July 2016 Plant Profile: Phormium cookianum

July 1st, 2016 by Kathleen DeMaria, Arboretum Gardener

Phormium cookianum at the Washington Park ArboretumThis smaller, lesser known relative of Phormium tenax is one of only two species found in the genus Phormium, and is credited as the parent that gives the graceful arching form to many hybrids. The plant is a native of New Zealand, where it is widely grown for its valuable fiber; hence the name, Phormium, which is Greek for basket. Māori used the leaves of both species for weaving baskets, mats, ropes, clothing, fishing nets and head-bands. Using a sharp mussel, leaves were cut and the fleshy green substance was stripped off down to the fiber. After the fiber (called Muka) was exposed, several more processes of washing, bleaching, dying and drying would yield fibers of various strengths and softness.

The handmade flax cording and rope had such great tensile strength that they were used to bind together hollowed-out logs to create ocean-worthy canoes. It was also used to make rigging, sails, roofs for housing, and frayed ends of leaves were fashioned into torches for use at night. Roots yielded materials to make medicine, and nectar and pollen were obtained from the flowers to make face paint.

Phormium cookianum at the Washington Park Arboretum

Combining function and form, P. cookianum boasts yellowish-orange flowers on towering spikes that, unlike the vertical flower spikes of P. tenax, angle out from the plant’s crown. The seed pods resemble long black bean pods, and can weigh the inflorescence back nearly to the ground. This Phormium can grow in sun or partial shade and will tolerate fairly dry conditions but prefers moderate water.

This summer is the first year our Phormium cookianum is blooming here in our nascent New Zealand garden, and the show is not to be missed. In the United States we mostly use Phormium as a strong architectural element in the garden and a fantastic hummingbird attractor, but in New Zealand this monocot’s connection to the history of a nation cannot be unwoven.

Botanic Name: Phormium cookianum (syn. Phormium colensoi)
Family: Asphodelaceae
Common Name: New Zealand Flax, Wharariki in Māori
Location: New Zealand Garden in the Pacific Connections, Washington Park Arboretum
Origin: Endemic to New Zealand
Height and Spread: 4-5 feet tall. Mature clumps can be 8-10 feet wide with leaves 2-3 inches wide.
Bloom Time: June/July in Seattle, November in New Zealand

Phormium cookianum at the Washington Park Arboretum

June 2016 Plant Profile: Primula bulleyana

June 1st, 2016 by Catherine Nelson, Adult Tours Program Assistant

Screen Shot 2016-05-31 at 12.42.10 PMPrimula bulleyana was discovered in China in 1906 by Scottish plant hunter George Forrest (1873-1932). It was named in honor of Mr. A. K. Bulley of Ness, Neston, Cheshire, (county in NW England) for whom [Forrest] collected.¹ He described his first sighting as follows: “Where marshy openings occurred, the turf was gaudy with the blooms of a multitude of herbaceous plants, [and] I saw miles, really, of Primula Bulleyana [sic] …”²

The UW Botanic Gardens has much smaller groupings displayed at the Pacific Connections Garden (in the China Entry Garden), but they still make a stunning impact. They are also peppered alongside the small, shaded creek in the Woodland Garden amongst Darmera and Skunk Cabbage.

Primula bulleyana is prized as a garden ornamental and has won the Royal Horticultural Society’s Award of Garden Merit. This primrose performs best in damp soils alongside streams or ponds and can take sun or shade. The grouping in the China Entry Garden is in soil with average moisture and full sun and they look particularly healthy, so it seems to be an plant that can adapt to various garden situations. The florets are also fairly tolerant of cold winter temperatures.

 

 

 

 

 

 

 

Botanic Name: Primula bulleyana

Family: Primulaceae

Common Name: Candelabra Primrose, Bulley’s Primrose

Location: Woodland Garden, Pacific Connections Garden/China Entry Garden 110-08*A

Origin: Northwestern Yunnan and Southern Sichuan regions of China

Height and Spread: 20-24” tall, up to 12” wide at base. These primroses can spread easily from their seeds.

