Winter Wrap-Up: Certainly NOT Boring…

March 29th, 2013 by UWBG Horticulturist

According to Cliff Mass, UW meteorologist, our past winter of 2012-2013 was the most “boring” on record. There were no major weather events such as wind storms, artic blasts, snowfalls in the lowlands or major flooding. This was indeed good news for the UWBG horticulture staff. Instead of spending the winter cleaning up after storms and worrying about how many plants would be affected from cold hardiness issues, we were able to focus on scheduled and planned work projects for a seasonal change of pace.  Here’s a rundown of several of these projects we were able to accomplish during this most boring winter.

Reclaimed View of Azalea Way from Lookout

Reclaimed View of Azalea Way from Lookout

An adjunct to the current Pacific Connections Garden – New Zealand construction work was taking on the long overdue renovation of the Lookout rockery and reclaiming the lost vistas from the Lookout viewpoints. Arguably the most interesting rock work in the arboretum, the rockery was essentially lost under overgrown plant collections. The crew certainly wasn’t bored with the thought of what new and exciting discoveries lay under the next pruning cut. When the Lookout gazebo reopens to the public, visitors will be able to see the pond and Azalea Way from inside the newly restored structure and experience the original 1941 design intent. In other words, the Lookout is once again a lookout. Also, check out the new  Rhododendron species planted along the Lookout trail in honor of Ben and Margaret Hall’s 80th birthdays. They are major supporters and donors of UW Botanic Gardens.

Raoulia australis close-up

Raoulia australis close-up

McVay Courtyard  Raoulia australis grndcvr

McVay Courtyard
Raoulia australis grndcvr

The McVay Courtyard renovation is mostly completed now thanks to Riz and Annie and contains many new additions. The original designer, Iain Robertson,  specified renewing the 3 distinct plant groups: Bulbs, Groundcovers and Shrubs. The existing grove of Acer palmatum ‘Aconitifolium’ which were carefully worked around and a few Osmanthus are all that remain of the original tree and shrub palette  Iain’s new design incorporates elements of interesting plant architecture, habits and striking bark. Hence his use of several types of Arctostaphylus, the unusual divaricating shrub, Corokia, Rhododendron moupinense, Rh schlippenbachii, and several tidy groundcovers that mimic inanimate forms, such as Raoulia and  Bolax. For the bulk of color, Iain chose a wide-range of spring and summer flowering bulbs.  Though the garden looks a bit austere at the moment, as any newly planted landscape does, we’re looking forward to a quick and healthy establishment and growth period this spring and summer. For those that miss the striking habit of the Nolinia, no need to panic, they were successfully transplanted  to the adjacent cistern slope and new stairs  to the south.
Washington Park Arboretum is once again a UW-Restoration Ecology Network capstone site. The student group known as the “A-Team” has designed a weir system in the north “wet” zone of the holly collection. They will be continuing construction and planting this spring. Ryan and company decided it’s better to flow with nature rather than fight it. This new feature will, over time, become a healthy wetland area and will immediately reduce both UWBG and City Parks maintenance input, i.e., mowing and weed control.

"A-Team" installing weirs

“A-Team” installing weirs

The Winter Garden was in showcase form as it should be during the winter. Roy has been busy procuring new plants primarily for the new drainage area in the SE quadrant of the garden. We’re looking forward to having an updated brochure and map next winter. There’s still time to catch some of the late winter, early spring flowering plants such as Corylopsis and Magnolia.
Gardeners, Rhett and Preston, took on the tatty northeastern most corner of Rhododendron Glen. Pruning out several years worth of Rhododendron rootstock growth and removing deadwood in the grove, removal of several poor or dead specimens, and lots of sheet mulching! Wow, I’ve never seen it so good and I’ve been around these parts a long time.

Chris and Darrin spent several days up at the double parking lot along the Broadmoor fence tackling deferred storm damage cleanup and improving view corridors. I would expect ne’erdowells will think twice about using this area for their dirty deeds for quite some time.

Adding soil to Chilean Gateway via conveyor belt system along LWBlvd


Adding soil to Chilean Gateway via conveyor belt system along LWBlvd

The Lake Washington Blvd curbside area along the Chilean Gateway is vastly improved as a result of over 120 yards of new soil  brought in to create “fingers” at the toe of the slope. This new design will hopefully deter pedestrians from walking through the Gateway and stepping on our plants. Also, with improved drainage, we now can grow Elymus magellanicus without drowning its roots. There are also several new Chilean taxa planted throughout the Gateway that over time as they get bigger will create that Wow! sensation, either up close or from a distance. They include: Gunnera magellanica, Ourisia coccinea, Mitraria coccinea to name a few.

