I’ve been lucky the last couple of days to be out of my office and in the collections preparing for the Witch Hazel Family Seminar tour. Hamamelis is one of my favorite groups of woody plants. As I’ve spent more time studying this genera, I have noticed how varied the blooms and even the fragrance of the different cultivars can be. The following are what I think are the most fragrant witch hazels in our collection.

Fragrant planting of Hamamelis vernalis along Sharples Dining Hall. photo credit: R. Maurer

One of the best scents on campus right now is between Sharples Dining Hall and a stand of Hamamelis vernalis .  Also known as the spring witch hazel and reaching a height of nine feet, H. vernalis blooms with small red-to-yellow flowers as early as December. While not known for its floral display, many of H. vernalis cultivars are known for the best fall color among witch hazels including: H. ‘Autumn Embers’ and H. ‘Sandra’.

Hamamelis x intermedia 'Early Bright' espaliered in the Thersea Lang Frangance Garden. photo credit: R. Maurer

A stroll into the Fragrance Garden engulfs you in a fragrance of Hamamelis mollis ‘Early Bright’, a Scott Arboretum introduction. A fantastic, mature specimen is espaliered against the wall of Clothier Hall. A cultivar of the Chinese witch hazel, H. ‘Early Bright’ was selected because its vibrant yellow blooms enliven the landscape two weeks earlier than other H. mollis.

Hamamelis x intermedia 'Early Bright' photo credit: R. Maurer

Hamamelis x intermedia, the hybrid witch hazel, is a cross between H. japonica and H. mollis originally crossed in 1928 at the Arnold Arboretum. Ranging from deciduous shrub to small tree, H. x intermedia hybrid is always among experts favorite witch hazel cultivars. Some of the newer introductions are quite fragrant.

In the lawn near the Cornus florida var. rubra on the north side of Kohlberg Hall you’ll find Hamamelis × intermedia ‘Fire Blaze’. It is still a small specimen but smells great and has pretty apricot-orange blooms. As with most H. x imtermedia cultivars, ‘Fire Blaze’ blooms from February to March with a great vase-shaped habit.

Hamamelis x intermedia 'Strawberries and Cream' photo credit: D. Mattis

Walk down Metesequioa Allée towards Clothier Hall and make a point of getting up close to Hamamelis × intermedia ‘Strawberries and Cream’. I don’t know if it is psychological but to me it really does smell deliciously like strawberries and cream! The flowers are beautiful too with a mixture of soft red and pale yellow – also reminiscent of a strawberry. A rounded shapely shrub, ‘Strawberries and Cream’ blooms from February to March.

Lastly, tucked in the Pinetum is a small specimen of Hamamelis × intermedia ‘Orange Peel’. This is another one that I think may be playing with my senses, but to me, it really does look and smell like little bits of orange zest. An 1988 introduction from Kalmthout Arboretum of Belgium, ‘Orange Peel’ not only has large pale orange flowers, it displays good fall color.

Be sure to come out to the Scott Arboretum today before these unusually beautiful, and very fragrant blooms fade away. P.S. – Catch another great scent currently floating around the Arboretum office and the Winter Garden – Chimonanthus praecox ‘Luteus’.

As the snow melts and you begin your garden clean-up, I am sure you are reviewing your spring to do list. Plants to be divided or removed, as well as garden holes to be filled with new plants. As you prepare your plant wish list here are three shrubs to consider adding to your garden.

Chaenomeles speciosa 'Cameo' photo credit: R. Maurer

Chaenomeles speciosa ‘Cameo’ a selection of the flowering quince blooms very early in the spring with striking salmon pink flowers.  In the Swarthmore area most of the flowering quinces come into flower around the end of March into early April.  While many of the flowering quince cultivars can get quite large, ‘Cameo’ matures to only four to five feet tall.  The flowers appear before the foliage.  The branches can be cut and used in flower arrangements; in particular they are a favorite species for Ikebana.  For the best flowering, plant in full sun.

Hydrangea arborescens 'Hayes Starburst' photo credit: Spring Meadow Nursery

Hydrangea arborescens ‘Hayes Starburst’ is a relatively new selection of the native, smooth hydrangea.  This double flowering form was selected by Hayes Jackson at his garden in Anniston, Alabama.  At maturity ‘Hayes Starburst’ will reach three feet tall with an equal spread.  In the wild, Hydrangea arborescens grows in the deep shade, however for best flowering plant in partial shade to full sun.  Hydrangea arborescens blooms on new “woods”, therefore in late winter the stems can be pruned nearly to the ground; the plants will regenerate and flowering will occur the same season.

