Summer Blooms and More

July 16th, 2015 by Sasha McGuire, Education Program Assistant
lagerstroemia indica muskogee_2917

Lagerstroemia ‘Muskogee’ – the Muskogee crapemyrtle

Summer can be a surprisingly quiet time in the garden, especially after the explosion that is spring in the Northwest.  In this 4 hour course, learn plants that bring out their best in the summer, and can survive our dry season looking fabulous. We will look at some of the lesser-known and underutilized summer interest plants in person, including bottlebrush, pineapple broom, sweetspire, chaste tree, and clethra.

In addition to identification, we will also look at bloom characteristics, foliage types, landscape functions, care and pruning tips for long-term healthy plants. We’ll also cover drought stress, given our lack of rain this year.

Professional credits include ISA, CPH, ecoPRO, ASCA and PLANET, but you don’t have to be a professional to register. Plant nerds and homeowners are welcome!


It’s not all about flowers! Sorbus himalaica has beautiful pale berries in the summer.

Learn about this hardy group of plants with instructor Chris Pfeiffer, a horticulture consultant, instructor and garden writer with over 30 years’ experience in landscape management and arboriculture. Sustainable and efficient landscape techniques are a special area of interest and expertise. In addition to her private practice, she is a consulting associate with Urban Forestry Services, Inc. and an active volunteer with local community garden projects. She previously led landscape management efforts for the Holden Arboretum and Washington Park Arboretum. A frequent horticultural speaker, Christina has taught courses in pruning, arboriculture, and landscape management at Edmonds and South Seattle Community Colleges, and at the University of Washington. She holds degrees in horticulture from Michigan State and the University of Washington and is an ISA Certified Arborist. She is co-author with Mary Robson of Month-by-Month Gardening in Washington & Oregon (Cool Springs Press 2006).

Class information:

What: Arboretum Plant Study: Seasonal Plant ID and Culture – Summer Session

When: Thursday, July 23rd, 8am-12pm

Who: Landscape professionals, homeowners, gardeners, plant enthusiasts

Where: UW Botanic Gardens – Washington Park Arboretum (2300 Arboretum Dr E, Seattle)

Cost: $65; increases to $75 one week before the class

Register: Online, or by phone (206-685-8033)

quercus robur concordia_20

Quercus robur ‘Concordia’ – that golden green color is amazing!

Big Big Flowers

July 16th, 2015 by Catherine Nelson, Adult Tours Program Assistant

maggrandifloraflwrThe Magnolia grandifloras in our collection are blooming now!  Who doesn’t love a 12-inch wide flower that smells great?   The commonly named Southern Magnolia or Bull-Bay is native to the SE United States from Eastern Texas, along the lower Gulf Coast to the Atlantic where it grows in loamy soils near water.  It has proven to be very adaptable to different soils and this has allowed for its ability to be cultivated in many different climates.  The largest M. grandifloras in their native habitat have been measured at up to 125′.  In non-native climate gardens they tend to grow to about 80′.

This tree is a valued ornamental in gardens around the world because of its large flowers and dark green glossy evergreen leaves.  It is used industrially for its beautiful hardwood to make furniture and cabinetry.  The seeds are food for native southeast squirrels, possums, quail and turkeys.  The leaves, fruit, bark and wood also are valued for their pharmaceutical properties.

Our collection M. grandifloras are located on either side of Arboretum Drive in the Magnolia section of the arboretum.   These trees are quite large and most of its flowers are high up, but there are a few on the lower branches accessible for smelling that nice citrusy scent.  Tour visitors from the Southern US assure me that this scent can be smelled at a distance down there, but up here in the Pacific NW one has to get up close to enjoy the scent.  And, speaking of tours, these trees and other summer bloomers like the Hydrangea are featured in our Free Weekend Walks for the month of July.  Join us any Sunday; we meet at 1:00 pm at the Graham Visitors Center.



Glimpse into the past – Dreams of an Arboretum at the University of Washington

July 15th, 2015 by Jessica Farmer, Adult Education Supervisor

By John A. Wott, Director Emeritus

Recently, I was browsing The Long Road Traveled by Henry Schmitz, from 1973, in preparation for a presentation about the Washington Park Arboretum.  I believe it is important to review how the leadership of the University of Washington was the catalyst to create the Arboretum. Almost all of this “glimpse” is the writing of Dr. Schmitz, but in a very condensed form.

The University of Washington seems to have wanted an arboretum from very early in its history. Shortly after his election in 1891 as a member of the State legislature, Edmond S. Meany became chairman of the legislative committee concerned with the acquisition of a new campus for the University. There are indications that he promoted the project in part by claims that it would provide an arboretum for the State as well as a campus for the University. If this is true, it was undoubtedly a method to elicit support from the lumber industry, which was not entirely without influence at that time in the state legislature. The late Herbert Condon used to relate a delightful story about a member of the legislature whom Mr. Meany was attempting to interest in the selection of the Union Bay area for the new campus-arboretum. The legislator listened to the arguments and then said, “Meany, I will help you get the area, but tell me-what in hell is an arboretum?”

