April 25th, 2016 by UWBG Horticulturist
The stories of people and plants are intricately intertwined. The plants of the University of Washington Botanic Gardens have many stories to tell, and here are just a few to wet your whistle. Explore our website at to look up and locate plants in the Arboretum and learn more of our stories.
1) Abies grandis – Grand Fir “Fir Above It All”
- This particular tree has witnessed the entire history of the Washington Park Arboretum. It is almost certainly a remnant of the vegetation that existed before the site was logged circa 1896. You can read more about this remarkable tree’s history on the March 2016 plant profile.
2) Castenea dentata – American Chestnut
“A Blight to Remember”
- Once upon a time in the eastern forests of North America, the mighty American Chestnut was a ubiquitous giant. This tree could shape entire ecosystems, providing food and shelter to all manner of beasts and men. It was said that the chestnuts would sometimes pile up so high you could scoop them up with a shovel. This fast-growing timber tree provided wood that could be used to make almost anything a carpenter can build. Sadly, this tree has been decimated by “chestnut blight”, a fungus that quickly girdles and kills the tree. The University of Washington Botanic Gardens is committed to the conservation of this tree and many other species that are threatened.
3) Rhododendron ‘Lem’s Cameo’ “Halfdan Lem and the Rhodies of War”
- Some of Halfdan Lem’s story was told to the Vancouver Rhododendron Society meeting of March 1993. When World War II started, Mr. Fred Rose in England sent Lem seed and scions of many of his crosses and the resulting plants formed the nucleus of Lem’s breeding program. By the mid-sixties, he had made over 2000 crosses and had about 50,000 seedlings. One of his first introductions was “Lem’s Cameo”, an outstanding and popular variety. Halfdan was reported to be quite a “colorful” character, and you can see some of his legacy in the Puget Sound Hybrid Garden. Many other stories about Halfdan Lem may be found in the Journal of the American Rhododendron Society, which is available online.
April 10th, 2016 by UWBG Horticulturist
Selected cuttings from the Washington Park Arboretum, April 4 – 17, 2016
1) Acer mandshuricum Manchurian Maple
- The Manchurian Maple is native from Eastern Siberia into China and strongly resembles Acer griseum and Acer triflorum.
- This species is located in the Asian Maples Collection.
2) Distylium racemosum Isu Tree
- The flowers of Distylium racemosum are petalless, but have attractive red calyces (whorl of sepals) and purple stamens.
- The Isu tree is native to southern Japan, but can be found in the Witt Winter Garden and in our Hamamelidaceae Collection, east of Arboretum Drive near the Pacific Connections gardens.
3) Pieris japonica Lily-of-the-Valley Shrub
- This shrub from eastern China, Taiwan and Japan begins the spring with showy terminal panicles of flowers that range from white to dark-red, followed by extremely colorful new growth which will fade to green in summertime.
- Lily-of-the-Valley can be found at the Graham Visitor Center, the Witt Winter Garden and Rhododendron Glen.
4) Rehderodendron macrocarpum
- This native of southwestern China and Vietnam is a member of the Styracaceae family and displays typical Styracaceous white pendent flowers in Spring.
- Though a relatively small tree in the Pacific Northwest, Rehderodendron macrocarpum is a dominant component in its native habitat.
- Specimens can be found along Azalea Way near our Puget Sound Rhododendron hybridizers bed as well as in the Witt Winter and Woodland Gardens.
5) Viburnum bitchuense Bitchiu Viburnum
- This native of Korea and Japan has pink buds that open to wonderfully fragrant white flowers.
- Viburnum bitchiuense can be found just across Arboretum Drive, outside the east doors of the Graham Visitor Center.
March 28th, 2016 by UWBG Horticulturist
Spring is not typically known for its subtlety around these parts, but upon its early awakening many plants warrant a closer look. Enjoy!
Selected cuttings from the Washington Park Arboretum,
March 21, 2016 – April 4, 2016
1) Acer palmatum ‘Katsura’ Katsura Maple
Close-up of Acer palmatum ‘Katsura’
- One of the first Japanese maples to leaf out each spring. The small, five-lobed leaves emerge pale yellow-orange, with brighter orange margins.
- Found in the semi-dwarf group of Japanese maples.
- Specimen 19-10*A is located in grid 30-4E.
2) Ginkgo biloba Maidenhair Tree
- Emerging leaves are “mini-mes” of the actual size.
- Also seen are emerging male cones.
