WPA Tree Removal Notification

June 28th, 2011 by UWBG Horticulturist

WPA tree removal scheduled for Thursday (6/30):

Tsuga heterophylla (Western Hemlock)

WPA Native Matrix

Location: Along Arboretum Dr. E., field nursery fence row. Grid 28-4E

Status: Standing dead, in decline for several years prior

Targets: Pedestrians, vehicular traffic along Arboretum Dr and other UWBG plant collections

Cause: Cumulative root impacts from road and infrastructure maintenance and develpment.

UWBG tree crew will perform removal and responsible for all public safety precautions. Drive will be kept open, traffic will be detoured around work zone.

Postings on-site, Graham Visitor center and on UWBG website.

Questions?

206-543-8008

David Zuckerman

Horticulture Supervisor

UW Botanic Gardens

VM 206.543.8008

FX   206.616.2971

dzman@uw.edu

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WPA Tree Removal Notification

June 21st, 2011 by UWBG Horticulturist

WPA tree removal scheduled this week: 6/22-24

UWBG plant collection accession #:  88-62-A

Acer rubrum var trilobum (Carolina Red Maple)

Location: North Pinetum, aka Conifer Meadows, Grid 42-4W

Status: Standing Dead

Cause: Unknown, however suspect of phytophthera and abiotic stress during 2007 irrigation mainline installation. Evidence of fungal disease under bark.

UWBG tree crew will perform removal and is responsible for all public safety precautions and possible trail closures.

Postings also on-site and at Graham Visitors Center

Questions?

206-543-8008

David Zuckerman

Horticulture Supervisor

UW Botanic Gardens

VM 206.543.8008

FX   206.616.2971

dzman@uw.edu

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Aquatic Weed Symposium – July 13, 2011

June 7th, 2011 by UWBG Horticulturist

A loosestrife by any other name. . .

If you have trouble remembering this plant’s name, you might try thinking of the strife it has let loose on our wetlands.

In 2009, the Department of Ecology awarded the UW Botanic Gardens a 5-year grant for the control of garden loosestrife (Lysimachia vulgaris), a class B noxious weed mandated for control by the King County Noxious Weed Control Board. Now we’re hosting a symposium featuring the latest observations and expertise on aquatic weed management.

In his keynote address, Steve Manning, founder and president of Invasive Plant Control, Inc., will present economically and environmentally sound techniques for controlling invasive aquatic weeds. You’ll also hear from King County Noxious Weed Specialist Katie Messick and representatives from the UW Botanic Gardens and Seattle Parks Department. The afternoon will be devoted to a kayak or walking tour (your choice) through Lake Washington’s wetlands, one of garden loosestrife’s primary haunts in this region.

Designed for professional audiences, this symposium is open to everyone interested in aquatic weeds and their control.

Managing Aquatic Weeds: Challenges and Opportunities
Wednesday, July 13, 9:00 AM-3:30 PM
Graham Visitors Center, Washington Park Arboretum, 2300 Arboretum Dr. E, Seattle
Professional Credits: WSDA, WSNLA (pending)
Symposium with Kayak Tour, $55; Symposium with Walking Tour, $30
Box lunch included when you register by July 10: 206-685-8033 or online

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Farm Groundbreaking -May 22, 2011

May 22nd, 2011 by UWBG Horticulturist

“It’s really happening!” shouted the small, yet ecstatic, gathering of Farm Partnership* members, as they watched the plow turn the first soil over in the Center for Urban Horticulture’s northwest field. Farm manager, Robert Servine, knows this is just the first step of many to come before the .75 acre farm will be in full production. It’s certainly a major tangible step after months of planning with UW Botanic Gardens and UW campus grounds management, as well as between the 2 Farm Partnership organizations, to get this exciting urban farm project launched.

Thanks to the generous donation of Full Circle Farms, groundbreaking was a one-person job accomplished via use of tractor, mower and a 4-blade moldboard plow. The conditions for turning earth today couldn’t have been better. After a cold, wet spring, last week’s warmer, sunnier days, dried the field out for accessibility w/ heavy equipment. The plan now is to wait a few weeks, let the weed seed that’s now at the surface germinate, then come in and disc the field. Also, because the field’s soil is depleted of most nutrients, it’s been estimated that 600 yards of compost will need to be incorporated to bring the fertility up to standards needed to grow healthy vegetables.

The farm will contribute to the bounty of our region’s food system by producing vegetables for sale on the University of Washington campus and at the University District Farmers’ Market.

  • The Farm is a partnership between Seattle Tilth’s Seattle Youth Garden Works program and the UW Student Farm.
  • Seattle Youth Garden Works (SYGW) empowers homeless and underserved youth through farm-based education and employment.
  • The UW Student Farm is a student organization committed to growing and learning about sustainable food systems.

For more info or to get involved, contact: Robert Servine, SYGW Farm Coordinator – robertservine@seattletilth.org or (206)633-0451 x102.

Michelle Venetucci Harvey, UW Student Farm – michelle@uwfarm.org

Plow used to turn soil

 

 

 

Attaching plow to tractor

 

 

 

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Tuesdays In the Arboretum: Group Projects

May 5th, 2011 by UWBG Horticulturist

UWBG arboretum horticulture staff are taking Tuesdays by storm!  The 6 member crew, along w/ the 2 recent temporary gardener hires, plus Tuesday volunteers are now making an immediate impact on improving plant collections care and general garden aesthetics. For example, this past Tuesday, there were 10 busy bees working in the Sorbus (Mountain Ash) collection, weeding and mulching. Check out the finished product (photos). The scope of a project this size if tackled soley by the assigned Sorbus gardener,Ryan Garrison, would take about a week to accomplish, but with 10×2= 20 hands, the same amount of work was accomplishjed in only 1 day! The old addage, “Many hands make quick work!” certainly applies to our Tuesday group projects.

