Harbinger of Spring in Seattle – Early flowering cherries on Azalea Way!

March 25th, 2013 by UWBG Horticulturist

bird enjoying cherry flowersMost visitors experiencing the beauty of our historic Azalea Way flowering cherries from now through May probably have no idea of how intensive maintaining their health and prolonging their longevity truly is for the UW Botanic Gardens horticulture staff.   Just ask our Integrated Pest manager, Ryan Garrison. Ryan with staff support spends many a day throughout the year monitoring and controlling the numerous diseases and insect pests our 175 plus cherries are prone to suffer from. Our rainy climate doesn’t help one bit either, especially when dealing with our most notable disease during blossom time;  a fungus known as Cherry Blossom Brown Rot. Yucko!  The good news is any new cherries we plant need to show a reasonable level of resistance. The not so good news is many of our older earlier bloomers, the ones extremely susceptible to the brown rot fungus,  need to be protected with fungicide applications during their bloom period.  As with all of our pest issues, we start with cultural and mechanical control efforts before resorting to chemical controls. The following Integrated Pest management (IPM) program discusses our best management practices for the control of blossom brown rot.  If you are interested in planting cherries for your home garden, I’ve included a list of cherries recommended for our PNW climate, all have good to excellent resistance to blossom brown rot.

Cherry Blossom Brown Rot - causal fungal agent known as Monolinia fructicola. The fungus overwinters on infected twigs and dried fruit on the tree or ground.  The fungal spores are spread in the spring by wind and rain through the blossoms, causing twig dieback.  As part of the UWBG IPM program, moving toward our goal of eliminating the use of all synthetic pesticides is our ultimate goal.

IPM relies on many strategies to manage plant health care. 

  • Proper ID of the pest and its life cycle
  • Regular monitoring of the plants
  • The use of physical, mechanical, cultural, and biological controls
  • Chemical controls used as a last resort*
  • Least toxic chemicals used

* All spray applications are in compliance with WSDA pesticide regulations.  Sign postings are located at all entrances and Graham Visitor Center. Spray applications are scheduled based on timing and weather. We do our best to apply when public are not present. For more information, please contact, David Zuckerman at 206-543-8008 or dzman@uw.edu

The cherries are pruned in early fall  to remove infected twigs and improve air circulation.  Tree rings are given a fresh coat of mulch in the fall to bury any infected plant material that may be on the ground.  In our Cherry Replacement program we are only using cultivars that are resistant to Blossom Brown Rot.

Cherries recommended for the PNW:

    • Prunus ‘Berry Cascade Snow’
    • Prunus ‘Kwanzan’ syn. ‘Sekiyama’
    • Prunus ‘Pink Flair®’
    • Prunus ‘Royal Burgundy’
    • Prunus ‘Shirofugen’
    • Prunus ‘Shirotae’
    • Prunus ‘Snow Goose’
    • Prunus subhirtella var. ascendens
    • Prunus x yedoensis ‘Shidare Yoshino’
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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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WPA Historic Event: Tree Transplants for the Ages

November 11th, 2012 by UWBG Horticulturist

90″ root balls ready to go.

I think it’s safe to say that history was made last Tuesday, Nov. 6, and it had nothing to do with election day. It was the day the largest trees ever, 3 “Southern Beeches”, were transplanted in the arboretum to their new homes in the construction of the New Zealand focal forest of Pacific Connections Garden.

Here are the “WOW!” factoids:

  • Big Trees of Snohomish and Magnum Crane from Kent, accomplished the amazing feat.
  • It took a 175 Ton crane to do the job!
  • Their rootballs each weighed between 12,000 and 20,000 lbs!
  • The trees were between 30′- 40′ tall with up to 20′ canopy spreads!
  • Their trunks were between 8″-10″ calipers!

Utube video provided by AF staff, Rhonda Bush

Let’s wish these trees luck in adapting and establishing into their new home.

Hoisting up via crane

Photos taken by Todd Holms of Big Trees this one showing one of these Goliath trees suspended by crane over its new home.


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WPA Goes Hollywood: Release of film “The Details”

November 11th, 2012 by UWBG Horticulturist

It’s been a few years since many of our staff witnessed a film shoot in the arboretum featuring Spiderman star, Tobey Maguire. Now, the big payoff, “The Details” has hit the big screen. It garnered a 3-star review in Friday’s Times “Weekend Plus” by John Hartl.

http://seattletimes.com/html/movies/2019636923_mr09details.html

What are you waiting for! Go check it out and keep your eyes open for arboretum landmarks.

