February Color Appears at the Washington Park Arboretum

February 14th, 2016 by UWBG Horticulturist
Selected cuttings from the Washington Park Arboretum, February 8 - 21, 2015

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 cones from Pinus greggii

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.

Glimpse into the past – Seeps and shifting soils

February 3rd, 2016 by Jessica Farmer, Adult Education Supervisor

by John A. Wott, Director Emeritus

Last month we discussed how rapidly trees grow and change the landscape.  It is interesting how physical landscapes also change and often actually shift and move due to changes in temperatures. Visitors to the Pacific Connection Gardens, specifically the New Zealand Forest, have seen the renovation of the Lookout which restored its former shape and size. It is perched high above a steep bluff which looks northward over Azalea Way and the large pond with the University of Washington in the distance.

The steep wall was buttressed by stone work, and originally a pathway allowed visitors to precariously descend from the area of the Lookout to the green grassy basin surrounding the pond.

Bank before reconstruction, 7/2/1967

Bank before reconstruction, 7/2/1967. Photo by B. O. Mulligan.

This entire hillside “sheds” much water and after every rain, it is quite squishy and treacherous. In fact, sometimes you can even see slippage cracks. The Works Progress Administration men laid a series of wooden pipes to assist in drainage but these have almost totally failed. Thus it has been a challenge to manage this entire rockery and drainage system.

Originally built in the 1940s, the photos shown here detail a reconstruction project of the bank and pathway in July 1967. The first photo above is before reconstruction.  The others detail the new path and stone work, all taken on July 13, 1967.

Upper portion of new steps, 7/14/1967. Photo by B.O. Mulligan.

Upper portion of new steps, 7/14/1967. Photo by B. O. Mulligan.

 

New steps down bank, 7/14/1967. Photo by B.O. Mulligan.

New steps down bank, 7/14/1967. Photo by B. O. Mulligan.

 

New steps constructed on bank, 7/13/1967. Photo by B. O. Mulligan.

New steps constructed on bank, 7/13/1967. Photo by B. O. Mulligan.

 

Top of bank after clearing and new rock work. Photo by B. O. Mulligan.

Top of bank after clearing and new rock work. Photo by B. O. Mulligan.

As you can see, it has very uneven steps, typical of the designs of that day. Over the years, there have been many slippages and the path has been closed due to safety issues.  Currently there is no easy way to ascend/descend that slope.

The current photo taken on January 24, 2016, shows a view of the rockery which obscures most of its beauty.

Current view of rockery, Lookout above, 1/24/2016. Photo by John A. Wott.

Current view of rockery, Lookout above, 1/24/2016. Photo by John A. Wott.

The last photo shows water gushing from old pipes and seepage ways.

Water gushing from hill side and banks, 1/24/2016. Photo by John A. Wott.

Water gushing from hill side and banks, 1/24/2016. Photo by John A. Wott.

UW Botanic Gardens staff is currently reviewing this entire area in order to restore its integrity, handle the drainage issues, and eventually make it all more easily accessible.

 

Late January Color Appears at the Washington Park Arboretum

January 31st, 2016 by UWBG Horticulturist

Sleeping Beauties

Selected cuttings from the Washington Park Arboretum (January 25 - February 7, 2016)

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.

February 2016 Plant Profile: Taiwania cryptomerioides

January 29th, 2016 by UWBG Communication Staff

By Ray Larson, Curator

Coffin tree branchesWhile there is an abundance of early blooms, bright bark and fragrance elsewhere in the Arboretum this time of year (particularly in the Winter Garden and Camellia Collection), winter is also a time to appreciate conifers.  One of the best and most unusual for foliar effects in February is Taiwania cryptomerioides, the Coffin tree.  We have three accessions totaling 8 trees in the Arboretum.  There are two from 1969 (Accession #315-69 A&B), four from 1996 (Accession #119-96 A-D) and two in the old nursery from 1974 (Accession #465-74 B&C).  The 1969 accessions are just south of the main Sequoiadendron grove just off Arboretum Drive E, and the 1996 plantings are at the Newton Street entrance in the Pinetum.  Using the interactive map on our website is a great way to easily locate plants.

From a distance Taiwania cryptomerioides looks a little in habit like a young western red cedar or false cypress.  But closer in its visual affinity to Cryptomeria becomes more apparent, hence the specific epithet meaning “resembling a Cryptomeria,” or Japanese cedar.  The Coffin tree is the only species in the genus Taiwania and hence is known as a monotypic genus.  The common name comes from the practice of some native peoples in its natural range using the trees for making coffins.  A tree is chosen at birth to be carved into a person’s coffin in old age.   The grove in the Pinetum is part of the ½ mile long interpretive trail, and selected specimens along the route feature information about the tree and its uses in small interpretive panels.

