichoides (christmas fern).
Christmas fern gets its name from the fact that it is still
green at Christmas time. It is a clumping form that enjoys
a shady location with average to moist soils. This fern can
reach a height of 24 inches. The fronds are leathery and
lanced shaped. In spring, the fiddleheads are silvery. This
is a good plant for mass plantings and can even be used
on slopes to combat soil erosion.
Foamflower is a great groundcover for a shady garden
that is moist and has organically rich soil. It spreads by
stolosn forming 1-2’ clumps of foliage. The 4-7 lobed heart
shaped leaves turn bronze in the fall. Reddish variegation
can occur along their veins. The attractive white flowers,
rising above the foliage, are small but the stamens are
long, resulting in a foamy effect, which gives the plant its
stefanie galbreath
Cardinal Flower
brian parsons
Cardinal flowers are a short lived perennial, which can
self seed under proper growing conditions. They can
also be divided in the spring. The plant features upright
stalks that are terminated in a raceme of showy cardinal
red flowers at a height of 2’-3’. Flowers are double lipped
with 2 lobes on the upper lip and more prominent 3 lobes
on the lower lip. The cardinal flower blooms in the late
summer and is attractive to hummingbirds and butterflies.
Locate these plants in moist areas in sun to part shade.
The more sun, the more moisture they need.
David G. Leach Research Station Open Houses
(in Madison) - May 9, 15 and 16
Volunteering at Holden has many benefits.
Not only do you have the opportunity to
connect people with nature while working in
a nationally recognized museum, you have
the opportunity to develop friendships with
others who share similar interests.
by Greg Wright,
nursery supervisor
Many garden centers have some wildflowers. Try calling
before you go to see if they have what you are looking for.
The Holden Arboretum also sells a variety of wildflowers
at our plant sale in May. Take care only to purchase
woodland wildflowers that are advertised as nurserypropagated. There are often ads in magazines offering a
variety of wildflowers, usually bare root, for only a dollar
or two per plant. These have been dug in the wild, which is
detrimental to wild plant populations and habitats. Some
nurseries will pot these wild-dug plants, grow them in the
nursery for a season or longer, and sell them as “nurserygrown”. Because of their origin, these plants are also
undesirable. The only acceptable descriptor is “nurserypropagated”.the plant. Next time you want to find that
special plant, give it a try.
Display Garden volunteers, L-R, Jane Jaquays, Sarah O’Brien and Chris Barwidi
Strategic Initiative: Growing Trees & Communities
continued from page 4
New Volunteer
Orientations
Saturday, March 20
9am-noon
Tuesday, March 23
9am-noon
Saturday, April 17
9am-noon
Tuesday, April 20
9am-noon
Wednesday, May 19
9am-noon
Sunday, May 23
1-4pm
Registration is required.
10
The Volunteer Office
phone:440.602.8003
e-mail:[email protected]
The goal also includes an educational component;
with plans in place to acquire plants especially useful
for engaging and teaching children and plans for the
acquisition of books and other materials focused on
trees, regional forests, natural history and temperatezone arboriculture, and closely related subjects.
• Incorporate plants that are suitable
alternatives to invasive species
• Demonstrate which plants are useful for
attracting and supporting wildlife
• Provide examples of sustainable
garden maintenance practices.
• Allow Holden to evaluate turf-grass mixes that
would result in lower energy inputs (fertilizer,
herbicide, water) and less mowing in summer.
At the same time, the staff will be working to
keep the living plant collections free of known
invasive plants and cultivating noninvasive cultivars
of typically invasive taxa, such as Viburnum
plicatum f. tomentosum (doublefile viburnum).
jackie klisuric
Spring 2010
Leaves
contact:
As Holden moves forward, its horticulture staff will be
working to utilize the gardens and living displays to
demonstrate how to realize the many benefits provided
by plants across a continuum of built landscapes.
Display gardens in the core area will be used to
promote plants and plant combinations recommended
for sustainable home landscapes. These gardens will:
11
Modernizing a Garden Classic
by Steve Krebs, director, David G. Leach Research Station
Cultivated evergreen rhododendrons are in need
of a makeover. Since the mid–20th century they
have been broadly popular in the United States and
a mainstay of garden landscapes, but this exalted
position is eroding. Rhododendrons have lost
some of their luster in the marketplace. Recently, I
listened to a trade conference talk on recommended
plants, given by a Lake County nursery owner,
and rhododendrons were not mentioned.