Bloom Time: Spring

Description: semi-evergreen, herbaceous plant, bearing 5-7 whorls of florets along the stem and lanceolate leaves with a lovely reddish petiole and mid-rib.

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¹ Notes from the Royal Botanic Garden, Edinburgh 4(19): 231–232, pl. 39A, 42. 1908.

² http://www.kew.org/science-conservation/plants-fungi/primula-bulleyana-bulleys-primula

May 2016 Plant Profile: Kalmia latifolia

April 29th, 2016 by UWBG Communication Staff

kalmia photo

By Preston Pew

In western Washington, the month of May is usually marked by vivid springtime blooms of Rhododendron. A lesser known member of the same family as Rhododendron (Ericaceae), Kalmia latifolia is native to eastern North America, and is one of our most spectacular broadleaf evergreen shrubs. Its attractive qualities no doubt led both Connecticut and Pennsylvania to choose Kalmia latifolia as their state flower. Growing up to 30’ in the wild, in cultivation Kalmia slowly reaches heights of 8 to 10 feet, with a similar spread. Kalmia generally bloom later that most Rhododendron and are a good way to extend the blooming season. When not in bloom, alternate glossy deep green leaves and rounded habit give clues to its affinity with Rhododendron and Pieris. In bud, Kalmia are a special treat well before the flowers open. In early spring the small buds are covered in fine hairs. As the buds expand they develop pronounced ridges that make them resemble the dots of frosting found on decorated cakes. This fascinating geometric quality is enhanced by their arrangement in flat clusters. Inflated Kalmia buds then open to reveal five-parted shallow cups about one inch across. These groups of flowers are three to six inches across and range in color from pure white to deep pink. Several cultivars are noted for uniquely banded or spotted markings in varying tones of red and pink on their inner flowers petals. Kalmia cultivars ‘Star Cluster’, ‘Olympic Wedding’, and ‘Minuet’ are especially desired by enthusiasts for these markings. The genus Kalmia was named by Carl Linnaeus for his pupil Peter Kalm who authored a famous 18th century book Travels into North America.1

Family: Ericaceae
Genus: Kalmia
Species: Kalmia latifolia
Common Name: Mountain Laurel, Calico Bush
Location: Grid 30-3E at the intersection of Arboretum drive and the south Woodland Garden trail

kalmia photo

kalmia photo

1. Bean, W.J. Trees and Shrubs hardy in The British Isles, eighth edition. London: The Royal Horticultural Society, 1978. Print.

April 2016 Plant Profile: Brassica oleracea

April 5th, 2016 by UWBG Communication Staff

IMG_0434By Sarah Geurkink

This time of year, you may notice your winter garden plants like kale, collards, and cabbage start to elongate, and produce new, small tender leaves and florets, soon-to-be flowers, also known as raab. Often green, yellow, or purple, these clusters of flower buds emerge when the days get longer, and signify that your plants are preparing to go to seed. What you may not know is that those are edible, delicious, and nutritious! Raab tastes a lot like broccoli, but is sweeter and more tender, and is delightfully simple to cook: briefly sauté them with a little bit of oil or fat and garlic, and add them to your favorite pasta, stir-fry or scramble.

This year, the UW Farm is taking on a third site: the terrace at McMahon Hall. We broke ground on this site on April 1, and it happened to be covered in collard greens preparing to go to flower. We were able to harvest almost 20lbs of raab for the McMahon dining hall, just 100 feet below our garden.

Expect to harvest 6-10 clusters of raab per plant in the spring. Plan ahead and grow extra brassicas in July so that your spring harvest starts early!

Family: Brassicaceae
Genus: Brassica
species: Brassica oleracea
Common Name: Kale and Collard Greens
Location: UW Student farm at McMahon Hall

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March 2016 Plant Profile: Abies grandis

March 1st, 2016 by UWBG Horticulturist

By Ryan Garrison, UW Botanic Gardens Horticulturist

There is a tree on the bank of Arboretum Creek that has seen the entire history of the Washington Park Arboretum, being almost certainly a legacy of the historic site vegetation.1 The seed that would eventually become this giant likely fell to the ground about the year 1896 when the site was logged by its previous owner, the Puget Mill Company.  It would have been a tiny seedling when the land was acquired by the City of Seattle in a series of purchases in 1900 – 1904. It probably went unnoticed by John C. Olmsted and his assistant, Percy Jones, when they arrived in Seattle on April 30, 1903.2 Within a month they had outlined a plan for the City’s future park system, including Lake Washington Boulevard, a mere stone’s throw from this tree. It somehow managed to survive the myriad trials that a tree must overcome to reach maturity. It has endured such adversities as snowstorms, temperatures as low as 0°F, and hurricane force winds. Through it all, it has reached inexorably upwards, and now towers above everything around it.