- This sample is taken from the Graham Visitor Center specimen located in the northwestern corner of the parking lot.
3) Larix laricina Tamarack or Eastern Larch
- Deciduous conifer native to eastern North America
- Cutting sample shows newly emerging needles and last year’s cones.
- Specimen is located in grid 33-5W, Pinetum.
4) Photinia beauverdiana var. notabilis
- Rose family deciduous shrub from China
- Hairy, white newly-emerging leaves and flowers on cutting sample
- Specimen is located in grid 33-5W, Pinetum.
5) Ribes sp. (maybe R. menziesii) Gooseberry (maybe Canyon Gooseberry)
- Though this Ribes sp. has not been positively ID’d, it is indeed a gooseberry because it has spines.
- Not the eye-catching Ribes sanguineum flowers, but beautiful nevertheless.
- Thicket is located behind the Stone Cottage.
February 29th, 2016 by UWBG Horticulturist
Selected cuttings from the Washington Park Arboretum
(February 22, 2016 – March 7, 2016)
1) Chaenomeles cathayensis Chinese Quince
- This deciduous shrub is native to slopes and forest margins in western Hubei Province.
- Light pink flowers in spring are followed by large oblong fruit which are unpalatable raw, but make fragrant jams and jellies when cooked.
- Like other quince, Chaenomeles cathayensis’ arching branches are armed with stiff thorns.
- Two specimens can be seen in the old field nursery south of the Crab Apple Meadow near Arboretum Drive.
2) Corylopsis glabrescens Japanese Winter Hazel
- A broadly-spreading deciduous shrub native to Korea and Japan, this plant is noted for its graceful habit and fragrant yellow flowers in late winter.
- A relative of witch hazel, Corylopsis are a great way to extend the bloom time of the winter landscape.
- Some beautiful specimens can be seen on the trail to Azalea Way, west of the Witt Winter Garden.
3) Cryptomeria japonica ‘Nana’ Dwarf Japanese Cedar
- Introduced to England from China by Robert Fortune in 1842, this slow-growing conifer is one of the earliest cultivars.
- Our specimen, planted in 1960, is located north of the grove of Sequoia sempervirens in the Pinetum.
4) Osmanthus x burkwoodii Hybrid Sweet Olive
- A hybrid of Osmanthus delevayi and Osmanthus decorus, this large evergreen shrub boasts the beauty of the former with the toughness and adaptability of the latter.
- Small tubular white flowers exude a powerful jasmine fragrance in spring.
- Several specimens can be seen along Foster Island Drive near the entrance to the maintenance yard.
5) Sequoia sempervirens ‘Henderson’s Blue’ Henderson’s Blue Coast Redwood
- This vigorous, blue-gray needled tree is a cultivar of the species native to the central and northern California coast.
- The species is in the family Taxodiaceae, which also includes Sequoiadendron giganteum and Taxodium distichum, two important North American natives.
- Located north of the grove of Sequoia sempervirens in the Pinetum.
February 14th, 2016 by UWBG Horticulturist
Selected cuttings from the Washington Park Arboretum,
February 8 – 21, 2015
1) Pinus greggii
- This three-needle pine from northeastern Mexico is closely akin to P. patula but less ornamental. Its oval-conical cone clusters stay closed on the branch for several years. This specimen and the others described here can be found within Crabapple Meadow, along the east side of Arboretum Drive.
2) Pinus jeffreyi
- Native mainly of California in the Sierra Nevada and Siskiyous, this lofty tree is said to grow to 200 feet in the wild. P. jeffreyi is closely allied to P. ponderosa and at one time, it was normal to regard it as a variety of that species. Its three-needle bundles are said to give off a fruity scent when bruised.
Close-up of Pinus greggii cones
3) Pinus montezumae var. lindleyi
- This five-needle pine is native to southern and central Mexico at subtropical and cool temperate altitudes, with its best development at 7,000 to 8,000 ft. Its flexible, pendulous leaves (growing to 14 inches or longer) along with its broad, dome-shaped crown give it a distinct look.
4) Pinus pinaster
- Commonly known as the Maritime Pine, this specimen is native to southwestern Europe and north Africa. The glossy green leaves of this pine are the largest and stoutest of all two-needle pines, and it is said to be one of the best for light sandy soils. As its common name implies, it thrives in coastal maritime localities.