What’s going on? The main problem is a static
inventory. The same cultivars that helped popularize
rhododendrons many decades ago – the so-called
‘ironclads’ with white, rose or purple flowers – are the
ones that continue to make up the bulk of commerce
today. Newer introductions with better flower colors
and foliage, such as the cold-hardy varieties developed
by David Leach and breeders in Finland and Germany,
are sold to a much smaller specialty market comprised
of knowledgeable and discerning gardeners with
the skills to grow them. Rhododendrons are finicky
plants to grow under less-than-ideal (i.e., most)
conditions and this is where the ‘old-timer’ hybrids
developed over a century ago outperform the newer
breeds. Their vigor and adaptability to a wide range
of conditions results in success for more gardeners.
These are the main considerations guiding my breeding
work at the David G. Leach Research Station. My goal
is to increase the popular appeal of new introductions
by adding disease resistance and heat tolerance to
them, traits that can improve their performance under
challenging conditions and broaden their marketability
to include the deep South (USDA Hardiness Zone 8),
regions where rhododendrons currently have a limited
presence. These traits are not independent. My working
hypothesis is that evergreen rhododendrons do not
grow well in warmer regions because they are more
susceptible to a soil disease under those conditions,
not because of direct temperature stress on plants.
If I am correct, breeding for disease resistance alone
should confer higher temperature tolerance.
A Pervasive and Persistent Pathogen
12
A majority of evergreen rhododendrons are susceptible
to the disease, but can be grown in infested soils if they
are well-drained (a disease avoidance strategy, because
free groundwater facilitates infection by swimming
fungal spores). Adding composted pine bark to the
soil mix improves performance by adding porosity
and actively suppressing the disease. These cultural
techniques are used, for example, in Holden’s Helen
S. Layer Rhododendron Garden for growing plants
on heavy soils with a high water table. Soil drenches
with fungicides can also provide a prophylactic
None of these strategies is fail-safe, and rhododendrons
would benefit greatly from an additional layer of
defense. This could be achieved by adding geneticallyconferred resistance to P. cinnamomi to cultivated
rhododendrons. Should the cultural methods of
disease control fail, the host plant would then have
genes and physiological mechanisms for minimizing
fungal damage to its root system. Transfer of host
resistance genes can be achieved by finding a good
source of resistance (rhododendron species or cultivar)
and breeding it by cross-pollination to non-resistant
plants that are ornamentally superior. Success in this
venture requires a controlled and reliable method of
screening plants for resistance, a bit of luck in finding
rare, high-level resistance, and time to grow out
generations of rhododendrons from seed to flower.
A Species for the Future
In the search for resistance, a genetically diverse
group of about 350 evergreen rhododendron
cultivars and species have been screened by handinoculating greenhouse-grown plants with P.
cinnamomi. Much of this groundwork was done in
the 1970s by researchers at Ohio State University,
and we completed a screen of more contemporary
cultivars at Holden in 2002. Fewer than five percent
of these plants proved to be resistant, and an even
smaller number were both resistant and cold-hardy,
another key requirement for our breeding program.
These disease screens provided important information
about the nature of resistance. The responses of
plants to inoculation were not discrete, either resistant
or susceptible, but continuous, ranging from very
minor damage to fine roots to necrosis of coarse
roots to plant death. This is an indication that the
resistance genes do not confer complete immunity
to the disease, and that resistance is controlled by
multiple rather than single genes. This type of partial
resistance, however, is often adequate for field-level
plant protection, and has an advantage over single-gene
resistance in being more durable, harder to overcome
by any genetic changes in pathogen virulence.
Our initial decision
was to use resistant
cultivars rather
than species for
breeding, since
they had already
been selected
for ornamental
Fig. 3 Examples of R. hyperythrum-derived F1 selections being propagated for further evaluation and potential introduction
value and had
more color than the available species – all whiteflowered. However, this turned out to be mostly a
replaced by the desired traits from the other parent.
dead end, since many of the hybrid cultivars were
In addition to root rot resistance, R. hyperythrum
either sterile or had poor breeding value – although
has many ornamental attributes – excellent foliage, a
they were themselves resistant, they were not able
dense, mounded habit, and a very floriferous nature.
to transmit this trait effectively to their progeny.
