January 11th, 2015 by Kathleen DeMaria, Arboretum Gardener
Selected cuttings from the Washington Park Arboretum (January 5 – 18, 2015)
“Piercing, sucking and galling!”
1) Mites (on Sasa Bamboo and Skimmia)
- Stippling and yellowing of leaves are often indicative of the presence of mites.
- Feed by piercing underside of leaves and sucking chlorophyll out decreasing photosynthesis, reducing plant vigor and compromising the appearance.
- Mites are not insects; they are arachnids.
2) Galls (on Willow and Rose)
- Abnormal plant growths caused by various organisms (insects, mites, fungi, etc.)
- Galls are formed by increased production of normal plant hormones as response to feeding, egg-laying or disease infiltration and are often not harmful to the plant.
- Galls can be on leaves, stems, twigs, buds, flowers and roots
3) Blights (on Hazelnut and Cherry)
- Refers to a symptom affecting plants in response to infection by a pathogen.
- Blights come on rapidly and can cause complete chlorosis and browning of plant tissues such as leaves, branches and twigs; plant death is not uncommon.
- Aided by cool, moist conditions and limited air flow to plants…perfect for the Pacific Northwest!
4) Phylloxera (on Oak)
- Microscopic, yellow sucking aphid relatives that feed on leaves and buds.
- Yellowish spots on leaves in spring turn to brown by summer and defoliate.
- Repeated defoliation abates photosynthesis and can lead to plant death.
5) Armillaria root rots (shown on Bigleaf Maple, but many trees are susceptible)
- Fungus cause stunted leaves, chlorotic needles, dieback of twigs and branches and eventually death.
- Identified by white mats of fungal mycelium between the inner bark and wood and honey-brown mushrooms growing on or around the base of the tree.
- A big threat to the lumber industry as the wood is unsalvageable.
November 29th, 2014 by UWBG Horticulturist
Selected cuttings from the Washington Park Arboretum (November 24 – December 7, 2014)
1) Araucaria araucana (Monkey Puzzle)
- Native to Chile, no other conifer quite like it!
- Seeds are used to make an alcoholic ceremonial drink called mudai.
2) Picea glauca (White Spruce)
- Native to northern temperate forests of North America.
- Captain Cook made a spruce beer, possibly curing his crew from scurvy.
3) Pinus cembra (Swiss Stone Pine)
- Native to Alps of Central Europe.
- Try a Royal Tannenbaum cocktail made with Zirbenz Stone Pine liqueur!
4) Pseudotsuga menziesii (Douglas Fir)
- Native to our “neck of the woods”.
- McCarthy’s Clear Creek Distillery (in Portland OR) makes a green spirit from Douglas Fir buds called Douglas Fir eau-de-vie.
5) Taiwania cryptomerioides (Coffin Tree)
- Native to eastern Asia.
- Imbibe too much and you may wind up in a box made from this tree.
* All references to alcoholic drinks are from the book, The Drunken Botanist
by Amy Stewart, ©2013, Algonquin Books of Chapel Hill.
NOTE: Use our interactive on-line map for location and other information on the above
[Enter Latin name in search box in the upper right corner.]
November 10th, 2014 by UWBG Horticulturist
Selected cuttings from the Washington Park Arboretum (November 3 – 16, 2014)
1) Callicarpa bodinieri var. giraldii ‘Profusion’ (Beautyberry)
- Native to western China.
- Ornamental purple berries on display in autumn months.
- Specimen located north of the Wilcox Bridge by the parking lot.
2) Gaultheria mucronata ‘Rubra’
- Native to southern Chile.
- Formerly known as Pernettya, this particular variety has carmine pink berries.
- Specimen is located in the Chilean Gateway Garden.
3) Grevillea victoriae ‘Marshall Olbricht’
- Native to Australia. This cultivar is from a seedling, possibly a hybrid, named for the co-founder of Western Hills Nursery in California.
- Exotic orange flowers persist throughout winter – loved by hummingbirds.
- Specimen located in the Australian entry garden at Pacific Connections.
4) Quercus cerris (Turkey Oak)
- Native to southern Europe.
- Notable for hairy caps on the acorns. Trunk can reach six feet in diameter.
- Specimen located in the Viburnum Collection near Lake Washington Boulevard.
5) Wollemia nobilis (Wollemi Pine)
- Not a pine, but a member of Araucaceae, the family of the Monkey Puzzle Tree.
- Wollemia was known only from fossil records until it was discovered in Australia’s Wollemi National Park in 1994 by David Noble, hence its name.
- Our specimen is growing at the bus turnaround on Arboretum Drive.
October 27th, 2014 by UWBG Arborist, Chris Watson
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.
October 10th, 2014 by UWBG Horticulturist
Selected cuttings from the Washington Park Arboretum (10/6/14-10/19/14)
1) Franklinia alatamaha
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
- 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.
September 28th, 2014 by UWBG Horticulturist
Selected cuttings from the Washington Park Arboretum (September 22 – October 6, 2014)
1) Alnus glutinosa ssp. betuloides
- 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.
September 14th, 2014 by UWBG Horticulturist
The State of the Arboretum
Selected cuttings from the Washington Park Arboretum (September 8 – 21, 2014)
1) Liriodendron tulipifera Tulip Tree
- The state tree of Indiana.
- The Western Hemisphere representative of the two-species genus Liriodendron, and the tallest eastern hardwood.
2) Pinus resinosa Red Pine
- The state tree of Minnesota.
- It is a long-lived tree, reaching a maximum age of about 500 years.
