January 25th, 2015 by UWBG Horticulturist
Witt Winter Garden
Selected cuttings from the Washington Park Arboretum (January 19-31, 2015)
1) Cornus sanguinea ‘Midwinter Fire’ Bloodtwig Dogwood
- Young stems of this cultivar are orange-yellow with the sunny side turning carmine red.
- Stem color of species is gray to purple, while the color of C.s. ‘Midwinter Fire’ is yellow-green in summer changing to winter colors rapidly at leaf drop in fall.
2) Hamamelis x intermedia ‘Pallida’ Witch Hazel
- This hybrid of H. japonica and H. mollis was selected for its pale sulfur-yellow flowers which tend to glow in the low light levels of morning and evening.
- Cultivars of witch hazel can have flower colors from pale yellow to deep red, some being quite fragrant while others are much less so.
3) Lonicera standishii Honeysuckle
- This semi-evergreen shrub bears fragrant flowers from early winter to early spring.
- Lonicera standishii is native to China.
4) Ruscus aculeatus Butcher’s Broom
- Lacking true leaves, what you are seeing are called “cladophylls” which are simply flattened stems.
- The flowers of this plant are dioecious, only 2 mm across and are located in the center of the cladophylls.
- Butcher’s Broom is native to Europe, Turkey, North Africa and the Azores.
5) Viburnum tinus ‘Pink Prelude’ Laurustinus
- This species has been cultivated in England since the 16th century.
- V.t. ‘Pink Prelude’ has white flowers that age to pink.
- The flowers of laurustinus are followed by small, but showy metallic-blue fruit.
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 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 20th, 2014 by UWBG Horticulturist
Arboretum Tree Removal Notification:
The week of 8/25/14, UWBG tree crew will embark on a project located in the Winter Garden (read about project below).
4 western red cedars will be removed due to negative impact to plant collections and garden encroachment.
All pedestrian path detours and other safety considerations will be handled by tree crew.
If possible, cedar logs will be salvaged for future park uses.
UW professor of landscape architecture and designer of our Winter Garden (1987), Iain Robertson, states it’s time to open up the “room” that has been closing in on the Winter Garden for over 25 years. Continuous growth of the “living walls”, predominantly western red cedars, is now negatively impacting many of the garden’s choice plant collections. Due to this encroachment, the garden “room” is feeling confining. Judicious consideration and deliberation has led to the following curation and horticultural decisions.
- Removal of 4 western red cedars to provide needed light and future growing space for plant collections. In all cases, the “room’s walls” will expand, yet filled in by existing trees in the background to continue to provide the experience of being in an enclosed space.Pruning of several other cedars to provide light and future growing space for plant collections.
- 2 on the west side in the “twig bed”
- 1 on the south side next to the Chinese red birch grove
- 1 on the east side growing over several camellias and other collections
August 8th, 2014 by UWBG Horticulturist
Does anyone reading this know where our arboretum’s “lost” Enkianthus grove is located? By “lost”, I mean extremely well-hidden under a dense canopy of western red cedars and other trees.
Enkianthus specimens previously “lost” in the overgrowth.
Enkianthus are shade-tolerant shrubs, but NOT “black-hole” shade tolerant. Like most living plants, they do need light to grow and thrive. It’s a bit embarrassing, but I can honestly say, during my 30 plus year tenure on the UWBG horticulture staff, I don’t recall ever working in the area for longer than maybe a day cleaning up after a storm or pruning a few of the bigger trees. And, we definitely did not pay any attention to the main attraction – a grove of over 50 Enkianthus specimens, mostly all E. campanulatus (red-vein enkianthus) and over 70 years old! Well, the answer to the question above is Rhododendron Glen, encompassing several grid maps (14-2E, 14-3E and 15-3E).
Accession number 2352-37, this Enkianthus campanulatus was planted in 1937.
Now for the good news. Thanks to funding designated for Rhododendron Glen, our horticulture staff has taken on the project to restore the grove for all to be able to once again, after a very long hiatus, enjoy its natural beauty and splendor throughout the year.
The project scope includes the following to improve the health and display of the Enkianthus grove:
- Increase light conditions through selective understory brush clearing, tree removals and pruning
- Open view corridors and a cleared natural pathway for visitors to walk from the upper Rhododendron Glen pond area down to the lower “Lookout” pond
- Improve health of the Enkianthus through practicing sound horticulture: mulching, watering and fertilizing the grove
For more information about the ornamental shrub, Enkianthus campanulatus, go to Wikipedia website below:
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.
June 29th, 2014 by UWBG Horticulturist
Selected cuttings from the Washington Park Arboretum (June 23 – July 6, 2014)
1) Erhetia dicksonii
Close up photo of Ehretia dicksonii inflorescence
- Ornamental tree from Asia with corky bark and fragrant white terminal cymes.
- Located along path heading up to Rhododendron Glen from Azalea Way, grid 15-1E.
- Go to link below for thorough description and uses.
2) Holodiscus discolor (Ocean Spray)
- My favorite summer flowering Pacific Northwest native deciduous shrub.
- In full flowering, cascading glory now throughout our native matrix.
3) Hypericum henryi ssp. uraloides
- The really big Azalea Way flower show may be over, but now it’s Hypericum time.
- This shrubby St. John’s wort is a huge attractant of many kinds of bees.
- Located in east-side bed J, midway down Azalea Way, grid 20-1W.
4) Illicium henryi (Henry Anise Tree)
Close up photo of Toona sinensis leaves and inflorescence
- A handsome evergreen woodland shrub or small tree from China.
- Waxy, bright rose-colored flowers. Leaves and star-shaped fruit give off a scent of anise when crushed.
- Located along forested Ridge Trail within the Asiatic Maple section, grid 25-1E.
5) Toona sinensis (Chinese Cedar)
- You can Toona piano, but you can’t Toona fish . . . or in this case, a tree.
- Deciduous tree from eastern and southeastern Asia with pinnately compound leaves and white flowering panicles in summer.
- Located in north Pinetum, grids 44 and 45-6W. For cultural, medicinal and commercial (timber) importance, go to link http://en.wikipedia.org/wiki/Toona_sinensis.