October Color Appears at the Washington Park Arboretum (Part II)

October 27th, 2014 by UWBG Arborist, Chris Watson
Selected cuttings from the Washington Park Arboretum (October 20 - November 2, 2014)

Selected cuttings from the Washington Park Arboretum (October 20 – November 2, 2014)

1)   Euonymus hamiltonianus subsp. sieboldiana                      (Siebold’s  Euonymus)

  • Native to the eastern Himalaya 1
  • Ornamental seed pods on display in autumn months 2
  • Specimen located in the Spindle Tree Collection

 

2)   Illicium henryi      (Henry Anise Tree)

  • Native to western China 1
  • Red summer flowers turn to star-shaped fruits in autumn
  • Specimen located along Upper Trail near the Asiatic Maple Collection

3)   Lithocarpus henryi      (Longleaf Chinquapin)

  • Native to central China 1
  • Notable for “laurel-like, narrow, glossy leaves” 2
  • Specimen located along the Lower Trail near the Sino-Himalayan Hillside

4)   Osmanthus yunnanensis      (Chinese Osmanthus)

  • Native to southern China 1
  • “Less cold-hardy” than other Osmanthus species in Seattle 2
  • Specimen located in the Sino-Himalayan Hillside

5)   Polyspora kwangsiensis      (Fried Egg Plant)

  • Relative of the Camellia and Stewartia 1
  • Camellia-like flowers appear in autumn 1
  • Specimen located along Upper Trail near the Camellia Collection

 

1 Bean, W. J., and George Taylor. 1970.  Trees and Shrubs Hardy in the British Isles.  London: J. Murray.
2 Jacobson, Arthur Lee. 2006.  Trees of Seattle.  Seattle, WA: Arthur Lee Jacobson.

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Autumn Is Amazing

October 18th, 2014 by Catherine Nelson, Adult Tours Program Assistant

liquidambfallcolorThe Liquidambar styraciflua, or Sweetgum, is one of autumn’s most brilliantly colored trees, its leaves showing off every color in the spectrum.

The Liquidambar was wide spread, existing all over the Northern Hemisphere during the Tertiary Period (250-65 million years ago), but mostly disappeared due to glaciation during the ice age. Now this tree is native only to the SE United States and some areas of Mexico and Central America.  These deciduous trees can grown to 80-100 feet tall & live up to 400 years.  Its species name in Latin means ‘flowing with resin’ as the sweet resin in this tree was originally used for chewing gum.

They can be mistaken for maples as they have a similar palmate leaf. The Sweetgum leaf has 5-7 pointed lobes, but is usually flat along the bottom. They also have a distinctive spiky  brown fruit in autumn.

Our free Weekend Walks 10/19 – 11/16 will take visitors to view this and other deciduous plants in our collection.  Please join us.  See Visit > Tours for more information.

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October Color Appears at the Washington Park Arboretum

October 10th, 2014 by UWBG Horticulturist
Selected cuttings from the Washington Park Arboretum (10/6/14-10/19/14)

Selected cuttings from the Washington Park Arboretum (10/6/14-10/19/14)

 

 

 

 

 

 

 

 

 

 

1)   Franklinia alatamaha

Close-up photo of Franklinia flower

Close-up photo of Franklinia flower

  • Native to the Alatamaha River, Georgia, and discovered in the late 18th.
  • Genus contains just one species, and has long been extinct in the wild. Today’s plants all descend, it is believed, from those cultivated in Philadelphia under the name chosen by William Bartram in honor of Benjamin Franklin.
  • Specimen located along Arboretum Drive near the Camellias.

2)   Ilex crenata      ‘Mariesii’

Close-up photo of Rehderodendron seed pods

Close-up photo of Rehderodendron seed pods

  • A very slow-growing female holly with tiny leaves and black fruit. Collected in Japan around 1890 by Charles Maries and sent to Veitch Nursery.
  • Located within the Asian/North American clade in the Holly wedge.

3)   Rehderodendron macrocarpum

  • An upright deciduous tree with red young shoots and glossy dark green leaves.
  • Native to western China, seeds from macrocarpum were first collected in 1932 from a fruiting specimen on Mount Omei in the Szechwan Province.
  • This specimen is located in grid 36-B, northwest of the Winter Garden.

