June 15th, 2014 by UWBG Horticulturist
1) Hydrangea macrophylla ‘Madame Emile Mouillere’
- A blizzard white beauty all summer, long considered the best white mop head.
- A charming companion to evergreen shrubs.
- A beautiful 70-year old specimen graces the Hydrangea Collection along the Arboretum Drive.
2) Leucothoe davisiae (Sierra Laurel)
- Native to the mountains of northern California and southern Oregon.
- One of 4,000 species in the Ericaceae family.
- A 20-year old specimen can be found in the Rhododendron Glen.
3) Rosa moschata ‘Plena’ (Double Musk Rose)
- Cultivated in European and American gardens for centuries.
- Grown for its strong, clove musk fragrance and abundant alabaster white flowers.
- A 65-year old specimen is flourishing by the entrance to the horticulture headquarters.
4) Stewartia pseudocamellia var. koreana (Korean Stewartia)
- Native to Japan and Korea, this tree has garnered the Royal Horticulture Society’s Award of Garden Merit.
- The flowers are white with orange anthers, shaped like those of the related camellia.
- A graceful 64-year old specimen is growing beautifully at the south end of Arboretum Drive.
5) Philadelphus lewisii (Lewis’ Mock Orange)
May 29th, 2014 by UWBG Horticulturist
Selected cuttings from the Washington Park Arboretum (May 27 – June 8, 2014)
1) Crataegus crus-galli Cockspur Hawthorn
- Native to eastern North America, this small deciduous tree has a pleasant habit and is now showing off its small white flowers, but don’t get too close! The rigid thorns can be up to three inches long.
- Hawthorns are classified within the plant family Rosaceae, and are allied to Cotoneaster, Mespilus, and Pyracantha.
- This specimen is located on the east side of Lake Washington Boulevard, just north of the Boyer Parking Lot.
2) Deutzia x hybrida ‘Magicien’
- Named after Johann van der Deutz, a friend of Thunberg in 18th century Amsterdam, Deutzia contains some of the most beautiful shrubs currently in flower. It is a member of the family Hydrangeaceae.
- This specimen is located near the east side of our field nursery, along the Broadmoor fence.
3) Kalmia latifolia Mountain Laurel
- Native to eastern North America, Kalmias are a small group of shrubs within the family Ericaceae. They were named by Linnaeus in honor of Peter Kalm, one of his pupils. The Arnold Arboretum near Boston boasts a great hedge of K. latifolia that are over 200 yards long.
- These cuttings were taken from specimens on Arboretum Drive near the Woodland Garden.
4) Ostrya carpinifolia European Hop Hornbeam
- A member of the family Betulaceae, the genus Ostrya contains about ten closely related species native to various parts of the northern hemisphere. O. carpinifolia is native to southern Europe. Female catkins develop into hop-like fruits in the summer.
- This specimen is located within our Hornbeam Collection near the terminus of Foster Island Road.
5) Viburnum dilatatum Linden Viburnum
- An upright, deciduous shrub native to Japan and China, V. dilatatum is displaying its small flowers borne in domed, terminal corymbs, similar to those of ‘lacecap’ hydrangeas.
- This cutting was taken from a specimen within our Viburnum Collection, just west of the “True Ashes”.
May 18th, 2014 by UWBG Horticulturist
Selected cuttings from the Washington Park Arboretum (May 12 – May 25, 2014)
“That’s Ancient History”
1) Cedrus libani (Cedar of Lebanon)
- The Cedar of Lebanon has been prized for its high quality timber, oils and resins for thousands of years.
- It was used by the Phoenicians and Egyptians and was mentioned in the Epic of Gilgamesh.
- Because of its significance, the word “cedar” is mentioned 75 times in the Bible, and played a pivotal role in the cementing of the Phoenician-Hebrew relationship.