 

 

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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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RECENT WPA TREE REMOVAL NOTIFICATIONS

October 12th, 2012 by UWBG Horticulturist

This notice is to inform you that the following arboretum trees/UWBG plant collections are scheduled to be removed first half of October. All removals, including public safety and posting details, will be conducted in-house by the UWBG tree crew. 

  • Hazardous mature Fraxinus latifolia, Oregon ash, leaning over Interlaken Blvd in the Holly display
  • Standing dead UWBG plant collection #497-48-C, Cupressus arizonica var nevadensis, Arizona cypress, south Arboretum Dr, across from Pacific Connections – Siskiyou Slope
  • Standing dead UWBG plant collection # X-372-D, Chamaecyparis lawsoniana form, Port Orford, in the Pinetum. Cause: Phytophthora lateralis, systemic soil-borne disease
  • Standing dead UWBG plant collection, Chamaecyparis lawsoniana, Port Orford, in grove across from Graham Visitor Center. Cause: Phytophthora lateralis, systemic soil-borne disease 
  • Standing dead western hemlock, Tsuga heterophylla, located in Woodland Garden

Further questions or comments? Please contact David Zuckerman @ dzman@uw.edu or call 543-8008.

 

 

 

 

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WPA Tree Removal Notice

June 26th, 2012 by UWBG Horticulturist

Several standing dead UWBG tree collections are scheduled for removal beginning this week. Removals, public safety and postings, all handled via UWBG tree crew.

The list includes:

  • 225-89-B Cupressus guadalupensis – Pinetum 34-4W
  • 1550-45  Oxydendrum arborea – Rh. Glen 12-7E
  • 52-10  Araucaria araucana – PC Ch. Gateway 1S-4E
  • 164-49-A Acer tegmentosum – Asiatic Maples 27-B
  • 37-02-A Clerodendrum trichotomum – GVC 42-4E
  • 418-55-A Sorbus japonica – Sorbus 20-4E

Thank you,

David Zuckerman

Manager of Horticulture and Plant Records

UW Botanic Gardens

VM 206.543.8008

FX   206.616.2971

dzman@uw.edu

 

 

 

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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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Get Your Hands Dirty this Earth Day

April 7th, 2012 by UWBG Horticulturist

Join the Student Conservation Association (SCA), the University of Washington Botanic Gardens (UWBG), and Seattle Parks and Recreation for a day of fun service projects at the Washington Park Arboretum.

When: Saturday, April 14, 2012. 9:00am – 2:00pm

Where: Washington Park Arboretum, 2300 Arboretum Drive E, Seattle 98112. (Meet in the Meadow—a 5 minute walk south of the Graham Visitors Center.)

What to bring: water bottle, sack lunch, travel mug for a hot drink, sunscreen, rain gear, long pants, layers of clothing, and boots. Some snacks & drinks will be provided. Tools, gloves, snacks, environmental education, and project materials will be provided.

photo
Student volunteers having fun spreading mulch at the Arboretum at a previous Earth Day event.

PLEASE RSVP to the SCA

For more information and to register, visit thesca.org/seattle, email wanw@thesca.org or call 206.324.4649

Printable Flyer 

Map of project locations at Washington Park Arboretum

In partnership with the Seattle Parks and Recreation, UW Botanic Gardens and Woodland Park Zoo.

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Early Rhododendrons Blooming at the Washington Park Arboretum

February 28th, 2012 by UWBG Horticulturist

cuttings photo
1)  Rhododendron arboreum hybrid

  • The earliest, longest blooming rhododendron in the Arboretum (November-March!)
  • Due to its floriferous nature, even in the coldest winters when it sustains bud blast from a deep freeze, it usually never fails to flower afterwards.
  • Located in Witt Winter Garden, this rhododendron is worthy of naming and becoming a WPA plant selection.

2) Rhododendron ‘Cilpinense’

  • Hybrid between parents of two Chinese spp., Rh. ciliatum and Rh. moupinense
  • Compact, low-growing rhododendron that blooms in late February into March
  • Nice grouping located in Winter Garden, bed F

3) Rhododendron mucronulatum ‘Cornell Pink’

  • My personal favorite harbinger of spring rhododendron
  • Species is native to Korea, a.k.a. Korean rhododendron
  • Can’t miss ‘em beginning to flower at north end of Azalea Way, x from GVC

4)  Rhododendron ririei

  • Large rhododendron, best in partial-shade for vivid magenta-purple color to show
  • Native to Mt. Omei, W. Szechwan and flowers late February – early March.
  • This specimen is located in Loderi Valley, southwest bed with hemlock cvs

 5)  Rhododendron strigillosum

  • Rare, rich red flowering rhododendron in late February – early March
  • Stiff, bristly leaf-stalks and narrowly-oblong leaves provide added texture and show

Several new specimens located in Witt Winter Garden.

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