- The wood is commercially valuable in forestry for timber and paper pulp, and the tree is also used for landscaping.
3) Pinus strobus Eastern White Pine
- The state tree of Michigan.
- Eastern white pine forests originally covered much of northeastern North America. Only one percent of the old-growth forests remain after the extensive logging operations that existed from the 18th century into the early 20th century.
- This tree is known to the Native American Haudenosaunee (Iroquois Nation) as the “Tree of Peace”.
4) Sequoia sempervirens Coast Redwood
- The state tree of California.
- These trees are among the oldest living things on Earth.
- Before commercial logging and clearing began by the 1850s, this massive tree occurred along much of coastal California and the southwestern corner of coastal Oregon.
5) Tsuga hetrophylla Western Hemlock
- The state tree of Washington.
- Tsuga heterophylla is an integral component of Pacific Northwest forests west of the Coast Ranges, where it is a climax species. It is also an important timber tree throughout the region, along with many of its large coniferous associates.
August 17th, 2014 by Kathleen DeMaria, Arboretum Gardener
Selected cuttings from the Washington Park Arboretum (August 11 – 24, 2014)
1) Poliothyrsis sinensis
- A rare and very attractive small flowering tree of upright, open habit.
- Originally brought from China to the Arnold Arboretum by E.H. Wilson.
- Big 6-8” mildly fragrant, creamy flower clusters (corymbose panicles) make a significant contribution to the August-September garden.
- Located in grid 30-3E, near the south entrance to the Woodland Garden along Arboretum Drive.
2) Daphniphyllum macropodum
- This dioecious plant (translation = “of two houses”) needs plants of both sexes to seed.
- Our largest grouping sits in grid 7-2E. This area was recently renovated for the New Zealand Garden construction, allowing more light and air to these plants.
- Purplish-red petioles, copious berries and leaves arranged in tight spirals make this one of the most asked-about plants in the Washington Park Arboretum.
3) Veronica salicifolia (Hebe salicifolia)
- Is it a Hebe? Is it a Veronica? Just wait and it might change again!
- Large, spear-shaped, white flowers populate this New Zealand native in late summer.
- Salicifolia = “leaf like a Salix (willow)”, hence the common name willow-leaved hebe.
4) Buplerum fruitcosum
- This evergreen shrub in the carrot family has striking leathery blue-green foliage.
- Long-lasting, umbels of greenish-yellow flowers bloom in late spring/early summer.
- Flowers are highly attractive to a number of predatory insects that feed on aphids and other garden pests.
5) Argyrocytisus battandieri
- Commonly called Pineapple Broom, this pea-family plant produces yellow flowers atop blue-gray foliage.
- Native to Morocco, this plant grows best in full sun and well-drained soil.
- Located along the west side of Arboretum Drive in grid 16-5E.
August 4th, 2014 by UWBG Arborist, Chris Watson
Selected cuttings from the Washington Park Arboretum (July 21 – August 8, 2014)
1) Houpu Magnolia (Magnolia officinalis var. biloba)
- Unique bi-lobed leaf 8-12″ in length
- 4-8″ seed pods on display in late summer
- Located in grid 27-1W in the Rhododendron hybrid bed
2) Sargent Magnolia (Magnolia sargentiana var. robusta)
- Bears large pink flowers in spring
- Large, pinkish-red fruit appear in late summer and fall
- Located in grid 13-7E in Rhododendron Glen
3) Rehder Tree (Rehderodendron macrocarpum)
- White flowers appear in spring
- 3-4″ seed pods weigh down branches in late summer
- Located in grid 13-6E and elsewhere throughout the Washington Park Arboretum
4) Himalayan Stachyurus (Stachyurus himilaicus)
- Deciduous or semi-evergreen shrub to height of 10’
- Displays clusters of flowers in early spring
- Located in grid 25-1W
5) Yunnan Stachyurus (Stachyurus yunnanensis)
- Small evergreen shrub to height of 6’
- Chains of white flowers appear in spring
- Located in grid 25-1W
July 12th, 2014 by UWBG Horticulturist
Selected cuttings from the Washington Park Arboretum (July 7 – 20, 2014)
1) White Ash (Fraxinus americana)
- Tough, plentiful, and easily bent into curves, Ash is used in tennis racquets, billiard cues, skis, and baseball bats.
- White Ash is native to eastern and central North America.
- This cutting is from the cultivar ‘Rose Hill’, located in grid 47-3E near the Lagoons.
2) Common Box (Buxus sempervirens)
- Used for crocquet balls because of its hardness.
- Native to Europe, northern Africa and western Asia.
- The cultivar here is ‘Argentea’ from grid 5-B in our Boxwood Collection.
3) American Hop Hornbeam (Ostrya virginiana)
- The first ice hockey sticks were made from the dense wood of this small tree in the mid-19th century until the 1930s by the Mi’kmaq people of Nova Scotia.
- Ostrya virginiana is native to eastern North America.
- The Arboretum has two trees in grids 19-3W and 24-4W.
Close-up photo of Persimmon flowers
4) Persimmon (Diospyros virginiana)
- The “woods” of golf (drivers, not Tiger’s) were typically made from this American member of the ebony family from which it inherits its extreme density.
- Persimmon is most common in the southeastern United States.
- In the Arboretum, they are in grids 12-1W and 12-2W, north of the Boyer Street parking lot.
5) Sugar Maple (Acer saccharum)
- Commonly called “rock” maple by those who value its hardness and smooth grain.
- This native of eastern North America provides wood for bowling alleys, bowling pins, basketball courts, and baseball bats.
- The Arboretum has several cultivars in various locations.