Professor Edmond S. Meany

Professor Edmond S. Meany

It seems clear that for some years after the University moved to the new (and present) location selected by Dr. Meany’s committee, the development of an arboretum on the campus remained an important aim. The text calls attention to gifts of trees from the Seattle City Parks Department for planting on the new grounds.  On Arbor Day 1898, the Parks Department had presented the University with fifty assorted oaks and honey locusts. Later, Parks contributed an additional 2200 fine trees embracing almost thirty species new to the grounds, as well as a donation of a thousand perennials. These donations, along with a collection of five hundred more perennials from other sources gave impetus to a plan for the beautification of the campus.  These donations were said to “represent 42 natural orders and 179 species.”

A seed and plant exchange with eastern collectors was established by Dr. Meany to secure for the campus “as many rare and desirable species as possible.” Contributions of seeds were received from California, the Canadian Department of Agriculture, Ohio, and Pennsylvania. Dr. Meany’s home garden was used entirely for growing seedlings of tree seeds received through the seed exchange. Since the city water mains had not yet been extended to his home, it was necessary for him to carry water in pails to the nursery beds. He was especially proud of the relations he had established with Kew Gardens and was greatly concerned that the seedlings survive.

College of Forestry Dean, Hugo Winkenwerder

College of Forestry Dean, Hugo Winkenwerder

Sadly, when the campus was cleared for the Alaska Yukon Pacific Exposition, many of the trees planted in the early days by Professor Meany and others were destroyed. Nevertheless, the idea of an arboretum on the campus did not completely die. A few years later, Hugo Winkenwerder, Dean of the College of Forestry, with the enthusiastic support of Professor Meany, proposed to President Franklin Kane that the entire area below the railroad tracks be set aside for arboretum purposes. This proposal was approved by the President and the area was designated “Arboretum” on maps of the campus of that period.Progress was slow, and as the years went by, pressures developed on the campus for the construction of a golf course in the arboretum area. It was argued by the proponents of the golf course that the area could serve both purposes – the fairways and greens would occupy only part of the space and the remaining area could still serve as an arboretum. However, the golf course eventually took possession of the entire area and in late 1923 Dean Winkenwerder gloomily said that he “lost all hope of ever developing an arboretum on the University campus.”

Henry Suzzallo, UW President 1915-1926

UW President Henry Suzzallo

Although he recognized that an arboretum on campus was impractical because of the ever-changing patterns of land use by a growing university, Dean Winkenwerder did not for a moment give up the idea of developing an arboretum somewhere, and he conferred with President Henry Suzzallo to explore other possibilities. Even though it was President Suzzallo who had transformed the last campus arboretum into a golf course, he had a clear concept of the importance of a highly developed botanical garden and arboretum as a resource to the natural science departments of the University and to the people of Seattle and the State. He believed that the Arboretum should be developed jointly by the University and the City of Seattle.

Shortly after his conference with Dean Winkenwerder, Dr. Suzzallo addressed the Seattle Rotary Club to enlist the support of this important group of business and professional leaders for an arboretum in the Washington Park area. He said in part: “to the Board of Park Commissioners, that Board seems to have prepared Resolution No. 40 setting aside the entire area of Washington Park for a botanical garden and arboretum and giving the University of Washington certain privileges” (6th Day of February 1924).

Want to read the rest of the story? The Road Less Traveled is available for borrowing at the Elisabeth C. Miller Library.


July Color Appears at the Washington Park Arboretum

July 12th, 2015 by UWBG Horticulturist
Selected cuttings from the Washington Park Arboretum (July 6 - 20, 2015)

Selected cuttings from the Washington Park Arboretum (July 6 – 20, 2015)

1)  Itea ilicifolia                Holly-leaved Sweet Spire

  • Native to western China
  • Evergreen shrub growing up to 16 feet tall and 10 feet wide
  • Bears fragrant racemes of greenish-white flowers in late summer and fall
  • Located west of the Magnolia Collection near the south end of the Asiatic Maples

2)  Lomatia myricoides                Long-leaf Lomatia

  • Native to New South Wales in southeastern Australia
  • One of the hardier members of the Proteaceae
  • Honey-scented white flowers are much visited by bees in summer
  • Located across Arboretum Drive from the New Zealand Focal Forest

3)  Pterocarya stenoptera                Chinese Wingnut

  • Native to China
  • Deciduous tree to 70 feet or greater, with a trunk diameter as large as 8 feet
  • Located west of Azalea Way, north of Loderi Valley