Grand_fir_398

This remarkable tree is known as a Grand fir (Abies grandis), and this particular specimen truly lives up to its common name. Grand fir grows in the stream bottoms, valleys, and mountain slopes of the northwestern United States and southern British Columbia.3 It is not for board feet, but for its beauty that this tree is valued. The wood is too soft, yet too heavy in proportion to its little strength, to make first class lumber. Pulpwood offers its only commercial future, and there are so many finer pulping species that Grand Fir is little felled for any purpose and is usually left in the forest to make music and distill incense.4

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Common Name: Grand, White, Silver, Yellow, or Stinking Fir

Location:  The bank of Arboretum Creek, in grid # 22-4W. It can be seen from many places in the Arboretum, towering over its neighbors.

Origin: Northwestern United States and southern British Columbia

Height and Spread: On optimum sites in the coastal lowlands of Washington, mature grand firs reach heights of 43 to 61 m (140 to 200 ft) at 51 to 102 cm (20 to 40 in) d.b.h.; occasionally they reach 76 m (250 ft) in height and 152 cm (60 in) in d.b.h.  This tree is approximately 140 feet tall and 4.1 feet in diameter.

Bloom Time: Time of flowering may vary over several months, depending on temperatures during the weeks preceding flowering. Flowering occurs from late March to mid-May at lower elevations of most coastal locations, and in June at the higher elevations of the inland locations. The cones, mostly yellowish-green and occasionally greenish-purple, ripen from August to September of the same year, and seeds are dispersed approximately 1 month later.

 

  1. Hitchin, R., “The native forest vegetation in the Washington Park Arboretum: community analysis and curatorial recommendations”, (MA thesis, University of Washington, 1998), 49.
  2. Washington Park Arboretum Historic Review, September 2003.
  3. http://www.na.fs.fed.us/pubs/silvics_manual/Volume_1/abies/grandis.htm
  4. Peattie, Donald Culross, and Paul Landacre. A Natural History of North American Trees. Boston: Houghton Mifflin, 2007.

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 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'

December 2015 Plant Profile: Euonymus europaeus ‘Atrorubens’

November 26th, 2015 by Catherine Nelson, Adult Tours Program Assistant

euonymuseuropaensatrorubenseuonymuseuropaeus

Found in its native Europe, Euonymus europaeus ‘Atrorubens’, or spindle tree, is commonly seen as an understory shrub or small tree growing along deciduous woodland edges. Quite shade tolerant, it loves calcareous, well-drained base-rich soils and can grow up to 20’ tall. It is considered cold and drought tolerant. While labeled as invasive in some areas of the Northeast, it seems to behave itself here in the Pacific Northwest; the specimens in our collection have been here since the late 1940s and maintain their size at about 10’ x 6’. The easiest specimens to locate in the Washington Park Arboretum are in the Pinetum, tucked in between the cedars and the Coulter pines. You can’t miss them this time of year.

Traditionally, this plant’s stems were used to make spindles to twine wool and flax into yarn. It contains many medicinal properties in its roots and bark which were used by both Europeans and the Iroquois in Northeast America and Canada, where it spread widely after introduction to the new continent. While the fruits are eaten by a variety of animals in the plant’s native habitats, they are poisonous to humans.

The spindle tree is currently used as an ornamental garden feature, and the cultivar ‘Red Cascade’ has won the Royal Horticultural Society’s Award of Garden Merit. While its late spring flowers (small yellow cymes) are considered inconspicuous, its amazing orange fruits and pink sepals are brilliant in the fall and will persist into deep winter on the shrub. The ‘Atrorubens’ cultivar is prized for its bright red fall foliage, similar to its cousin the “burning bush” euonymus.