It transmits these traits readily to progeny, and tests
of its breeding value for resistance in greenhouse
In 2004, our attention shifted to a somewhat obscure
experiments suggest that first generation F1 hybrids
species from Taiwan called R. hyperythrum
between R. hyperythrum and non-resistant cultivars
(Fig. 2). Because it grows at a high elevation, it is
will have high level, if not full resistance (Fig. 2).
also reasonably cold hardy (flower bud hardy to
USDA zone 6). This species is resistant to root rot
What R. hyperythrum lacks for commercial purposes –
and was reportedly being used by a veterinarian
and is provided by careful selection of the other parent
and hobby nurseryman, John Thornton, DVM, to
in a cross – is flower color, USDA zone 5 cold hardiness
hybridize rhododendrons for his zone 8 location in
(Northeast Ohio), and a compact ‘truss’ or inflorescence
southern Louisiana. It was during a visit to his nursery,
that is the preferred standard. There are plenty of
after seeing vigorous hybrids growing in red clay
rhododendron selections and cultivars that meet
soil under a hot sun, that the connection between
these criteria at the Leach Research Station and in the
root rot resistance and high temperature tolerance
Helen S. Layer Rhododendron Garden at Holden, and
became evident to me. John gave me some of his
we have crossed them with R. hyperythrum in flower
hybrids, I acquired R. hyperythrum accessions from
color groups of pink, red, yellow, purple and white.
the Rhododendron Species Botanical Garden, and
began making crosses with them on a large scale.
In spring 2009, about 40 of these F1 crosses totaling
2,500 progeny bloomed in the field at Madison to
Promising Results
varying degrees, having been subjected to deep winter
frosts of -10 to -13F (-23 to -25C). Selections were
Breeding is simply reshuffling parental traits via
made for individuals combining cold hardiness with
genetic recombination, with the goal of creating
ornamental value. On hand to assist with evaluation
a hybrid where shortcomings in one parent are
were representatives of two commercial enterprises
interested in our plants – Briggs Nursery Inc. in
Washington State, and Plant Development Services Inc.
(PDSI) in southern Alabama. Over a dozen high quality
plants were identified, and six of these (Fig.3) were
chosen for tissue culture propagation and subsequent
evaluation at multiple sites ranging from hardiness
zones 5 to 8 where P. cinnamomi is present. PDSI will
trial the propagated plants under their production
and field conditions, and good performers will be
entered into their Southern Living Plant Collection™
under a licensing and royalty arrangement.
100%
Fig. 1 Typical field wilting symptoms due to root rot disease
(left). A chlamydospore of P. cinnamomi that is capable of
long-term survival in soils (right). It germinates and eventually
releases mobile, swimming zoospores that infect roots.
50%
25%
0%
Fig. 2 Vegetative and flowering forms of R. hyperythrum (top).
Seedlings with different levels (90) of r. hyperythrum in their genetic
constitution vary in root rot resistance (bottom) At the 50% level (a
resistant x susceptible cross) the F1 progeny are nearly as resistant
as 100% R. hyperythrum seedlings 2 months after inoculation.
Within four years, the first wave of these ‘modernized’
rhododendrons may be available to the nursery trade.
During the interim, more selections will be made from
the F1 plants and second-generation F2 populations
will be created to identify plants that have higher
resistance and more flower color saturation than the
F1s. I think of this as an R&D pipeline for ‘Leach Plus’
plants, because we’re adding landscape value to the
fine cultivars Leach created. This doesn’t mean we’ve
abandoned the ‘Leach Classics’ - we continue to select,
evaluate, and introduce fancy new plants for the
specialty market (see page 19). The real prize, however,
continues to be improved rhododendrons that are
easier to grow, have a broader, including Southern,
market, and are better positioned for a future of
climate change due to a disease resistance that confers
an increased adaptation to warmer growing conditions.