4)  Quercus vacciniifolia                Huckleberry Oak

  • Native to western North America, mountains of the Sierra Nevada and southern Cascade Range
  • Leaves and acorns are an important food source for birds and mammals within its native range.
  • Located atop the rockery at the east end of the trail above the Gateway to Chile

5)  Rehderodendron macrocarpum                Mu gua hong

  • Native to Mt. Emei, Sichuan Province, China
  • Small deciduous tree 20 to 30 feet tall, related to Styrax
  • Located east of Azalea Way on the north end of the Rhododendron Hybrid bed

June Color Appears at the Washington Park Arboretum (Part II)

July 2nd, 2015 by Pat Chinn-Sloan
Selected cuttings from the Washington Park Arboretum (June 22 - July 5, 2015)

Selected cuttings from the Washington Park Arboretum (June 22 – July 5, 2015)

1)  Quercus gilva                    Evergreen Oak

  • Native to China and Japan
  • Reaches heights of 90-100 feet in its native range
  • Located in the Oak Collection along the South Oaks Extension Trail

2)  Rhododendron calophytum           Beautiful-face Rhododendron

  • Native to China
  • Large species rhododendron capable of becoming a tree
  • Located along trail between Loderi Valley and the Woodland Garden

3)  Sequoia sempervirons  ‘Cantab’                     Coast Redwood

  • A cultivar of the coast redwood with unique needles
  • Specimens vary in form from shrubby to tree-like
  • Located in the north end of the Pinetum, along the Pinetum Trail

4)  Thujopsis dolobrata                    Hiba Arborvitae

  • A Japanese native
  • Capable of reaching 100 feet or more in Japan, yet large specimens are rare in the Seattle area
  • Located along the south slope of the Woodland Garden

5)  Viburnum rhytidophyllum                    Leatherleaf Viburnum

  • Native to China
  • Large evergreen shrub recorded to heights of 30 feet
  • Located along the trail through the Viburnum Collection

Water-Wise Gardening

July 1st, 2015 by Sasha McGuire, Education Program Assistant

It’s hot out! With temperatures in the 80s and 90s, we sure are feeling the heat. You can bet your plants in the blazing hot sun feel it too! Since we get so little rain in the summer months, its important, (and cost-effective) to prepare for the drought.

What can you do to help your plants thrive, save water, and still have a stunning garden in July? It turns out you can do quite a bit, from choosing the right plant, to increasing the amount of water your soil can hold, to deciding if a particular irrigation system is right for you.

If you are worried about your plants fainting from the heat, or just want a low maintenance, drought-tolerant garden, check out this class. Your plants will thank you!

More class information…

Dry Garden

Drought-tolerant garden from a local water-wise gardener

What: Water-Wise Gardening

When: Wednesday, July 15th, 6:30-8pm

Where: UW Botanic Gardens – Center for Urban Horticulture, Douglas Classroom (Did we mention this classroom is air conditioned?)

Cost: $15; $20 after July 8th

How to register: Online, or by phone (206-685-8033)

UW Botanic Gardens Ranked as a Top 50 University Garden

June 30th, 2015 by UWBG Communication Staff
Picture courtesy Stephanie Colony

Washington Park Arboretum. Picture courtesy Stephanie Colony

The University of Washington Botanic Garden was ranked as one of the top University gardens, tied with three other gardens by Best Colleges Online. Gardens were scored on a number of criteria, including number of plant species, and presence of a horticultural library, education and conservation programs. With the Washington Park Arboretum enormous woody plant collection and the Center for Urban Horticulture’s numerous opportunities for formal and informal education it is no surprise that we ranked in the top of the list of 50 reviewed gardens.

2015 Summer Park in the Dark Dates

June 29th, 2015 by Sasha McGuire, Education Program Assistant

Night time is special at the Arboretum – the people and cars are gone, and the nocturnal animals move about. Night hikes are a chance for us to explore our senses, search for crepuscular and nocturnal movements in the forest and learn about night-related animal adaptations. Programs are designed for families with children aged 5-12 though all ages are welcome! We will meet at the Graham Visitors Center (2300 Arboretum Dr E)
2015 Summer DatesNight Hike Image

  • Saturday, July 11, 8:30-10:00pm
  • Saturday, July 25, 8:00-9:30pm –  CANCELED
  • Saturday, August 8, 8:00-9:30pm
  • Saturday, August 22, 7:30-9:00pm

Cost is $8 per person
Register online or call 206-685-8033

Pre-registration is required. This allows our instructor to properly plan and prepare for each class so that you and your family can get the most out of it. Drop-ins are not accepted.