2) Helleborus niger (Black Hellebore, Christmas Rose)
- Helleborus niger is commonly called the Christmas rose due to an old legend that it sprouted in the snow from the tears of a young girl who had no gift to give the Christ child in Bethlehem.
- During the Siege of Kirrha in 585 B.C., Hellebore was reportedly used by the Greek besiegers to poison the city’s water supply. The defenders were subsequently so weakened by diarrhea that they were unable to defend the city from assault.
3) Laurus nobilis (Bay Laurel, Sweet Bay)
- Bay Laurel was used to fashion the laurel wreath of ancient Greece, a symbol of highest status. A wreath of bay laurels was given as the prize at the Pythian Games because the games were in honor of Apollo, and the Laurel was one of his symbols.
- In the Bible, the Laurel is often an emblem of prosperity and fame. In Christian tradition, it symbolizes the resurrection of Christ.
4) Rhododendron ponticum
- Xenophon described the odd behavior of Greek soldiers after having consumed honey in a village surrounded by Rhododendron ponticum during the March of the Ten Thousand in 401 B.C.
- Pompey’s soldiers reportedly suffered lethal casualties following the consumption of honey made from rhododendron deliberately left behind by Pontic forces in 67 B.C. during the Third Mithridatic War. Later, it was recognized that honey resulting from these plants has a slightly hallucinogenic and laxative effect.
5) Taxus baccata (English or European Yew)
- One of the world’s oldest surviving wooden artifacts is a Clactonian yew spear head, found in 1911 in Essex, U.K. It is estimated to be about 450,000 years old.
- A passage by Caesar narrates that Catuvolcus, chief of the Eburones poisoned himself with yew rather than submit to Rome (Gallic Wars 6:31).
May 3rd, 2014 by UWBG Horticulturist
Selected cuttings from the Washington Park Arboretum (April 28 – May 11, 2014)
1) Rhododendron spp. Azalea
- Azaleas are in the genus Rhododendron, with evergreen azaleas in the subgenus Tsutsusi and deciduous azaleas in the subgenus Pentanthera.
- The Olmstead Brothers originally planned for 11,000 azaleas to be planted along Azalea Way. More than 3,100 have been planted and over 2,000 remain.
- Azalea Way contains 21 species of azalea and more than 200 hybrids.
2) Tsuga heterophylla Western Hemlock
- Our native western hemlocks are currently laden with new female cones which are deep purple when immature.
- Currently, a scientific experiment is being conducted as a collaboration between the Washington Park Arboretum and the University of Massachusetts, using the collection of T. heterophylla and T. canadensis.
- We are studying the predator/prey relationships among the hemlock Wooly Adelgid, eastern and western hemlocks, and the predator species that prey on the Adelgid.
3) Syringa oblata var. dilatata, S. patula Lilac
Close-up photo of newly-forming female cone on Larix decidua
- Our Lilac Collection contains more than 14 species along with several more hybrids.
- Our primary lilac display is on Azalea Way, just south of the Woodland Garden.
4) Larix decidua, L. kaempferi Larch
- Now is a great time to admire many conifers for their display of young and old cones on the same branch.
5) Rhododendron ‘El Camino’ Halfdan Lem hybrid
- Our Puget Sound Rhododendron hybrid bed is located on Azalea Way south of our Lilac Collection.
- This bed contains plants from local hybridizers dating back to the early 1940s.
April 20th, 2014 by UWBG Horticulturist
Selected cuttings from the Washington Park Arboretum (April 15 – 28, 2014)
1) Melicytus angustifolius
- This southern hemisphere Violaceae relative thrives in rocky places in mountains or on coasts, or in evergreen forests.
- Is ‘dioecious’ or ‘of two houses’ in Greek translation; male and female flowers are present on separate plants.
2) Erica arborea var. alpina
- Found along the southern end of Arboretum Drive, this is one of the older collections in the Washington Park Arboretum, dating back to 1947.
- This form, var. alpina, is a smaller shrub, very hardy, and with brighter green foliage, making an imposing highlight among smaller heaths and heathers.