Spring 2010
Leaves
The disease problem at issue is called rhododendron
root rot, caused primarily by the soil fungus
Phytophthora cinnamomi (Fig. 1), an invasive pathogen
that affects over 1,000 plant species globally. Root rot
is the most common cause of rhododendron mortality
in commercial nurseries and home landscapes. The
pathogen enters the root system of susceptible host
plants and destroys cells during its acquisition of
carbohydrates, including the root vascular (waterconducting) structures. By the time above-ground
wilting symptoms are visible, the plant is nearly dead.
protection against the disease, and are used in
container production nurseries, but this approach is
neither effective nor advisable in home gardens.
13
Upper Baldwin
Pancake Breakfast
continued from page 5
Sharing one of Holden’s beloved traditions
These trees grow in an open field that
is now open to future uses.
“Now we have to decide what to do with it,” Gettig
said. “We have options. What it won’t be for is
planting specimen trees that no one is going to see.”
For more than 30 years, the annual Members
Pancake Breakfast has been a beloved
tradition. Who can resist the sweet taste
of maple syrup on pancakes still hot from
the grill on a cold winter morning?
The staff and resources can use the time
saved to focus on Holden’s core area, where
most of Holden’s guests can be found.
This year, The Holden Arboretum is
saying “the more, the merrier” with a
reinvigorated pancake breakfast, which
will be held on, Saturday, March 13
and Sunday, March 14, by opening up
ticket sales to non-members as well.
We had the area so we planted it, but we were
spreading the staff far and wide, we were spreading
our resources far and wide,” Gettig said. “We’re
gearing up and when it comes time to implement
the core area master plan, we’ll be ready.”
But when it comes to the pancake
breakfast, membership will still
have its privileges. Members will
have the first opportunity to make
reservations starting on Feb. 1 and
running until March 8. Non-member
reservations will open on Feb. 22.
The Friday, March 12, Pancake Supper
and evening hike will still remain a
members-only exclusive. This evening
event features an expanded menu,
entertainment and an evening hike
on the grounds. Members attending
the breakfast on Sunday, March 14 will
have the opportunity to visit a nearby
sugarbush owned by Tom Offutt, where the
syrup served at the pancake breakfast is
harvested. Learn how maple syrup can be
produced using sustainable, tree-friendly
techniques that preserve the sugar maples.
ryan somma
Liriodendron tulipifera (tuliptree)
continued from page 6
Collection in October 1970. This lowbranched specimen now measures 42’
x 41’ with a diameter of 19.7” at 2’. The
leaf variegation is more prominent in
spring, and fades to a yellowish-green.
The attractive leaves of mature trees are
about 4” long and wide, but can be as
much as 8” on young fast growing trees.
Insects rarely feed on the foliage, with
notable exceptions of tiger swallowtail
butterfly and promethea silkmoth
larvae. In the woods they provide the
last spectacular display of fall color in
November with a number of trees also
turning color in late October. Trees in our
gardens often defoliate significantly during
summer dry spells. In cultivation they may
also suffer from infestations of tuliptree
scale insects and aphids that exude sticky
“honey-dew” that sooty mold grows on,
marring the foliage and all surfaces below.
Visit Tom Offutt’s beautiful Sugarbush
photographs by jackie klisuric
For more information on the breakfast, hikes or members only activities, visit holdenarb.org.
alex lomas
Leaves
14
Tuliptrees can be difficult to transplant
due to their rather coarse fleshy roots,
and are best planted in small sizes in
spring. They resent cultivation around
their roots, soil compaction, pollution,
salt, drought and waterlogged soil. Whitetailed deer favor this species as browse.
Around healthy tuliptrees it can be a
challenge to grow companion plants such
as rhododendrons as the root system
so aggressively competes for water.
Liriodendron tulipifera is one of our most
majestic eastern North American natives
with the tallest at 178’ in western North
Carolina. Being in the magnolia family it
is one of the most ancient flowering trees
In 1999 Holden’s Plant Collections
Curator, Charles Tubesing obtained
pollen from Chinese tuliptrees originating
from Huang Shan and Lu Shan in Anhui
and Jiangxi Provinces and made crosses
with our natives on the edges of fields in
Holden’s Baldwin property. The seedlings
were container grown and planted in late
June 2002 when they were 5’-6’ tall. To
date, there has been no mortality. The
17 hybrids now in our collection average
25’ in height, 6 being 30’ or more. Five of
the trees flowered in 2009. The flowers
on the trees south of the Cooper Building
parking lot were more orange than green
and more diminutive than those of their
seed parent. The tallest of these 10 year
olds is in an old pasture at Lantern Court
measuring 38’ x 17’, 6.8” DBH — diameter
at breast height and has borne about 20
fruit in 2009. The new leaves of these
hybrids often have a purplish blush just
like their pollen parent. These hybrids
display the vigor that was the main
reason for making the cross, along with
the hardiness of our native tuliptree.