Coffin tree grouping

In older forests, trees with trunks up to 10 feet wide are not uncommon.  However the species is listed as Vulnerable to extensive logging in its native range.  Populations 500 years ago were much more robust and widespread.  The species is long-lived, and some older populations in Taiwan are now protected.

Ornamentally the tree has much to offer.  Perhaps most striking is the array of blue-green needles along the somewhat drooping branches.  They look sharp and stiff, but are surprisingly soft and flexible.  The textural effect is outstanding, and the narrow shape accentuates the somewhat weeping effect.  It is most attractive throughout the winter and spring seasons, and new growth is a brighter blue.  Like many conifers, older foliage does turn a brownish yellow before dropping, and this is usually most noticeable in late summer and early fall.  It does best in full sun.  In its native lands, it grows in mid to upper elevations in areas of summer and autumn rainfall but drier winters.  Despite this, it seems to do very well for us with our dry summers and wet winters.

Coffin tree needles

Next time you are in the Pinetum or near the giant Sequoias along Arboretum Drive, be sure to look for this species.  The ones at the Newton Street entrance are probably easiest to find, and if you haven’t been to this minor entrance from the Montlake Neighborhood, you’ll notice is reached from a quiet street end.

Common name:  Coffin tree
Family:  Cupressaceae
Location:  Grids 19-4E in the Sequoiadendron section, Grids 33-7E and 34-7E in the Pinetum at the Newton Street entrance
Origin:  Taiwan, northern Vietnam, Myanmar (Burma) and Yunnan, China.  Populations elsewhere in south-central China are believed to have been introduced.
Height and spread:  A large tree, that can reach over 200 feet in the wild.  It is fairly narrow in youth, and in cultivation is slower growing.  Considered the largest tree native to Asia
Hardiness:  Cold hardy to USDA Zone 8

Coffin tree with sign

January Color Brings in the New Year at the Washington Park Arboretum

January 16th, 2016 by UWBG Horticulturist
Selected cuttings from the Witt Winter Garden at the Washington Park Arboretum (January 11-24, 2016)

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.

Coniferous Trees Highlighted in January Tours

January 6th, 2016 by Catherine Nelson, Adult Tours Program Assistant

When the Olmsted Brothers first came to the Seattle area in the early 1900s, they were impressed by the size, abundance and beauty of our native conifers. Thirty years later when they designed the collection placement for the Washington Park Arboretum, they made a point of not removing our native trees, but placing the arboretum collection within a matrix of these native conifers. Eighty years later our park abounds with these tall stately beauties.

Many of the first conifers – or (mostly) evergreen trees – acquired in the collection were placed on Foster Island at the north end of the park; this site, while picturesque, turned out to be not so good for the needs of the trees themselves. Now much of our conifer collection resides in the Pinetum, which meets the needs of these plants as it is a site with better sun exposure and soil drainage. The rest of the collection is placed throughout the arboretum in areas suited to the needs of each species.

cupressusguadaloupensisCurrently the UW Botanic Gardens conifer collection includes 41 genera of conifers, comprising 216 species (not including subspecies or varieties) and approximately 2,974 individual plants. Our Sunday Free Weekend Walks in January will focus on this extensive conifer collection. With close to three thousand plants in the collection we cannot see all of them in the 90 minutes allotted, but our guides will show and talk about many of these amazing trees as well as what makes them unique in the plant world.

CguadaloupensisOne of the conifers in our collection that I have come to admire is the Cupressus guadaloupensis var. guadaloupensis, common name Guadaloupe Cypress. We acquired three of these trees in 1989 and two are still living; these plants highlight the conservation value of our collection.

Our Guadaloupe Cypress are not very big and sit unassumingly next to a path in the Pinetum. This tree caught my eye because if its exfoliating bark, which I had never seen on a conifer before, so of course I had to do some research on this tree. I’m glad I did, because it is an interesting story.

These conifers are endemic to Guadaloupe Island in the Pacific Ocean west of the California/Mexico border. Guadaloupe is a desert island and most of its moisture is received through ocean fogs rather than rain. The Guadaloupe Cypress has been cultivated since the 1800s but is rarely used in collections as it will not set seed outside its native habitat and is not necessarily resistant to cold temperatures. In the last century the tree became critically endangered in its native habitat due to a population of feral goats on the island.