Will spring be as boring too? The UWBG horticulture staff certainly hopes so.

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Building the New Zealand Forest, Pacific Connections Update

March 11th, 2013 by UWBG Horticulturist

The 2.5 acre New Zealand  forest construction project is scheduled to be completed by the end of June.  W.S. Contractors LLC  is currently finishing up infrastructure details, including the future bus turnaround and toilet area located across Arboretum Drive from the NZ  forest in the future Australia exhibit. Irrigation system installation will begin later this month through May. Planting will begin in June. There will be approximately 10,000 total plants representing over 90 taxa for the 9 plant communities that will be represented.  Garden dedications have been tentatively set for September 13 and 14.

In tandem with the 2.5 acre NZ focal forest project, the Lake Washington Blvd street lighting upgrade through WPA is completed. The Olmsted inspired lamps installed with modern LED bulbs is a huge aesthetic and vehicular safety improvement.   Also, the lower section of the Chilean Gateway re-do will be wrapping up with new plantings in the coming weeks. Our goal for the lower Chilean Gateway is to make it uninviting for pedestrians to walk curbside and trample our plants. We accomplished this by creating raised “fingers” and small berms close to the curb by adding over 120 yards of soil amendment. The well-draining soil-mix will also provide much better growing conditions for the Chilean blue wheatgrass, Elymus megellanicus, than before.

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Seasonal Horticulture Update: “The Summer of Our Content”

November 3rd, 2012 by UWBG Horticulturist

Hydrangea by Harpa KarinUWBG Horticulture and Plant Records staff had a very busy, productive and satisfying summer. A cold wet June and early July pushed extraordinary plant growth, and, oh my, the WEEDS…Then, just as quickly as we could say, “No summer in Seattle”, the heavens went dry and lo and behold, we experienced an historic dry spell extending our summer to October 12. See King 5 news story starring, horticulturist and new plant care team member, Neal Bonham.

http://www.king5.com/news/local/If-today-stays-rain-free-driest-August-on-record-168165016.html

In hindsite, this weather pattern was just what the plant doctors ordered. A prosperous longer than usual planting window followed by a longer than usual dry period enabled us to plant into late June and then complete several landscaping projects into October.

For example, the contractor hired for constructing our 2.5 acre New Zealand eco-geographic display in the Pacific Connections Garden lucked out big time grading the steep, fortunately dry glacial-till slopes with heavy equipment. On a smaller scale, we were able to sneak a new berm in the hollies, which will eventually accommodate new specimens in the American clade. If you visit, check out the new interpretive signage.

It was all about NAIOP’s 22nd annual community enhancement project on the other side of the water at CUH. Early on in the planning stages, our associate director, Fred Hoyt, kept saying this event could be a game-changer for us. As time wore on and the project scope was scaled-back, it began to seem his prognostication would not come to pass. Now, after all is mostly said and done, if not a game-changer, it was most certainly HUGE for much needed improvements and indeed a springboard for potential future projects on our CUH campus, gardens and UBNA that will be appreciated by all for years to come.

I’m particularly excited about the huge effort that went into upgrading our plant production and corps yard area behind DRC. It’s amazing what laying down new gravel and paint can do for a tired looking nursery and storage space. And, just in the nick of time, we will now be able to overwinter lots of plants in a completely restored hoop-house.

Time now to blow the horn, as I would be remiss as a supervisor by not extending praise to my hard-working dedicated staff. Everyone contributed greatly to the enormous summer’s contents worth of planning, preparing, implementing and, of course, maintaining the grounds, gardens and plant records, including all the volunteer programs we’re involved with, throughout our botanic gardens. Here are a few of our summer accomplishments, not previously mentioned, and in no particular order:

  • A newly installed Winter Garden drainage system in the recently renovated SE quadrant. This was a joint operation between UWBG and City Parks crews. Implemented due to waterlogged soils not foreseen in the original bed renovation. May all our efforts pay off for healthy Winter Garden displays in the future!
  • A complete unabridged inventory and review of our plant collections within the Japanese Garden. Believe it or not, this is the first inventory taken since the UW gave up managment of the Japanese Garden to Seattle City Parks and Rec in 1981!
  • The Soest lawn has been renovated. Long overdue. You shoulda seen the thatch pile!
  • The incredible planning and installation for the “Music of Trees”!  Last weekend before UWBG arborist, Chris Watson, and the artist, Abby Aresty, begin the tedious task of dismantling the complex engineered designs.
  • Forest ridge middle-trail restoration in WPA. An Eagle Scout project and another joint operation between UWBG and City Parks staff.
  • Brubaker Quaking Aspen Grove maintenance project. Ask arborist assistant, Darrin Hedberg, where to find it.
  • Another successful and fun “Day of Caring”! Joint operations between all three arboretum partners: AF, UWBG and City Parks.
  • Completion of our 4th year of our 5 year DOE Garden Loosestrife grant. Although we are making headway, there are big challenges that lay ahead for this noxious weed.