3) Poncirus trifoliata (syn. Citrus trifoliata)
- Bitter, non-edible yellow fruits that resemble a small orange
- Two large specimens in the Arboretum found in grid 8-1W and 12-B, north of the large parking lot off of Lake Washington Bouvelard.
4) Viburnum carlesii var. bitchiuense
- This spicy smelling Viburnum is the intoxicating fragrance you’ll be hit with the moment you walk out the front door of the Graham Visitor’s Center.
- Listed on the IUCN Red List of Threatened Plants in 1997, our cultivation of this plant helps to preserve a propagation source for future plants.
5) Phyllocladus alpinus
- This New Zealand conifer can photosynthesize through highly modified, leaf-like shoots called phylloclades as well as through leaves.
- The newly-formed seed cones are berry-like, with a fleshy white aril.
- Male and female flowers are separate, but borne on the same plant.
April 6th, 2014 by UWBG Horticulturist
Selected cuttings from the Washington Park Arboretum (4/1/14 – 4/14/14)
1) Berberis x lologensis
- A natural hybrid of B. darwinii and B. linearifolia originally found near Lake Lolog, Argentina in 1927
- If you can get past the thorns, enjoy the rich, spicy fragrance.
- Located in grid 14-6E near Arboretum Drive.
2) Acer tegmentosum ‘Joe Witt’
- This striped-bark maple is named for former Arboretum Director Joseph Witt.
- Located in the Witt Winter Garden and on Arboretum Drive in the Peonies.
3) Magnolia salicifolia ‘Else Frye’
- Selected by Joe Witt for its larger flowers and named for the wife of T.C. Frye.
- See Arboretum Bulletin Summer 1961, Summer 1962, and Winter 1962 for articles about this tree and the Fryes.
- The original tree is in the Magnolia Collection, grid 26-2E.
4) Magnolia x kewensis ‘Wada’s Memory’
- Part of a collection of plants purchased from Koichiro Wada in Japan in 1940.
- Selected by Arboretum Director Brian Mulligan for its unusually large flowers.
- The original tree is in grid 11-6E in the Hydrangeas.
5) Quercus suber (Cork Oak)”
Close-up photo of Quercus suber (Cork Oak)
- Evergreen oak native to southern Europe. A tree of incalculable social value, it produces the cork of
- Located in the Rock Roses on Arboretum Drive.
- This cutting includes the distinctive acorns – extremely rare in the Pacific Northwest.
March 21st, 2014 by UWBG Horticulturist
Selected cuttings from the Washington Park Arboretum (March 17 – 30, 2014)
1) Acer rubrum (Red Maple)
- Specific epithet, rubrum (red), refers to foliage in fall; however, flowers are red too
- One of the earliest trees to flower, appearing in March, well before the leaves
- Located at south end of Arboretum Drive East, against the Broadmoor fence
Close-up photo of the Acer rubrum (Red Maple) flowers
2) Camellia japonica ‘Jupiter’
- Carmine-red flowers with prominent yellow stamens on white filaments
- Located along Ridgetop Trail at head of Rhododendron Glen
3) Chaenomeles sp. (Flowering Quince)
- Old-fashioned, early spring flowering shrub
- OK, so this specimen is not the reddest available, but the best I could find.
- Located behind the Stone Cottage along the public path
4) Grevillea victoriae (Mountain Grevillea)
- This proteaceous plant’s foliage was the feature cutting for the first half of March 2014; now it’s the red flowers.