4)   Sorbus helenae

  • Very distinctive species only recently introduced to cultivation. White fruits and autumn leaf color make helenae an attractive tree this time of year.
  • Located about midway through the Mountain Ashes, west of the path.

5)   Viburnum odoratissimum

  • A vigorous, bushy evergreen shrub with glossy, dark green leaves and red fruit ripening to black.
  • Native to India, China, Burma, Philippines, and Japan.
  • Located in grid 12-8E along Arboretum Drive.
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October 2014 Plant Profile: Amaryllis belladonna

October 1st, 2014 by Soest Gardener, Riz Reyes

IMG_7256A large indoor bulb that’s forced to flower in time for the holidays is often what gardeners think of when we say “Amaryllis.”  Those large, almost dinner plate-sized flowers are actually the genus Hippeastrum. The true Amaryllis, depicted here, is a fall-blooming plant. Though its growth habit is similar to Hippeastrum, it can be grown outdoors in the Pacific Northwest

Native to South Africa, they thrive in Mediterranean type  climates with full sun and well drained soil and are best left undisturbed once planted as they can take several years to flower from bulbs that are regularly available for planting in the spring.

 

 

Family: AMARYLLIDACEAE
Genus: Amaryllis
species: belladonna
Common Name:  Naked Ladies
Location: McVay Courtyard
Origin: South Africa
Height and Spread: 15-18″ tall stems and forms clumps 3-5ft. in width over time
Bloom Time: August-October

IMG_7145

IMG_7260

 

 

 

 

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Annual United Way “Day of Caring” made a huge impact at the Washington Park Arboretum

September 30th, 2014 by UWBG Communication Staff
photo

United Way Day of Caring volunteers. Photo courtesy of the Arboretum Foundation.

Over 100 volunteers teamed up on September 19th on six projects that included spreading 218 yards of mulch, salvaging 150 sword ferns and grubbing out truckloads of invasive blackberry. Thank you to every one involved in the Day of Caring!

2014 United Way Day of Caring Debrief
Sept 19, 2014 9a-1p

Participating partners:

Arboretum Foundation – volunteer recruitment and organizer

UW Botanic Gardens – project management (5 projects), equipment and supplies

Seattle Parks and Recreation (1 project), equipment and supplies

 

UWBG Projects Details:

    • Pacific Connections Garden-New Zealand Forest
      • Led by Kathleen DeMaria and Annie Bilotta
      • 80 yards of mulch spread. 30% of NZ forest
      • Participating corporation – Blucora. Approx 25 volunteers
photo

Volunteers make short work of a mountain of mulch in the Native Knoll.

  • Fern Salvage in Arboretum Loop Trail footprint S. end slope beyond Chilean Gateway
    • Led by Chris Watson and Preston Pew
    • 150 sword ferns dug up and transported to old lath house bed behind greenhouse
    • Participating corporation – Amazon. Approx 20 vols
    • Volunteerss win the “the most challenging” project award due to steep slope and hard ground
  • Native Knoll
    • Led by Roy Farrow and Neal Bonham
    • 60 yards of mulch moved and spread; 15 sword ferns planted
    • Participating corp – Nordstrom. Approx 20 vols. Plus 5 from Native Plant Study Group (Arboretum Foundation volunteers – led by Rita Cloney)
  • Hollies
    • Led by Ryan Garrison and Darrin Hedberg
    • 75 yards of mulch moved and spread covering the 3 Eurasian clade berms ; other 4 berms weeded
    • Participating corp – Virginia Mason. Approx 25 volunteers. And, 1 vol from CenturyLink Pioneers
      photo

      The Hollies collection looking a little scrappy before the volunteers arrived.

      photo

      The Hollies collections after the volunteers swarmed the area with barrow loads of mulch.