Common Name: Spindle Tree

Family: Celastraceae

Family Common Name: Bittersweet Family

Locations:
Washington Park Arboretum

  • Pinetum (555-42*B & D in 38-5W)
  • Pacific Connections Garden (555-42*A in 6-1E)

Origin: Northern Europe and UK

Height and Spread: to 20’ tall x 10’ wide

Bloom Time: late spring

November 2015 Plant Profile: Danae racemosa

November 3rd, 2015 by UWBG Communication Staff

By Roy Farrow

Danae racemosa photoNovember, I’ve found, is a difficult month to choose a garden highlight. The glory of autumn color is passing as the storms of our historically wettest month remove the most stubborn holdouts from the branches of our Acer, Stewartia, Oxydendrum and Fothergilla. Those same storms presage the return of honest-to-goodness mud, while the uplifting gems of winter such as Helleborus, Galanthus, Cyclamen and Hamamelis are still just distant dreams. Most people of sound mind are driven inside at this time for a much deserved break from the garden.

However, it is just these conditions that can spotlight the rare jewel for people still out and about. Danae racemosa is just such a jewel. During the summer months, its only request is that you keep it out of full sun. In the right shade, Poet’s Laurel is a fine, arching, bamboo-like mass of lush green foliage all year. Take a closer peak at the “foliage” and you might notice something odd. The leaves are actually just flattened stems called phylloclades. Danae spreads slowly by rhizomes.

A monotypic genus, Danae has but the one species. Currently listed in the family Asparagaceae, it has previously been located within Ruscaceae and even Liliaceae. Danae is closely related to Ruscus which also uses phylloclades rather than leaves, though Danae has terminal racemes of 1/8 in. flowers rather than have the flowers and fruit magically appear in the center of the “leaf” as with Ruscus. While the foliage of both Danae and Ruscus is quite long lasting even when cut, the fruit set of bright orange-to-red berries of Danae tends to be much more impressive than Ruscus, mostly because Ruscus requires both a male and female plant to be present, while Danae does not.

Come visit the Witt Winter Garden and you will see Danae racemosa growing in close proximity to both Ruscus hypoglossum and Ruscus aculeatus.

Name: Danae racemosa

Family: Asparagaceae (prev. Ruscaceae, Liliaceae)

Common Name: Alexandrian Laurel, Poet’s Laurel

Location: Witt Winter Garden, Washington Park Arboretum

Origin: Turkey, Iran

Height and Spread: 3’x4’

Danae racemosa with berries

Danae racemosa in the garden

October 2015 Plant Profile: Cucurbita maxima

September 29th, 2015 by UWBG Communication Staff

squash photoBy Sarah Geurink

Beautiful, packed with calories and vitamins, and easily stored for up to several months, winter squash is one of the most rewarding crops for vegetable gardeners to grow. One of our favorite squash varieties grown at the UW Student Farm at the Center for Urban Horticulture is Confection Squash. Similar to Crown Prince, popular in England, New Zealand, and Australia, Confection is a beautiful blue-grey, squat kabocha-type squash most notable for its incredible flavor, rich sweetness and texture, and edible skin. Confection squash is versatile, too—a perfect ingredient for savory soups or sweet pies alike. Note that Confection squash actually becomes more flavorful the longer it is stored, and will usually sit happily in storage throughout the winter. It is worth the wait!

Winter squash seeds should be sown in the spring, after your last spring frost and not less than 14 weeks before your first fall frost. Grow your winter squashes in a sunny area with fertile, well-drained soil with a pH between 6 and 6.5, and water your plants regularly. Confection squash is ripe when the fruit has taken on a blue-grey color, the stem has browned a bit, and the skin cannot be easily pierced with your fingernail. Expect to harvest 3-4 Confection squash fruits per plant.

 

Family: Cucurbitaceae
Genus: Cucurbita
species: C. maxima
Common Name: Confection Squash
Location: UW Student farm at the Center for Urban Horticulture