And now that it is indeed officially fall and a surprising colorful one at that, it’s onward marching soldiers to another ambitious fall/winter planting season…Coming attractions include continuing McVay courtyard renovation and a Capstone REN project in the hollies to name a few.

Happy Holidays blog readers! Stay warm and cozy and renew your gardening senses by visiting UWBG!

 

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Horticulture Vignettes from a Busy Spring in the Gardens

June 25th, 2012 by UWBG Horticulturist

“Something old…”

OK, so there’s the “old”, as in “enough already”, cold wet spring weather that seems to be continuing into summer and creating a monster weed season for us. And, there’s the “old” as in a staff milestone reached in age by none other than Riz Reyes, Soest Gardener.  Sure, compared to most of our seasoned horticulture staff, he’s still just a sapling in the woods at 30, but ever so slowly, he’s beginning to put down roots and develop heartwood, true elements of perennial long-life. Happy BD Riz! It’s about time….

In our special gardens: “Old” as in “they only flower once, set seed and then die”, a condition known as monocarpism. We are fortunate to have 7 giant flowering stalks, of our Cardiocrinum giganteum, Giant Himalayan lilies, ready to open. This is a “do not miss opportunity” found in the China entry garden of Pacific Connections! Don’t delay, check ‘em out today…

Giant Himalayan Lilies ready to flower

 

“Something new…”

We just completed what I consider to be an unprecedented year of planting in the Botanic Gardens. A total of 375 plants, includes transplants, representing 157 taxa (different kinds) have been planted out for the 2011/2012 planting season. Highlights include significant additions to our core collections: maples, hollies, oaks and conifers; as well as, our special gardens, Cascadia focal forest, Woodland and Winter Garden. Of note, there were 21 large, mature specimens, mostly witch-hazel family members, transplanted by Big Trees Inc of Snohomish, from our current Pacific Connections construction project footprint to various other gardens throughout arboretum grounds. If interested in viewing our 2011/2012 planting roster, please contact dzman@uw.edu

Also, exciting new interpretive signage has been installed in our Winter Garden and Holly collections. Winter Garden signage was funded by Lake Washington Garden Club, Unit III and includes 4 interpretive signs and 1 place ID sign. The holly signage was funded by our partner Century Link Pioneers for their centennial project of 2011 and includes 5 interpretive signs and 1 place ID sign.  These new signs follow our 2004 Interpretive and Wayfinding Plan that can be viewed on-line at: http://depts.washington.edu/uwbg/docs/finaliwplan.pdf

New Interpretive Sign in Hollies

“Something borrowed…”

Thanks to being able to borrow Iain Robertson’s precious time, we now have a renewal plan for the McVay courtyard. This spring, CUH horticulture staff and volunteers, re-graded and replanted the westernmost bed, closest to the Commons. We hope to be able to implement the rest of the plan in September when the NAIOP group comes in to give CUH a new facelift! We’ll keep our fingers crossed…

Perhaps a stretch here, but certainly an important arboretum story, is the latest on the fate of the original ‘Joe Witt’ maple located along Arboretum Dr E in the Peony section. We fear it is not long for this world suffering from a malady of trunk cankers and stem girdling roots.  To make matters worse, we have lost 2 of 3, with the 3rd one barely hanging-on, of the newly planted ‘Joe Witt’ cuttings in the renovated Winter Garden bed. We have asked the Arboretum Foundation’s Pat Calvert propagation group to come to the rescue and establish new cuttings from the original tree this summer. In the meantime, Roy Farrow, just planted a large ‘Joe Witt’ specimen we procured from Molbak’s nursery last week. We’ll keep our fingers crossed that this story has a happy ending.

“Something blue…”

“Blue”  NOT as in the blue trees in Westlake Park downtown or along the Burke Gilman trail or the Blue poppies at Rhododendron Species Botanical Garden, but “Blue” as in “I gots da blues…” This column would not be complete without a bit of sad news.