  • PCG-Chilean Gateway and Siskiyou Slope
    • Led by Kyle Henegar and Rhonda Bush (AF – Steward Coordinator)
    • 3 yards of mulch spread in Chilean Gateway; 3 yards of blackberry removed in Siskiyou Slope
    • Participating corp – Urban Renaissance Group. Approx 25 volunteers. Plus 8 Pacific Connections Garden Stewards
  • City Parks Project – west end of waterfront trail (former MOHAI side)
    • Led by Paul Smith and Giles Moorish
    • Moved and spread mulch
    • Participating corps N/A # of volunteers N/A
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Up By Roots: Healthy Soils and Trees in the Built Environment

September 30th, 2014 by Sasha McGuire, Education Program Assistant

Up by RootsUW Botanic Gardens: Up by Roots - Healthy Soils and Trees in the Built Environment is a one-day workshop on October 15 that highlights the principles of soil science and their use in facilitating the growth of healthy trees and developing water efficient landscapes. Healthy soils absorb and hold water and nutrients needed to grow long-lived trees. These same soils retain runoff and preserve water at the site, reducing the need for irrigation and limiting potential impacts on nearby water sources.

This is a hands-on workshop that includes lectures and field work intended to introduce the underlying scientific principles guiding tree biology and soil-water relations. It is only through a healthy respect of these guiding principles, that one can effectively design, install, and manage soils and trees in the urban landscape.

James Urban, FASLA, ISA is a landscape architect with over 30 years of experience in the field of urban development. This workshop combines Jim Urban’s extensive experience with contributions from local experts to address regulations and conditions specific to our area.

Presentations will be relevant to urban foresters, landscape professionals, consulting arborists, tree care professionals, urban planners, landscape designers, sustainability professionals, landscape architects, municipal managers, land managers, and planners.

LA CES PDH, CPH, ecoPRO, ASCA, APLD, PLANET, ISA credits available.

WHEN: October 15th, 8:15am-4:30pm
WHERE: UW Botanic Gardens – Center for Urban Horticulture, NHS Hall

 

Resources for Workshop Attendees

Introduction

Session 1: Soil Science

Session 2: Tree Biology and Urban Soils

Session 3: Field walk – Soil Assessment

Session 4: Practical Soil Applications

Additional Resources

 

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A glimpse into the past – Lookout rockery renovations

September 30th, 2014 by UWBG Communication Staff

By John A. Wott, Director Emeritus

One of the most interesting rockeries in the Washington Park Arboretum is located just below and north of the now restored Lookout.  It is an impressive wall of granite stones which gives great strength to the area on the southern edge of the large pond near the southern boundaries of Azalea Way. The original work was done by the Works Progress Administration laborers who defined many features within the Arboretum.

It would appear that it was neglected for much of its early life, and these photographs document its state in 1967. Taken by Brian O. Mulligan, then Director, the photos show the over-growth of grasses and other trashy plants. They were taken on July 2, 1967, and marked as the “north bank of Lookout, before reconstruction”.

lookout photo

For the next nearly 50 years, this has been a formidable rockery, with several prominent rhododendrons and other plants clinging to it. With the renovation of the Lookout, the plants at the top ridge have been removed, so again one can see north to the University District. The rockery is very steep and rugged for visitors to climb, even though many brave “souls” do.

Currently the UWBG staff is working on a renovation plan and they have been clearing much of the overgrown vegetation. Several new rhododendrons have been planted in honor of Professor Ben Hall and his wife Margaret, for his life-time research on rhododendrons.  So as you walk around this beautiful “bowl” at the south end of Azalea Way, watch for the rockery to again be a prominent feature in this section of the Arboretum.


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September Color Appears at the Washington Park Arboretum (Part II)

September 28th, 2014 by UWBG Horticulturist
Selected cuttings from the Washington Park Arboretum (September 22 - October 6, 2014)

Selected cuttings from the Washington Park Arboretum (September 22 – October 6, 2014)

1)    Alnus glutinosa ssp. betuloides
Birch-leaved Alder

  • Native to the mountains of eastern Turkey.
  • Listed as a threatened species by the International Union for Conservation of Nature.
  • Autumn brings pendulous male catkins and the mature female cones.

 

2)   Catalpa x erubescens        Indian Bean Tree

  • Uncommon tree with fetching, large, chocolate-purple young leaves that turn green.
  • Late summer brings masses of creamy white flowers flecked with yellow.
  • Hanging seed pods appear and remain long after the leaves have dropped.