Abelia mosanensis photo credit: Spring Meadow Nursery

Abelia mosanensis, the fragrant abelia is a wonderful late spring flowering shrub.  The tiny white flowers with a flush of pink are very fragrant as the common name would suggest.  In the fall the glossy foliage turns a beautiful orange-red.  This shrub will reach five to six feet tall, but the size can be manipulated with judicious pruning.  For the best flowering and fall color, plant in full sun.  Like other abelias, this species grows well in tough urban conditions.

Members of Scott Associates will have a choice of these three plants as their spring dividend at the Spring Festival on Sunday, March 14 at 4 pm. If you would like to receive the annual spring dividend, become a member of the Scott Associates. Let us know what other great plants you are planning on adding to your garden this spring.

You may have noticed on the back of many catalogs and mailings from environmentally conscious companies, the FSC logo pictured above. The Scott Arboretum has been printing the Hybrid and many brochures and invitations with this logo since Fall 2006. The FSC logo is most recognizable on printed materials, but are you aware of what this logo represents?

Cover of the 2010 Spring Hybrid.

The FSC or Forest Stewardship Council logo indicates the publication has been printed on paper that has been harvested, milled, and printed in an environmentally responsible, socially beneficial, and economically viable way.

FSC oversees more than the production and printing of paper. It is an international non-profit organization devoted to encouraging the responsible management of the world’s forests. Thus the products certified by FSC are not limited to paper.

FSC logo stamped on MDF (medium density fiberboard) used in the construction of the Wister Center. photo credit. R. Robert

Because of the FSC’s commitment to environmentally responsible stewardship of our forests, it was a great source of building materials for the new Wister Center. Using sustainably harvested materials is a component of building a LEED-certificated building.

You can see FSC MDF being used as a building material in the skylight of the headhouse. photo credit: R. Robert

As a percentage of the total cost, 42% of the wood used in the Wister Center was FSC. These items can be found in the attractive Douglas fir decking, glu-lams, molding, and framing which accent much of the Wister Center. In addition FSC MDF (medium density fiberboard, an engineered wood product), can be found underneath many decorative elements of the Wister Center.

FSC douglas fir molding and framing was used to give the Wister Center its finished look. photo credit: Archer and Buchanan

]]> http://blogs.scottarboretum.org/gardenseeds/2010/03/fcs-wood/feed/ 0 http://blogs.scottarboretum.org/gardenseeds/2010/03/innovation/ http://blogs.scottarboretum.org/gardenseeds/2010/03/innovation/#comments Wed, 03 Mar 2010 18:46:15 +0000 Becky Robert http://blogs.scottarboretum.org/gardenseeds/?p=1925

When designing a LEED-certified building there are many strategies such as storm water management techniques, recycling materials from construction, and maximizing the use of natural light to light the building, that will help accumulate points needed to receive LEED certification. In addition to these established and recognized practices, the certification process awards points for innovation. This ability to innovate new green designs and techniques is what is driving the continually evolving green industry.

Upon embarking on the design of the Wister Center, there was much discussion about the techniques and the associated costs for heating and cooling the building in a…

When designing a LEED-certified building there are many strategies such as storm water management techniques, recycling materials from construction, and maximizing the use of natural light to light the building, that will help accumulate points needed to receive LEED certification. In addition to these established and recognized practices, the certification process awards points for innovation. This ability to innovate new green designs and techniques is what is driving the continually evolving green industry.

Upon embarking on the design of the Wister Center, there was much discussion about the techniques and the associated costs for heating and cooling the building in a sustainable fashion. An idea garnering much support as a sustainable technique, but an expensive method, was a ground source heat pump system. The majority of the cost for this proposal was in the drilling of several 100-foot deep wells beneath the site to serve as an area for heat exchange.

Thomas Cochrane and Rhoda Maurer discuss the inner workings of the Wister Center. photo credit: R. Robert

Following one of these discussions, Swarthmore College’s Senior Project Manager for Mechanical Systems, Thomas Cochrane, was struck with an innovative idea which addressed the needs of the whole campus, not just the new Wister Center. Dubbed the Total Campus Perspective (TC system) by the project engineers, this design provides a synergistic solution that benefits the Wister Center and the campus as a whole.