A quote from The Gymnosperm Database at Conifers.org:

“For many years the species was severely limited by the grazing of goats, which reduced its population to about 3300 individuals on about 160 ha, with negligible regeneration. However, in 2005, under the leadership of Dr. Alfonso Aguirre Muñoz, the Grupo de Ecología y Conservación de Islas, A.C. succeeded in completely eradicating the goats from this large island and the trees and vegetation are now recovering. This is an uncommon bit of good news in the generally depressing landscape of rare conifer conservation.” Good news indeed.

Arboretum Map Upgraded for Smartphones

January 5th, 2016 by Tech Librarian, Tracy Mehlin

Have you even been deep inside Rhododendron Glen at the Washington Park Arboretum and wondered which direction you should walk to get to the Lookout Gazebo? Or maybe you were standing in front the most floriferous Hydrangea you have ever seen and can’t find the identification label? If you have a smartphone in your pocket then you can use the freshly upgraded map to see where you are and what plants are near by. You can also search for plants by name, keyword or accession number. Once you find a plant you love add it to your favorites. Next time you visit the Arboretum you can call up your list of favorites and see where each one is on the map.

map screenshot

The map home screen shows gardens and the highlighted collections plus parking lots. Zoom in to see plant icons.

The map was originally created in 2014 as part of a grant from the Institute of Museum and Library Services. The map worked well on desktop computers, but was challenging to use on small smartphone screens. To improve the utility of the map for visitors actually in the Arboretum the Botanic Gardens contracted with SpatialDev, a local GIS development firm, to redesign the map to be responsive to handheld devices and to utilize the GPS location function built in to every smartphone. The redesign was partially funded by a gift from the Northwest Horticultural Society.

Want to try it? There is no app to install. Simply go to the Botanic Gardens website (uwbotanicgardens.org) and navigate to the Interactive Map under the Gardens tab. If you want to use it again why not make a shortcut and add it to your home screen?

 

The map works on Android and Apple smartphones, tablets, and desktop computers

January 2016 Plant Profile: a Study on Sticks in the Witt Winter Garden

December 31st, 2015 by UWBG Communication Staff

Bare Naked in a Public Garden (a Study on Sticks in the Witt Winter Garden)

By Roy Farrow

photoI love January. The dark, wet, oppressive weather of December is past as the temperature finally drops consistently below freezing. Underfoot mud disappears overnight and we awake to glorious sunshine again. Our world seems expansive and encouraging.

I’ve come to understand that an important part of this feeling is due to the presence of “dormant” plants in the landscape. Dormant, or deciduous, plants allow the light from our very-low-on-the-horizon sun to penetrate our gardens and thus our inner beings. I qualify the word dormant because a walk through the Witt Winter Garden demonstrates that indeed it can be the leafless that are having the most fun this time of year.

As I walked through the garden this morning, my attention was torn between the just-beginning-to-crawl-out-of-their-buds witch hazels (Hamamelis sp.) and the pair of ruby-crowned kinglets gleaning from the mosaic of moss and lichen on the stems. As the birds flitted, about my eye was stolen by the multitude of buds of the winter hazel (Corylopsis sp.) and catkins of the giant filbert (Corylus maxima ‘Atropurpurea Superba’).

Magnolia stellata with frost

Quickly demanding my attention was the early winter diva Viburnum x bodnantense, of which there are three cultivars in the Witt Winter Garden: V. x bodnantense ‘Dawn’, ‘Deben’ and ‘Charles Lamont’. Other Viburnum such as V. farreri ‘Candidissimum’ and V. grandiflorum forma foetens (synonym V. foetens) will soon be following with their own fragrant display of naked gaiety. All other fragrances will eventually be forced aside by the aromatically dominant winter sweet (Chimonanthus praecox), now just a bird’s nest of sticks.

Corylus maxima 'Atropurpurea Superba'

Speaking of sticks, I often thank Miss Nature for populating our world with the many plants, particularly willows and dogwoods which are simply decorous without any adornment beyond their own skin. No one can enter the garden without their eye being caught by the midwinter fire dogwood (Cornus sanguinea ‘Midwinter Fire’). Once there, your eye may also appreciate the elegance of the bluestem willow, Salix irrorata with its white bloom and the bright golden-yellow of Salix alba ‘Vitellina’ behind it. Two newcomer willows to the Witt Winter Garden are Salix fargesii and Salix ‘Swizzle Stick’. The sleek, naked stems and large, red buds of Salix fargesii are difficult to describe without using the word “gorgeous” and the swizzle stick willow has an upright, contorted form which is colorfully impressive.