5) Pinus strobus ‘Fastigiata’
- A native of eastern North America, P. strobus has proven to be a valuable timber tree and one of the richest assets of our country. Its bluish-green five-needle clusters are three to five inches long, with lines of white stomata on the inner sides. Once again, all of these specimens listed here can be found within Crabapple Meadow, along the east side of Arboretum Drive.
January 31st, 2016 by UWBG Horticulturist
Selected cuttings from the Washington Park Arboretum
(January 25 – February 7, 2016)
1) Oemleria cerasiformis Indian Plum
- The Indian Plum adheres to Benjamin Franklin’s advice in Poor Richards Almanac: “Early to bed, early to rise. . . .” This shrub goes to sleep early, beginning to slowly defoliate in late summer. However, it is one of the first to leaf out, and flowers early in the spring. It can be found throughout the Arboretum, and is just beginning to awaken.
2) Ophiopogon planiscapus ‘Nigrescens’ Black Mondo Grass
3) Magnolia × soulangeana Saucer Magnolia
- The Saucer Magnolia wraps its flower buds in a fuzzy blanket for its winter nap. As winter draws to a close and spring approaches, these buds will swell and open into a glorious pink and white show. You can find this and many other specimens of this wonderful genus in our nationally-recognized Magnolia Collection (http://depts.washington.edu/uwbg/gardens/wpa/collections.php).
4) Polystichum munitum Western Sword Fern
- The Western Sword Fern spends its winter in a tightly coiled bunch. As they unfurl in spring, these are called fiddleheads, as they resemble the curled ornamentation (called a scroll) on the end of a stringed instrument, such as a violin. Fiddleheads also just happens to be the name of the UW Botanic Gardens’ Nature Preschool Program (http://depts.washington.edu/uwbg/education/Youth/nature_preschool.shtml).
5) Tsuga heterophylla Western Hemlock
- Not all the plants in the Arboretum are providing shade for Little Nemo in Slumberland. Some plants, such as conifers like the Western Hemlock, do not go to sleep during the winter. As long as it is not too cold, they will happily photosynthesize, converting water and air into sugar.
January 16th, 2016 by UWBG Horticulturist
Selected cuttings from the Witt Winter Garden at the Washington Park Arboretum (January 11-24, 2016)
Witt Winter Garden
1) Cornus sanguinea ‘Midwinter Fire’
Midwinter Fire Dogwood
- Though the species normally has red twigs and purple fall color, this outstanding cultivar has golden-yellow fall color followed by red-blushed, yellow twigs.
- This dogwood is native to northern Europe into northwestern Asia.
- Full sun is required to obtain the best winter stem color and this dogwood will slowly colonize an area via suckers from its shallow roots unless controlled.
2) Corylus maxima ‘Atropurpurea Superba’ Purple Giant Filbert
- This excellent selection of the Giant Filbert produces long purple catkins in winter followed by large purple-red leaves in spring.
- From what we have observed in the Witt Winter Garden, this specimen is resistant to eastern filbert twig blight, caused by the fungus Anisogramma anomala.
3) Daphne bholua ‘Jacqueline Postill’ Lokta, Paper Daphne
- The specific epithet “bholua” comes from “bhulu swa”, the Nepalese name for the species.
- Despite having a native range to 12,000 feet in the Himalayas, this species of Daphne is just as hardy in Seattle and requires a protected placement in the garden.
4) Hamamelis x intermedia ‘Winter Beauty’ Winter Beauty Witch Hazel
- The north end of the Witt Winter Garden contains many species and cultivars of witch hazel.
- Witch hazel flowers range from sulfur-yellow to carmine-red, while their fragrance can be absent, lightly floral or an intense citrus.
5) Sarcococca hookeriana var. digyna Sweet Box
- Sweet box is an often overlooked element of the Witt Winter Garden due to the diminutive size of its flowers, though no one can miss their intense fragrance.
- Perfectly comfortable in dry shade, Sweet Box is an excellent choice for under-planting taller shrubs or small trees such as Hamamelis.
December 22nd, 2015 by UWBG Horticulturist
Boughs used as winter decoration are often from plants in the genus Ilex. Many Ilex, or holly species are dioecious, meaning that male and female reproductive organs are separated on individual plants. This trait promotes cross-fertilization which increases genetic variability, but can decrease seed-setting efficiency. Solitary individuals are unable to be pollinated, therefore it is necessary that male and female plants grow in close proximity or female plants will not produce berries.
Selected cuttings from the Washington Park Arboretum (December 15-28, 2015)
1) Ilex cassine var. mexicana
- This large, fast-growing evergreen is native to the southeastern coast of the U.S. as well as Mexico, Puerto Rico and Cuba.