Ground source heat pump system illustration from the International Ground Source Heat Pump Association.

Using the ground source heat pump system during the winter months, water is circulated beneath the earth’s surface through plastic pipes and where it is heated by the constant temperature of the earth (50 to 55 degrees). This heated water is carried back into the building to the heat the space. During the summer months, the system is reversed. The water pulls heat from the building where it is discharged into the cooler temperatures of the earth.

Thomas Cochrane recognized the existing chilled water loop on campus could provide a similar function as the earth in the ground source heat pump system for the Wister Center. During the winter months, the Wister Center can use excess heat collected from other locations on campus where cooling is occurring (such as computer rooms, electrical rooms, and mechanical rooms) to heat the building.

Tapping into the heated water from the chilled water loop on campus offsets the operation of the central plant chiller which would be responsible for chilling the water. According to the project engineering team, there is a savings of 1,639 ton-hours each winter season for the central campus chiller plant.

Mechanical room where the TC system is housed in the Wister Center. photo credit: R. Robert

During the summer, the Wister Center rejects heat to the return side of the chilled water loop with the MacCabe library cooling loads, where the Wister Center is connected to the campus chilled water loop. It is estimated this adds 1379 ton-hours each summer season to the central campus chiller plant. Thus the net impact on the central chiller plant is an annual savings of approximately 260 ton-hours.

In addition to these savings, there is an earth exchange component to the system. Six hundred and fifty feet of buried piping that connects MacCabe Library and the Wister Center, aid in transferring heat to the earth. Therefore, it is providing further reduction to temperature of the water circulating between buildings in the summer and increasing the temperature the water in the winter, again benefiting the load to the central campus chiller plant.

The engineers estimate this innovative system is a 39% improvement over traditional rooftop air unit systems and a 1% improvement over traditional ground-coupled heat pump systems.  The TC system takes advantage of mechanisms already in place on campus to heat the new Wister Center and provide energy saving to the college as whole.

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When all of the deciduous trees drop their leaves in the fall we get the opportunity to admire the bareness of a landscape.  There is something very pure about observing the structure of a tree, the sprawling nature of its branches, with the overall stature contrasting against the gray sky.   In the winter, however, after a beautiful snow, we also look downwards. Silhouettes of smaller trees and shrubs become apparent against a pristine white backdrop.  Today, I was walking past the fraternity houses, admiring the spectacular Hamamelis display, when I saw the outline of Zanthoxylum simulans.  The lateral spines weren’t exactly welcoming, but they were certainly captivating.  I commonly see our native species, Zanthoxylum americanum or flatspine prickly-ash at arboreta, but this specimen deserves more attention.

The formidable thorns of flatspine prickly-ash. photo credit: S. Keitch

If you’re like me and don’t like people poking around your garden, then the flatspine prickly-ash isn’t just a beautiful small tree, but a functional addition to your strategic home defense plan.  The thorns may reach an impressive size of three quarters of an inch, large enough to be a visual deterrent.  Other possible plants to bolster your living barrier include the hardy orange, Poncirus trifoliata, the wintergreen barberry, Berberis julianae, or the Devil’s walking stick, Aralia spinosa.

Multiple lead trunk of Zanthoxylum simulans. photo credit: S. Keitch

All kidding aside, the overall form of Zanthoxylum simulans is graceful, with its multiple lead trunks striving upwards of fifteen feet. I slightly favor the finer branches because the thorns appear even more pronounced.

As a member of the citrus family, or Rutaceae, flatspine prickly-ash possesses a common citrus family characteristic of aromatic foliage when crushed.  The compound foliage is a lustrous green tone that complements the inflorescences, which turn a beautiful pinkish-red in the late summer.  However, it is the fruit, namely the pericarp, which is sought in Asia for its medicinal and flavoring properties.  The common names including the word ‘pepper’ are derived from the culinary use of the dried fruits as seasoning herbs, described as more pungent than black pepper.

Close-up of the surly nature of Zanthoxylum simulans. photo credit: S. Keitch

If you want to try something a little bit different, I would recommend any of the Zanthoxylum species. They are an interesting specimen for tough conditions.  Of course, I must warn you of their surly nature and to be mindful of where they are located.  During my first encounter with Zanthoxylum simulans, I was left with a painful impression that I will never forget.