US Forest Service honors Rare Care for monitoring rare species

June 27th, 2015 by Jennifer Youngman, Program Coordinator

Trifolium thompsonii (image by Julia Bent)The US Forest Service recognized Washington Rare Plant Care and Conservation – including hundreds of trained volunteers from all parts of the state who, in the past 14 years, have participated in the rare plant monitoring citizen science project – by awarding Rare Care its Regional Volunteer Award for Citizen Stewardship & Partnerships.

When Lauri Malmquist, district botanist with the Okanogan-Wenatchee National Forest, nominated Rare Care, she wrote, “As staffing and funding to the Botany/Ecology Program on the Okanogan-Wenatchee NF continue to decline, [Rare Care’s] rare plant monitoring program has played a vital role in continuing the monitoring necessary to provide critically needed information on the status of Washington State’s rare plant species. . . . Many rare plant populations have not been visited in a decade or more due to diminishing Federal funding and capacity. The scarcity of updated information on these plants puts them at risk of extirpation as a result of development, invasive species competition and other threats. All USFS Forests in Washington State have benefitted from this volunteer effort. . .”

Toward the end of each year, Rare Care consults with federal, state and other public land managers across the state to develop a list of the most urgent monitoring priorities for the coming year. Then each volunteer chooses an assignment and sets off at the proper season in search of one of Washington’s 3,500 rare plant populations. Finally, Rare Care compiles their data, maps and sketches and distributes them to the appropriate land managers and the Washington Natural Heritage Program (WNHP). Land managers use the data in making land use decisions. The WNHP maintains the state’s rare plant database and determines the status of each species.

Gentiana glauca (image by Brenda Cunningham) & Iliamna longisepala (image by Gail Roberts)This year, Rare Care volunteers are searching in the Okanogan-Wenatchee National Forest for the threatened Thompson’s clover (Trifolium thompsonii) and the sensitive obscure paintbrush (Castilleja cryptantha), longsepal globemallow (Iliamna longisepala) and Seely’s silene (Silene seelyi), among other species. To prepare for their field visits, they pore over previous reports, maps and other documentation. But there’s a catch. The documentation comes in many degrees of specificity! Plus, things change over the years. Roads are decommissioned. Trails are rerouted. Invasive species crowd out native species. Native vegetation grows into tangles of underbrush. Logging operations and fires change the face of the landscape.

Last year in the Mt. Baker-Snoqualmie National Forest, with only vague location information to go on and crossing snowfields and camping along the way, three volunteers relocated a two-square-meter population of glaucous gentian (Gentiana glauca) that hadn’t been documented since 1966. Two years ago, two volunteers traipsed through underbrush in the Okanogan-Wenatchee National Forest to find a single Wenatchee larkspur (Delphinium viridescens) remaining at a site that had grown into a young forest since the population was previously observed.

Rare Care is delighted to receive this US Forest Service Award in recognition of these dedicated volunteers and their substantial achievements.

Delphinium viridescens (image by Betty Swift) and Silene seelyi (image by Rod Gilbert)

June Color Appears at the Washington Park Arboretum

June 15th, 2015 by UWBG Horticulturist
Selected cuttings from the Washington Park Arboretum (June 8 - 21, 2015)

Selected cuttings from the Washington Park Arboretum (June 8 – 21, 2015)

1)  Cornus controversa           Giant Dogwood

  • A rounded deciduous tree bearing spreading, tiered branches and alternate, elliptic leaves, C. controversa can potentially reach 40 feet in height.  White flowers are borne in large, flattened cymes in early summer.  Following the flowers, masses of deep red fruit develop, changing to blue-black.
  • Native to China, the Himalayas and Japan, C. controversa is less cold tolerant than our native dogwoods.  This specimen is located along Azalea Way near the Hybrid Bed.

2)  Kalmia latifolila           Mountain Laurel

  • A dense, bushy shrub with glossy, dark green leaves and large corymbs of cup-shaped flowers, Kalmia latifolia is native to North America.  Thought by many to be our country’s most beautiful flowering shrub, it is the state flower of both Connecticut and Pennsylvania.
  • This specimen is located along the lower trail, near Rhododendron Glen.

3)  Quercus robur  ‘Concordia’           Golden English Oak

  • A standout specimen amongst the late spring flush of green, Q. robur ‘Concordia’ offers us bright yellow young foliage which will eventually turn color in the fall.
  • It is located on the east side of Azalea Way near the Woodland Garden.

4)  Pterocarya stenoptera           Chinese Wingnut

  • A large spreading tree with long pinnate leaves and winged green fruit produced in pendent spikes up to 12 inches in length.  Wingnuts are a member of the plant family Juglandaceae.
  • This specimen is located at the south end of the nut flats, just west of Azalea Way.

5)  Staphylea pinnata           Bladdernut

  • A deciduous shrub up to 15 feet high, S. pinnata is known for its curious bladder-like fruits in late spring and early summer.  This specimen is located amongst the True Ashes, west of Azalea Way.