Spring 2010
Non-members and members alike
will also have the opportunity to
explore Holden’s grounds on guided
hikes planned for Saturday, March
13, and Sunday, March 14. Enjoy
a brisk hike to either work up an
appetite before breakfast or burn
off the calories afterwards. These
hikes, lead by members of Holden’s
education staff and volunteers, are
designed to revive the senses and
provide a new perspective on the
natural world. See what is starting
to bloom, what animals are out
and about, and how much activity
takes place at Holden, even as
early as March. It will be a chance
to see that spring is on the way.
as the genus dates back more than 90
million years. Although called tuliptree
by horticulturists, it is also referred to as
tulip-poplar, yellow-poplar and whitewood.
Known as Ko-yen-ta-ka-ah-tas (the white
tree) by the Onondaga, its scientific name
was assigned by Linnaeus (tulip-bearing
lily-white tree). It is the state tree of
Indiana, Kentucky and Tennessee. Our
species has an endangered counterpart
in China, Liriodendron chinense.
15
Plant Introductions at Holden
by Mary Topa, PhD, director of research and Steve Krebs, director, Leach Research Station
As a plant institution, The Holden Arboretum is the
owner of many one-of-a-kind plants representing
unique genotypes. These plants originate from
several sources. They occur naturally in our land
holdings, are brought here from collection trips, or
are grown on site from random-pollinated (insect/
wind) or controlled-pollinated (hybridized) seed
using plants in our collections or elsewhere.
The question arises whether any of this unique
diversity can serve Holden by being exploited for
purposes beyond our geographical boundaries,
serving a broader regional, national or international
interest. Plant breeding/introduction activities at
public gardens generally focus on the introduction
of cultivars with high perceived value because of
Plant introduction also enhances the diversity
of Holden collections. Selection of plants for
introduction requires a diverse array to choose
from. Whether this diversity is generated from
wild collections or from hybridization (genetic
recombination), Holden benefits from the
commercial, research or educational potential
of the collection. Plant introduction can provide
monetary compensation from revenues (royalties)
received from valued plant introductions over
a finite period of time. While this income is
important for furthering horticultural research
at Holden, the primary goal of the breeding
program is the introduction of new and
improved plants for public use and enjoyment.
In 2007, an ad hoc Plant Introduction
Committee was formed at Holden
consisting of representatives
from Holden staff, Holden board
members, local nursery owners
and academic horticulture. It was
the committee’s job to review
Holden’s Plant Introduction Program
and draft plant introduction
guidelines, using the David G.
Leach rhododendrons as our
model. This came at a critical time
since Holden wanted to introduce
several of Leach’s selections that
he did not live to fully evaluate.
Two cold-hardy selections with
particular ornamental merit have
been recently named and entered
into the International Rhododendron
Register: the yellow-flowered
hybrid Rhododendron ‘Holden’s
Fig.1 New cold-hardy rhododendron cultivars that were hybridized by David G.
Solar Flair’ and a large-leaved,
Leach and introduced posthumously by Holden. Left: a fancy yellow-flowered
early-bloomer named R. ‘Holden’s
creation named r. ‘Holden’s Solar Flair’. Right: r. ‘Holden’s Spring Herald’ is an
Spring Herald’ (Fig.1). In both
early blooming, large-leaved hybrid.
cases, Leach is the breeder of
record, and Holden is recognized
their potential use in large numbers over a wide
as the evaluator and introducer.
area or specific region. However, there is increasing
There are over a dozen more of these ‘Leach
emphasis on the introduction of material with
classic’ selections – cold-hardy in zone 5 and
non-horticultural plant uses, such as native plants
highly ornamental – under consideration for
of local origin that are used in the conservation
future introduction. Concurrently, a new breed
and restoration of native plant ecosystems.
of rhododendrons is being developed at Holden
16
Enjoy the beauty of Spring at Holden
that adds disease resistance and heat tolerance
to the cold-hardy cultivars created by Leach and
other hybridizers (see page 12). Still in the early
stages of propagation and off-site evaluation,
the first wave of these plants has the potential
for a bigger market than the current Leach
cultivars, more revenue generation, and more
institutional recognition. Our hope is that success
in this rhododendron breeding venture will
provide a model for research and development
of other important landscape plants at Holden.