We had to remove one of the City’s largest Henry Lauder’s Walking Stick or contorted hazel-nut specimen located in our Winter Garden last week due to the pervasive Eastern hazelnut blight disease. This specimen was particularly dear to my heart since I was in on the original procurement and planting back in 1993. Alas, it is no longer w/ us, but fond memories will live on in my heart forever. If you want to hear its amazing story, it’ll have to be over a Guinness at my favorite pub…

And, now on to a productive summer of new plant care in the Botanic Gardens…

 

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Phytophthora Resistant Port Orford Trials Underway in Washington Park Arboretum

February 7th, 2012 by UWBG Horticulturist

The future health outlook bodes well for what many consider to be our finest native conifer in the PNW, Chamaecyparis lawsoniana, Port Orford cedar and its many cultivars.   Port Orford cedars have been under seige for many years from its worst enemy Phytophtora lateralis, a soil-borne pathogen that is especially virulent in wet soils, and essentially spells a death-sentence to this majestic tree once its roots are infected. There is no cure, but there is a preventative practice known as plant resistance. Dr. Everett Hansen at Oregon State University has developed a Phytophthora lateralis resistant root stock. And now, thanks to the development and research labs of Monrovia, they have introduced into the trade numerous Port Orford cultivars grafted with the phytophthora resistant root stock. These grafted Port Orfords are known as The GUARDIAN Series .

Through a generous donation from Monrovia, the Washington Park Arboretum will be trialing 6 GUARDIAN Series Port Orford cultivars, as well as, the type species grown on its own root. We have chosen 5 known “hot-spots” (either cultured or symptomatic of phytophthora infested soils) throughout the arboretum. There are 2 specimens each of the cultivars and the type. We’ll be monitoring and reporting on their growth and health for a period of 5 years. Knowing the extensive research and development that has gone into The GUARDIAN Series Port Orfords, after the 5-year trial, I expect a 100% survival-rate. Stay tuned for periodic updates on this exciting plant trial study.

 

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“Day of Caring” in the Arboretum, September 16, 2011

September 23rd, 2011 by UWBG Horticulturist
And the astonishing United Way “Day of Caring”  numbers are in!
  • 103 total volunteers working 417 hours!
  • Representing 4 companies/corporations: AT&T, Japan Business Association, Microsoft, Nordstrom
  • Completing 5 projects:
    • AT&T – Holly Collection
      • 3 truckloads of blackberry and weeds hauled out, roots and all!
      • Native plant bed and holly berm weeded and mulched!
    • Japan Business Association-Pacific Connections Garden, Siskiyou Slope
      • Weeded over 1,100 linear feet of 8’wide pathways and hauled out 3 truckloads of weeds!
    •  Microsoft – Pinetum
      • Wheelbarrowed and spread over 36 yards of mulch covering over 30 tree rings and beds!
    • Microsoft – Rhododendron Glen
      • 7 truckloads of blackberry hauled out, roots and all!
    • Nordstrom – Azalea Way
      • Wheelbarrowed and spread over 5000 sq’ of mulch covering several north-end Azalea beds!
  • NOTE: 1 truckload is apporximately 3 yards.
  • Special thanks to our sponsoring partner,  The Arboretum Foundation – especially Cynthia Welte and Rhonda Bush and of course our other managing partner, Seattle Parks and Rec. Without you guys, Day of Caring wouldn’t be possible.

    Blackberry Galore in Rhododendron Glen

Microsoft staff laboring in the Pinetum


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Maintenance Improvement: Azalea Way Gravel Path

August 22nd, 2011 by UWBG Horticulturist
Azalea Way photo

An expansion of the Azalea Way lawn path is proposed.

Historically the Azalea Way lawn path experiences 8-9 months a year that are very wet making access difficult. In 2009 a crushed rock path was added to the middle of Azalea Way from Boyer Parking lot to the Woodland Garden. The proposed improvement will add 700 feet of 6 foot wide crushed rock path from the Woodland Garden to the Lynn Street Bridge Trail.

Parks anticipates the construction of the path will take place over the first two weeks in September 2011. We will work in sections to minimize the impact on users.

The project is funded by generous donation from the Arboretum Foundation.

Thank you for your support and patience during this project. 

For more project information please contact:

Lisa Chen, Park Horticulturalist Seattle Parks and Recreation 206-233-3777 or lisa.chen@seattle.gov

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Pacific Connections Update: Cascadia Bog Development

July 21st, 2011 by Jennifer Youngman, Communications Specialist
new Cascadia bog

The new Cascadia bog is a perfect solution for a wet spot.