Today, the Bald Eagle population is approximately 70,000 with about half of this population living in Alaska.  Locally, fairly large numbers of eagles can be viewed at the Conowingo Dam in Maryland.  However, eagles can be seen all over the Delaware Valley including places such as the Tyler Arboretum, Philadelphia Naval Yard and the John Heinz National Wildlife Refuge at Tinicum.

Bald Eagle soaring over Scott Arboretum of Swarthmore College. photo credit: S. Keitch

Bald Eagles were declared an endangered species in 1967 under a law that preceded the Endangered Species Act of 1973. The Bald Eagle was listed as endangered in 43 of the 48 lower states.  In July 1995, the endangered status was upgraded to threatened.  On June 28,  2007, the Bald Eagle was officially taken off the Endangered Species List.  However, it is still protected by the Bald Eagle Protection Act.

A bird list of Swarthmore College and the Crum Woods can be accessed by referencing the Conservation and Stewardship Plan for the Crum Woods of Swarthmore College, 2003 in Appendix G: Bird Species in the Crum Woods.

For additional information one of the very best resources for bird related information is the Cornell Lab of Ornithology.

After the large snow fall we had on February 5^th and 6^th you have probably looked outside and have observed many of your prized plants are engulfed in snow.  In most cases the snow will fall off the plants and they will spring back to their natural and original shape.  However, there are some plants which are especially vulnerable to heavy snows.  Several pines including the lacebark pine (Pinus bungeana) and especially the Eastern white pine (Pinus strobus) can have large branches snapping off at the trunk from the weight of the snow.

Most evergreen conifers, however, that have a strong central leader, such as: Japanese red-cedar (Cryptomeria); fir (Abies); spruce  (Picea); and cedar  (Cedrus) can be covered in snow without it causing a serious effect.  Multiple trunked conifers, such as, juniper (Juniperus); Leyland cypress  (xCuprocyparis) and arborvitae (Thuja) often have the multiple leaders splay open in a heavy snow.  In the case of the aforementioned conifers , it is advantageous to try to knock the snow from the branches to avoid the leaders from splaying open.  The damage can be irreparable from a heavy snow load.

Pinus mugo ' Enci' in the John W. Nason garden after an inch snow on February 3. photo credit: R. Robert

Most shrubs have an amazing capacity to recover from very heavy snows.  Multi-stemmed broadleaved evergreens such as inkberry (Ilex glabra);  heavenly bamboo (Nandina domestica); common boxwood (Buxus sempervirens); Mahonia japonica; and M. bealei “catch” the snow.  This often causes the branches to open up and be pinned to the ground with the weight of the snow.  If you are fearful that the weight of the snow may be doing damage,  gently brush the snow from the plants with a broom.  However, I have found that allowing the snow to melt and alleviate the weight, the plants will spring back without any permanent damage to their structure.

The same Pinus mugo 'Enci' as pictured above after a 28.2 snow on February 6. The branches are splayed open from snow load. Hopefully this plant will spring back after snow melt. photo credit: R. Robert

All perennials will be perfectly fine under the layer of snow.  Even newly emerging flowers such as the Lenten rose (Helleborus xhybridus) will be insulated by the snow and flower in profusion once the snow has melted.

Once the snow begins to melt gardeners should be mindful of snow and giant icicles melting from roofs and dislodging with great force and weight. This can often crush the plants below.  Unfortunately, like the large breaking branches of the lacebark pine and the Eastern white pine there is not a lot that can be done to avoid is collateral damage. However, I suggest don’t park your car under a white pine during a snow storm!

Nether Providence Township has recently established Heritage Tree designation for some of the oldest or most distinctive trees in the township. This designation was adopted last year by the Nether Providence as part of the revision to their Shade Tree Ordinances.  Heritage trees are protected by township law and a township permit must be filled out by the property owner and reviewed by the Shade Tree Committee before removing, or pruning more than 20% of a Heritage Tree within a twelve month period.

The following defines a Heritage Tree:

1)      A tree 36 inches or greater dbh (diameter at breast height; note: 36 inches in diameter is approximately nine feet and four inches in circumference)

2)      A tree of exceptional age or species regardless of its size.

3)      A historic tree connected to a notable or regional historic event, person, structure, or landscape.