- A healthy specimen can be found in grid 13-3W, just west of Lake Washington Boulevard.
2) Ilex verticillata ‘Red Sprite’
- This female, deciduous Ilex cultivar reveals large red berries when its leaves fall.
- Our best patch can be found along the path in the Joe Witt Winter Garden planted next to the male pollinizer, Ilex verticillata ‘Jim Dandy’.
3) Ilex opaca ‘Boyce Thompson Xanthocarpa’
- Evergreen tree that grows rapidly and assumes an attractive conical shape. As with most of the American Holly clade, this tree is cold hardy but not very wind-tolerant.
- Berries can be crimson-red, yellow or orange.
4) Ilex opaca ‘Emily’
- Found in the Pacific Connections Meadow plantings, this evergreen female boasts copious quantities of vivid red fruits, starting at a very young age.
5) Ilex serrata
- Located in the deciduous Holly clade on the west side of Lake Washington Boulevard, this holly spreads and suckers to form colonies.
- Small red berries are revealed in late autumn after the leaves have fallen.
December 11th, 2015 by UWBG Horticulturist
Conifer trees occasionally mutate into unusual forms, often slow-growing natural dwarfs. Thousands of these have been in cultivation for centuries. The Arboretum has only a few in its collection, sadly neglected in grid 37-1W – a corner of the Oaks area. Here are five examples:
Selected cuttings from the Washington Park Arboretum (December 1 – 14, 2015)
1) Chamaecyparis lawsoniana ‘Lycopodioides’
- Translated: “a form of Lawson’s false cypress that looks like Lycopodium” – a genus of club moss that’s said to resemble a wolf’s foot.
2) Chamaecyparis pisifera ‘Plumosa Nana’ Dwarf Sawara Cypress cv.
- Dwarf (nana), feathery (plumose), pea-bearing (pisifera) false cypress
3) Cryptomeria japonica ‘Bandai-Sugi’ Japanese Cedar cv.
- The cultivar name has been shortened recently to ‘Bandai’ because Sugi is the Japanese word for Cryptomeria, therefore is redundant.
- All parts of the flower are hidden in this genus, hence Crypto (hidden) meria (parts).
4) Picea abies ‘Gregoryana parsonii’ Norway Spruce cv.
- See Arthur Lee Jacobson’s Trees of Seattle for an explanation of the botanic name.
- Jacobson notes that only Lawson’s Cypress has more cultivars than Norway Spruce.
5) Tsuga canadensis ‘Hussii’ Eastern Hemlock cv.
- Because of people’s tendency to call all conifers “pine” or “fir”, botanists adopted the Japanese name for hemlocks – Tsuga. Does that sound too similar to ‘Sugi’?
November 23rd, 2015 by UWBG Horticulturist
Selected cuttings from the Washington Park Arboretum, November 16 – 29, 2015
1) Arctostaphylus uva-ursi ‘Vancouver Jade’ Kinnikinnick or Bearberry
- Broadleaf evergreen and creeping groundcover with circumpolar distribution in northern hemisphere often found growing in association with Pitch Pine
- If there were still bears on Cape Cod, it would be a favorite food source for them.
- This cultivar, ‘Vancouver Jade’ is growing in containers outside the Graham Visitor Center.
2) Juniperus virginiana ‘Blue Coast’ Eastern Red Cedar
- A low growing, blue form of the Eastern Red Cedar
- Pioneer species found in mixed stands with Pitch Pine, reclaiming abandoned farms and grasslands
- Found growing under Pines in grid 36-4E, along nursery road
3) Morella pensylvanica Bayberry
Photo demonstrating the straightness of Arrowwood stems and their usage in making arrows
- Berries boiled to extract sweet-smelling wax used to make clean-burning candles
- Found growing in dry open sites along with Bearberry, Eastern Red Cedar and Pitch Pine
- Mass growing in Oaks Collection in grid 43-B
4) Pinus rigida Pitch Pine
- Rigid cone scales and stiff needles, hence its Latin specific epithet
- Used during days of wooden ships due to its resistance to decay
- Several young specimens in our Pinetum, grid 37-4W
5) Viburnum dentatum var. pubescens Arrowwood
- Large deciduous shrub with fruit a food source for songbirds
- Common name refers to Native American use of straight young stems as arrow shafts
- Old specimens located in southeastern Viburnum bed, grid 24-4W