When the Cascadia section of the Pacific Connections Garden was under construction, a natural depression appeared. Recognizing the potential for this poorly-draining area, Jason Henry of the Berger Partnership incorporated a Cascadian bog into the design. Pacific Connections Gardener Kyle Henegar explains, “Creating the bog is a long-term process as the soil conditions mature, the plants are phased in, and as Roy Farrow and I continue to procure and stage snags and rocks to create a more realistic-looking garden. I suggest visitors come visit the bog frequently to see how it ages over time and develops the beautiful patina of a native bog.”

An irrigation system will keep the soil soggy during dry months. Vegetation includes Andromeda polifolia, Ledum glandulosum and Rhododendron occidentale grown from seed collected in the Siskiyou Mountains by Collections Manager Randall Hitchin, and Darlingtonia californica from the UW Botany Greenhouse. Native plants such as huckleberry and maidenhair fern are serving as placeholders while bog plants are being phased in. In addition, the Cascadian Focal Forest contains a Siskiyou seep area along the east side of the first stairway. It too is being phased in and is currently full of container-grown native plants and plants grown from wild-collected seed.

Darlingtonia californica

Darlingtonia californica from the UW Botany Greenhouse

Rhododendron occitentale

Rhododendron occidentale grown from seed collected in the Siskiyou Mountains by Collections Manager Randall Hitchin


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Boyer Parking Lot Tree Protection

May 2nd, 2011 by UWBG Arborist, Chris Watson

One of the most widespread problems with trees in the urban environment is the failure to recognize the tree’s mature size.  If one doesn’t take into account the space required when the tree grows up, conflicts are sure to arise.  To make matters worse, the tree is often faulted for encroachment!

Several trees surrounding the Arboretum’s Boyer Parking Lot have grown up and encroached on the gravel parking spaces.  However, because we are advocates for the trees, we decided to make the parking lot yield.  A large scarlet oak (Quercus coccinea) and a grove of birch (Betula) were severely impacted by the concrete wheel stops and compacted soil over a large portion of their roots.  To remedy the problems, we moved the wheel stops to create a “root protection zone” around the trees.  Then, we used compressed air tools to break up the compacted gravel and soil.  We amended the soil with mycorrihizae and compost, then topdressed with a thick layer of mulch.  If all goes as planned, the additions will stimulate the soil biology, add nutrients and allow roots to grow in the previously uninhabitable environment.  Stay tuned for updates.

 

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UW Hydrology Study Underway In Holly Collection

April 15th, 2011 by UWBG Horticulturist

Soil test pits indicated by color push pins on map

If any of you have visited the north end of our holly collection in Washington Park Arboretum recently, you probably observed what appears to be a developing wetland. As you may well imagine, standing water where we’re trying to grow healthy hollies just don’t mix very well. See Chris Watson’s post on “Spring Pruning in the Arboretum“.   Why all the standing water? Well, we don’t know.  However, thanks to a collaboration with our School of Forest Resources hydrology professor, Susan Bolton, we may soon have the answers we seek. SFR undergraduate student, Traci Amico, has taken on this investigation as her senior capstone project.  Once we know the source of all the water, we will then be able to plan a viable drainage system that will move the water away from our cherished hollies.  Below is notice for project and will also be posted at site:

  • Notice:  10 soil pits will be dug around the site and monitored on a weekly basis in an effort to determine the source of  flooding in the area.
  • Location:  UW Arboretum, Holly Garden, Lake Washington Blvd and Boyer Ave E
  • Timeframe:  April-May 2011
  • Safety:  Soil pits will be covered and marked with cones

Study Parameters:

I. Soil Pits

a) Data collected from the soil pits will assist in determining soil types and hydrology of the site.

b) After careful consideration of other monitoring processes, soil pits were chosen as the best method for the site because of they are a minimally invasive and relatively inexpensive method of data collection. The pits can be dug with a hand held spade or auger so no heavy machinery will be on the site to further compact the soils. Pits will be dug to no more than 16 inches  and 12 inches in diameter.

c) Pits will be marked with flags and securely covered with plywood to ensure the safety of humans and pets.

d) Exposing soil horizons via soil pits will allow for the visibility of water levels, to ascertain its depth and exposure soil horizons. Monitoring will be done once a week.

e) Suggestions for soil pit locations at the site are below. Google Earth imagery was used.

II. City of Seattle

a) The City of Seattle IT Department has generously offered to let me study   their GIS imagery and plans. With these I will be able to determine the locations of any buried pipes or irrigation and assess the vegetation and hydrology patterns over the years.

III. Google Earth and Aerial Images

a) Google Earth and aerial imaging are both valuable tools in assessing previous vegetation and hydrological patterns at the site due to the historical and 3-D images and ‘real time’ views provided.


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