- Located in the Pacific Connections – Australia Entry Garden
5) Rhododendron strigillosum
- Early maroon-red flowering rhododendron
- Twigs and leaf stalks on young growth covered with long bristles
- Specimens located in the Witt Winter Garden, Woodland Garden and Sino-Himalayan Hillside
March 9th, 2014 by Pat Chinn-Sloan
Selected cuttings from the Washington Park Arboretum (March 3 – 16, 2014)
1) Berberis fortunei (Chinese Mahonia)
- Previously categorized in the genus, Mahonia
- Characterized by narrow, serrated evergreen leaves
- Located in the Sino-Himalayan hillside
2) Grevillea victoriae (Mountain Grevillea)
- Australian shrub, growing up to four meters
- Named for Queen Victoria
- Located in the Pacific Connections – Australia Entry Garden
3) Lomatia myricoides (River Lomatia)
- Originally placed in the genus, Embothrium
- Specific epithet refers to foliage similar to the genus, Myrica
- Located near the Pacific Connections – New Zealand Forest
4) Morella californica (California Bayberry)
- Formerly of the genus, Myrica
- A Pacific Coast native shrub that is well suited for borders and hedges
- Located in the Pacific Connections – Cascadia Entry Garden
5) Podocarpus macrophyllus (Kusamaki)
- Japanese conifer, sometimes referred to as Buddhist Pine
- Known by carpenters for termite resistant wood
- Located near the junction of the Middle Trail and Lower Trail
February 23rd, 2014 by Pat Chinn-Sloan
1) Acer monspessulanum var. turcomanicum
Selected cuttings from the Washington Park Arboretum (February 17 – March 2, 2014)
- An elegant, compact tree reaching 23-33 feet tall.
- Suitable for warm climates and adapted to calcareous and stony soils.
- A mature individual is growing in the Mediterranean bed along Arboretum Drive.
2) Magnolia kobus Kobushi Magnolia
- Blooms in early spring and bears pleasantly fragrant white flowers.
- Native to Japan and cultivated in temperate climates.
- A lovely, large specimen sits in the Arboretum Magnolia Collection.
3) Rhodondendron ‘Directeur Moerlands’
Azalea ‘Directeur Moerlands’
- Derived from crosses between Japanese azaleas and Chinese azaleas.
- Known for their excellent fall color and unsurpassed springs flowers.
- Azalea Way is loaded with beautiful azaleas just ready to explode for spring.
4) Ribes sanguineum ‘Henry Henneman’ Henry Henneman Winter Currant
- Studded with a cap-burst of color at a botanically bereft time of year.
- Easy to grow, well-mannered and amenable to pruning.
- The Cascadian Entry Garden boast several cultivars of this wonderful, early blooming shrub.
5) Sambucus racemosa Red Elderberry
- Grows in riparian environments, woodlands and in generally moist areas.
- Many parts of the plant are poisonous and have been used as an emetic.
- Native to the Pacific Northwest, elderberry bushes dot the Arboretum. Birds love the seeds.
February 6th, 2014 by Pat Chinn-Sloan
Selected cuttings from the Washington Park Arboretum (February 3 – 16, 2014)
1) Chimonanthus praecox Wintersweet
- With exceedingly fragrant yellow flowers borne on the bare shoots in winter, C. praecox has a suitable home here within the Witt Winter Garden.
- Chimonanthus is the Chinese counterpart of the North American genus, Calycanthus.
2) Lonicera standishii Winter Honeysuckle
- A native of China, L. standishii is a perennial favorite because of its charming fragrance.
- This specimen can be found in the Witt Winter Garden.
3) Pieris japonica ‘Valentine’s Day’
- Known commonly as ‘Lily of the Valley’, P. japonica is an evergreen shrub of low habit. The clustered panicles of this particular cultivar are a dark, dusky red color, giving it plenty of mid-winter attraction.
- Located near the south end of the Lilac Collection along Azalea Way.
4) Prunus x subhirtella ‘Rosea’
- Native to Japan, this relatively small flowering cherry has begun to show us its rose-pink blossoms.
- Several specimens can be found throughout the Arboretum, including one along the trail that leads from here to the Winter Garden.
5) Viburnum specimens
- V. farreri ‘Candidissimum’
- V. foetens
- V. x bodnantense ‘Deben’