3)   Pterocarya rhoifolia        Japanese Wingnut

  • The Wingnuts belong to the Walnut (Juglandaceae) family.
  • The amount of edible nut is comparable to that of the Scots Pine, i.e. not much.
  • The hanging decorative catkins give the tree a distinctive appearance in late summer.

4)   Styrax obassia        Fragrant Snowbell

  • This tree produces 6-8 inch fragrant white bell shaped flowers May to June.
  • Native to Hokkaido Island of Japan.
  • The tiny green seed pods hang like ornaments well into late summer/fall.

5)   X Sycoparrotia semidecidua        Chinese Fig Hazel

  • An inter-generic cross between two species – Parrotia persica and Sycopsis sinensis.
  • The flowers are unique, inconspicuous and easy to overlook.
  • The seed pods are beautiful ocher-colored, three dimensional stars.
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Washington Park Arboretum Soil is More Than Dirt

September 26th, 2014 by Kathleen DeMaria, Arboretum Gardener

This past April the Camellia area of the Washington Park Arboretum was paid a scientific visit by UW SEFS professor Dr. Darlene Zabowski and students from her Advanced Soil Genesis and Classification course (SEFS 513). Their goal was to learn how to excavate a soil pit and mine the walls for information about the history of the site, the current state of the soil and potential issues that may need mitigation. The site was chosen by David Zuckerman, Supervisor of Horticulture, as our Camellia collection is in need of a renovation, and he’s a strong proponent of soil analysis prior to any work being done in an area.

As with any good assessment, photos of the site were taken prior to any disturbance:

Camellias before dig

 

This site is located in the south end of the Arboretum just north of the gravel path leading to the newly refurbished lookout in the New Zealand garden. After the leaf litter and duff were cleared, the students started digging, and digging until a 3 foot deep pit was completed (notice the clear separation of ‘horizons’, or layers of soil):

Soil Pit2

In this area 3 feet was needed to ensure that the students got down to the ‘parent material’, or the underlying geological material in which soil horizons form. Soils inherit structure and minerals from their parent material through processes of physical or chemical weathering. This parent material remains the basis of the soil structure as other factors contribute to the soil’s texture (e.g. compaction, amendments, tillage).  According to Dr. Zabowski and her students, our Camellia soil has a parent material in the ‘Alderwood series’, and it shows evidence of compaction and large quantities of amended materials in the upper horizon. There was charcoal found in the middle/upper horizons indicative of a fire in the area (perhaps post-logging) or the charcoal could have come in with amendments added to the soil years ago. The parent material is glacial, composed mostly of ablation till and basal till and the years of amending and alteration can be seen even down into these lower horizons.

Soils layed out

As each horizon was unearthed, Dr. Zabowski (pictured above) had her students lay out a sample of the soil in ascending order to show and feel the difference from one layer to the next. The students were then charged with the task of coding out these samples by color using Munsell Soil Color Charts flip book. Soil color indicates the makeup of the soil within a given geographic area, which can influence the land’s fitness for usage. Samples of each horizon were also brought back to the lab and analyzed for chemical composition, bulk density, base saturation, and Cation exchange capacity (CEC). The Camellia soil was found to have a pH in the slightly acidic region (5.7-6.3), which is good for Camellias, as they like slightly acidic soil. The upper horizons of the soil were found to contain high levels of Ca, suggesting that there had been some CaCO3 added to the soil in the past (the high pH was also indicative of amending with CaCO3). The CEC of the soil was very high in the upper horizons, but this was to be expected at CEC is a measure of the soil’s fertility and nutrient retention capacity and this soil had been amended with organic matter for decades before this assessment (organic matter can have up to 3x the CEC of clay). The bulk density of the soil in the upper horizons suggests that there has been some compaction (likely due to foot traffic as there is a bench near the site) and that remediation of this density should accompany any work done in this area.

The UWBG horticulture staff welcomes and encourages university use of the arboretum for educational purposes as we curate and maintain 230 acres of urban forest as short walk from main campus. Got an idea for research in the arboretum? Contact David Zuckerman at dzman@uw.edu to get your shovels into our soil!

 


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Fruits & Nuts appear in autumn

September 23rd, 2014 by Catherine Nelson, Adult Tours Program Assistant

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