To establish a list of Heritage Trees, the Nether Providence Shade Tree Committee is conducting a Heritage Tree Survey in the township.  This survey will include an assessment of nominated or potential Heritage trees on both private and public lands.  The survey will identify the tree species, dbh, circumference, GPS location, etc.

Andrew Bunting posing with Quercus falcata. photo credit: T. Hawkins

On Sunday, January 31^st, I conducted some Heritage Tree survey work with Thomas Hawkins who has worked extensively on both the Nether Providence Street Tree ordinances as well as the Heritage Tree Program.  He wanted to assess some of the lands owned by Swarthmore College which are in Nether Providence.  Essentially, the Crum Creek forms one of the boundaries of Nether Providence, therefore, the woodlands situated between Crum Creek at Avondale and Turner Roads, including “the ruins;” composting area, nursery, and Clark House all are within Nether Providence Township.

It was a beautiful day to look at trees, despite a starting temperature of fourteen degrees and a light layer of snow. We began our survey just above the Dam Site, a small stone house that sits next to the waterfall above the Yale Avenue bridge.

I had wanted to look at a population of Quercus falcata, Spanish red oak which exists in the woods above the Dam Site.  While Quercus falcata is native to this part of Pennsylvania, its populations are very rare in Delaware County. Thomas and I found about two dozen very large specimens, some of which will become Heritage Trees.  The largest specimen has a dbh of 3.2 feet.  These plants are growing amongst other oaks including the white oak, Quercus alba and the red oak, Quercus rubra, as well as significant populations of the American beech, Fagus grandifolia.

Thomas Hawkins providing perspective of an Acer saccharinum. photo credit: A. Bunting

Cresting the hill we headed to the Crum Creek flood plain just below Strath Haven Condominiums.  This area is overgrown with many invasive exotics, especially Japanese knotweed, Polygonum cuspidatum.  However, rising amongst the knotweed is a fantastic specimen of silver maple, Acer saccharinum.  Both silver maple and red maple, Acer rubrum are lowland species of maples often found growing along streams and rivers.  This silver maple has a dbh of 4.6 feet.

We skirted the wooded hillsides spilling down to Crum Creek and recorded several Heritage Tree specimens of the tulip tree, Liriodendron tulipifera, which is one of the dominant trees of the Crum Woods.  We recorded the measurements of a magnificent specimen of white ash, Fraxinus americana. As we headed north, we passed an old planting of Norway spruce, Picea abies, by an old ruined garden simply known as “the ruins.”  As we approached the train trestle we spotted a red oak, Quercus rubra that towered well above the trestle.  This specimen has a dbh of 4.9 feet.

We ended our survey around noon at the train trestle.  Thomas and other members of the Shade Tree Committee will go back another day and continue this survey northwards beyond the trestle and following  Crum Creek to Plush Mill Road.  We could see in the distance several more tulip trees that will undoubtedly become Heritage Trees.

By: Barbara Kingsolver

Well-known novelist Barbara Kingsolver takes us on a different journey in her memoir Animal, Vegetable, Miracle: A Year of Food Life. Kingsolver and her husband and two daughters move from their Tucson, Arizona home of many years to a farmhouse in the southern Appalachians. One of the main reasons for their relocation was their desire to live in a place that could sustain them. The family decided to spend the following year trying to the best of their ability to grow everything that they eat and if they can’t, buy it only from a local farmer.

The concept may seem foreign to most of us living in the modern food system, but really it is the most basic form of healthful living: understanding where all of your food and water comes from and eating a seasonal diet based on locally supplied vegetables and meats. For gardeners this book is educational as well as entertaining because Kingsolver’s expert gardening abilities play a major role in the family’s ability to survive off the land. If anything, this book will help to open your mind to exactly where the food you eat comes from and to begin to think about what the costs are to the environment and your body from food that comes from far away.

This book will be discussed on Tuesday, February 9, Noon to 1 pm as part of the Scott Arboretum’s Nature’s Narratives Book Discussion Group. Also check out the other must-reads as part of this group!

The Scott Arboretum’s Garden Seeds has been named in the top 100 great sites for gardeners by XRAY Technician Training. While this not a traditional gardening blog, we are listed with the garden blog giants like Garden Rant, A Way to Garden, and Sustainable and Urban Gardening. Let us know what you would like to read more about on Garden Seeds.