Salix 'Swizle Stick'

There are plenty more examples of naked fun to be enjoyed over the next few months, including the berries of Ilex verticillata ‘Red Sprite’, the playfully fuzzy buds of Magnolia stellata and the brief, but powerfully fragrant flowers of Abeliophyllum distichum. Last, but not least is the royal trifecta of stunning mature bark: Stewartia monadelpha, Betula albosinensis var. septentrionalis and Acer griseum. Please visit repeatedly as the Witt Winter Garden is quite dynamic and no two weeks will display the same show. Enjoy the cold!

Betula albosinensis var septentrionalis

Ilex verticillata 'Red Sprite'

Deck the Halls

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)

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.

Glimpse into the past – Trees Have a Habit of Growing

December 17th, 2015 by Jessica Farmer, Adult Education Supervisor

By John A. Wott, Director Emeritus

It is said that humans “have a habit of growing.” We grow tall in our formative years, and most of us also grow wider in the later years. We could also say that trees have a habit of growing. Tree species grow to specific heights and widths. Some smaller trees obtain their normal mature size in a few years, while the larger species may grow for years and years. In fact some large forest trees may continue to grow for hundreds of years.

In our urban sites, native conifers are capable of continuing their growth for hundreds of years. Any time the temperatures are in the 40s or above (which happens just about every day of the year here), the chlorophyll molecules are busy manufacturing sugars.

When we visit a park on a regular basis, we are very unaware that the trees we see are growing larger every day. I remember someone once saying, “I visit the Arboretum every year, and the plants have not changed at all over the last 25 years.” Rubbish! The Arboretum changes daily due to this continuous tree growth. The conifers gradually grow larger and larger and suddenly, their size can “ambush” us. I am sure most of us have had the experience of suddenly realizing that the cute little evergreen we planted 20 years ago is now overpowering the house.

View of Section C, Nursery and Seedling beds

1. A view of Section C Nursery and the Seedling Beds where thousands of plants have been started. Fred Leissler, asst. dir. 1935- 37

This series of pictures shows such a progression of growth. The first picture above, taken by Fred Leissler, Assistant Park Director in 1935, shows seedling trees of western hemlock (Tsuga heterophylla)  planted along Section C of the Nursery and Seedling Beds as a screen and windbreak. The picture notes indicate that thousands of plants had been started there in those sunny beds. Note that Arboretum Drive E. is a wide lane.

Pictures 2 and 3, below, show the same trees on January 15, 1950, just 15 years later, and already making a sizeable screen.

46b. Hedge of Western Hemlock, 30 ft., A. macrophyllym, 1-15-1950

Hedge of Western Hemlock (Tsuga heterophylla) outside nursery. Trees of Oregon maple (Acer macrophyllum) on left. January 15, 1950. By E.F. Marton, UW

 

Hedge of Western Hemlock (Tsuga heterophylla) outside nursery. Tallest specimen about 30 ft. January 15, 1950. By E. F. Marton, UW.

Hedge of Western Hemlock (Tsuga heterophylla) outside nursery. Tallest specimen about 30 ft. January 15, 1950. By E. F. Marton, UW.

Along Arboretum Drive, other species of conifers were planted in rows during this time and into the late 1950s. These were mostly native species, such as the Western redcedars (Thuja plicata) in pictures 4 and 5 below.

4. Hedge row of Leyland cypress, December 14, 2015

4. Hedge row of Western redcedar (Thuja plicata), December 14, 2015

 

46e 0151214_141442

5. Hedge row of Western redcedar (Thuja plicata), December 14, 2015

However, one of the final plantings of this type were of the newly introduced Leyland cypress (× Cuprocyparis leylandii), which is a cross between the Monterey Cypress (Cupressus macrocarpa) and the Alaska yellow cedar (Xanthocyparis nootkatensis). These were sent to us from Hillier Nurseries in England via the Institute of Forest Genetics in Placerville, CA. They were planted at the north end of Arboretum Drive E., just to the west of the Greenhouses (and current Plant Donations area).

These trees, while extremely fast growing, have proved to be inferior landscape trees. They have weak, soft wood, and are prone to wind damage. They are best used as a tall sheared hedge and kept under 20 feet. Our trees were planted out in the late 1950s and grew rapidly. One large specimen, shown below in picture 6, toppled on December 10, 2015, probably due to root removal by the lowering of Arboretum Drive for the construction of the Graham Visitors Center in 1985 (west side), and the recent heavy rains. This is an excellent pictorial example of continuous tree growth and how conifers grow and grow and grow. It is also an example of the need for continual evaluation and management of trees and their appropriate placement in the landscape.

6. Toppled Leyland cypress, December 10, 2015

6. Toppled Leyland cypress, December 10, 2015