Spring 2010
Leaves
PHotos these pages by jackie klisuric
Holden aims to introduce landscape plants that are
“widely planted and renowned for thriving despite
severe environmental stresses” (Leaves, Fall 2009,
page 4). Why? Public enjoyment of a Holden
introduction is an effective way to achieve broad
institutional recognition. Plant introduction also
promotes collaboration with peer institutions
that have their own research and development
programs. Holden currently evaluates plants
from academic, non-profit, and governmental
institutions that have their own introduction
programs. By sending out, as well as receiving
plants for testing and evaluation, Holden fulfills
its role as an important horticultural resource.
17
shorts
Holden creates bluebird database
A bluebird database, developed by
Michael Watson, conservation biologist
at The Holden Arboretum, is now helping
bluebird volunteers track data.
the staff’s ability to locate information
about specific years, trails, nestboxes and/
or species with the click of a button.
Since the start of the bluebird program in
the 1960s, Holden has sent data to Cornell
University’s Lab of Ornithology each year.
And bluebird volunteers have calculated
year-end summary statistics for each of
those years. But until recently, the data have
never been compiled into a single electronic
source. In 2008, Holden’s conservation
staff developed the database, improving
Plant Sale
john benson
Mother’s Day Brunch and Garden Tour
May 9, 10am, 1pm and 3pm seatings. For details go to holdenarb.org
Holden hires new lead horticulturist
Woodland 5K Run/Walk
said. “In fact I have used some photographs
I took of the prairie plantings in lectures I
have given. And I was excited with the
idea of working here where there is this
wonderful blend of trees and herbaceous
perennials, not found in most arboretums. I
am also impressed with the forward thinking
of Holden and how it is developing plans for
its future to support ecology, environmental
issues and gardening in today’s world. Not
an easy task.”
Viki Ferreniea joined the staff of The Holden
Arboretum in January as the organization’s
lead horticulturist.
The former director of horticulture for the
New England Wildflower Society, Ferreniea
is a graduate of Swanley Horticultural
College in Kent, England, and received the
National Diploma in Horticulture from the
Royal Horticulture Society. She trained at the
Royal Botanical Gardens at Kew, England,
where she first began her love affair with
North American wildflowers. The creator
of the North American wildflower garden
at Longwood Gardens near Philadelphia,
Pa., she has lectured on and taught about
wildflowers all over the country.
Leaves
18
“I have been visiting Holden over many years
whenever I was in the general area and was
impressed with it from the start,” Ferreniea
Ferreniea brings many years of experience
in the cultivation and management of a wide
range of plants, their selection and evaluation
for garden worthiness and marketability.
She’s
also
had
extensive
hands-on
involvement with the design, installation and
maintenance of diverse gardens, renovation
and expansion of mature gardens and the
rejuvenative pruning of woody plants. She
is the author of Wildflowers in Your Garden,
published in 1993.
Bouquet’s Wine Tasting
Cytisus Hirsustus (broom)
Arbor Day
Don’t miss our Spring Events
Spring 2010
While she has just joined the Holden staff,
she is no stranger to its grounds.
During her career she worked for several
years with the Breck’s Bulb and Springhill
Nurseries divisions of Foster and Gallagher,
where she managed the research and
development program, finding new plants
and bulbs and evaluating them for garden
worthiness and marketability. She also
has managed a private estate garden for a
Connecticut family, served as perennial trials
manager in New Hampshire, and was the
horticultural manager of a start-up organic
farming operation in Maine.
19
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pancake breakfast
yum!
Nothing is better than hot pancakes dripping with sweet maple
syrup. This year we have something special planned with
guided hikes allowing you to explore the grounds before or
after your breakfast reservation. It’s a perfect way to work
up an appetite or burn off a few calories after breakfast.
For details on this year’s Spring Hikes and Pancake Breakfast
event, see page S11 or visit us online at holdenarb.org.