David Zuckerman, UWBG horticulture supervisor, several months ago decided it was time for all his expert staff to work together one day a week on a grounds project that is planned and led by a crew member designate. The chosen Tuesday project leader is based simply on an alphabetical weekly crew rotation. Yes, this idea does increase our productivity and  provides an outlet for staff leadership opportunities and, perhaps most importantly, builds team spirit and pride knowing that by the end of the day there will be a dramatic improvement in the chosen plant collection or garden.

So, if you want to join in on Tuesdays in the Arboretum and be a part of making a big difference, I encourage you to come on down and sign up as a volunteer gardener assistant.

http://depts.washington.edu/uwbg/support/volunteer.php

Bodacious Tree Rings in the Sorbus Collection

 

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PURPLE MARTIN CONDOS ARRIVE AT CUH

April 28th, 2011 by UWBG Horticulturist

Purple Martin Condos

Condos at CUH by Constance Sidles

 Yesterday the UW Botanic Gardens staff installed some new condominiums west of the greenhouses near the Center for Urban Horticulture. Oh, not for people, but for purple martins.Purple martins, you see, are our largest swallows, and they have been in decline for a long time. They nest in holes, and they like to live together in a colony. Natural habitat that suits them has vanished from our area, and for a while, so did the martins.

Then about ten years ago, one man — a water quality expert and biologist named Kevin Li — began to install houses for purple martins all over Puget Sound. He put up natural gourds for the birds among the pilings near Ray’s Café in Shilshole Bay, at Fort Lawton,  in Edmonds, and many other places. Birders began to see purple martins again in the skies over Seattle.

Before he died in a diving accident in 2006, Kevin tried twice to install gourds at UBNA. Both times, the gourds were stolen by vandals. After Kevin’s death, no one tried again. 

Until now. A couple months ago, Friends of Yesler Swamp  were brainstorming about how to improve bird habitat in the swamp (the easternmost section of UBNA). Kevin’s efforts were mentioned, and everyone immediately realized: Purple martins belong here.

Within days, the word went out to the birding community: We need money to buy purple martin gourds. Birders responded immediately, donating enough to buy eight state-of-the-art gourds. These gourds are specially designed for purple martins. They are molded from real gourds but made of UV-resistant white plastic to resist mold and reflect the hot sun, so baby birds can stay cool inside. The gourds have a little porch for the birds to perch on, and an entrance hole that is ridged so starlings and other pests cannot enter to take over the nest.

In the course of our brainstorming, David Zuckerman of UW Botanic Gardens remembered  seeing an unused cedar log at the Arboretum which could be repurposed to make a perfect stand to hold the gourds. Jerry Gettel of the Friends offered to assemble the gourds when they arrived from the manufacturer, and make a cedar arm for each one, with cordage to raise and lower the gourds so they can be cleaned when nesting season is over. 

Two weeks later, a small group of staffers gathered near the greenhouses to dig a post hole by hand. When it was deep enough, they hefted the 13-foot post with sheer muscle, and lowered it into the hole. Then they hung up the gourds carefully, one by one. We were all thrilled when the pole went up and the gourds started swinging in the breeze. Inside each gourd are clean cedar chips, waiting for a martin passerby to take note and move in. 

When (not if!!) the purple martins establish a colony at our site, we expect you will be able to see them all summer long, coursing over the waters of Yesler Cove in the heart of Yesler Swamp.  Martins love to hunt for insects over water,  and our site is perfect for them: far enough away from possible predators, close enough to a reliable food source, and within sight of comforting people (martins like us to be nearby). 

All together, our community has created a work of art that will, we hope, bring purple martins back to UBNA and Yesler Swamp. No one of us could have achieved this alone. Like everything else here in this special place, our project succeeded because we all helped, because we all respect nature, and most of all, because we try as best we can to balance the needs of people and wildlife.

As human beings, we each have within us the power to create much of our own environment, at least the cultural parts. What we choose to create is up to us — as individuals, but also as people working together. I hope when we each make our choices about how to act in both our natural and cultural worlds, that we choose to better our environment and bring out the best in each other. 

FUN FACTS ABOUT PURPLE MARTINS 

Purple Martin In Flight

• They catch and eat insects on the fly.

• Native Americans have provided nesting gourds for purple martins for centuries.

• Eastern purple martins like apartment-style houses best; western martins prefer gourds.

• Purple martins like to be around people. They are very gregarious.

• Martins are noisy birds with several different songs and calls. Males have a special song they sing at dawn.

• Males look black in dull light and deep, iridescent purple in bright sunlight.

• Females can lay up to five eggs in one gourd.

• Once eggs are laid, they take only a couple of weeks to hatch. Babies are ready to fly a month after that.

• Purple Martins spend the winter in the Amazon Basin.

• Before they migrate, they get together in large groups and then fly south together.

• Thousands of martins used to sit on the powerlines around Green Lake before their population crashed.

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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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Cherry Blossom Season is Here!

March 25th, 2011 by UWBG Horticulturist

Most 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, pls 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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Winter Plant Protection in Pacific Connections Gardens

November 22nd, 2010 by UWBG Horticulturist

"Straw Tepees" in New Zealand entry garden

No, aliens haven’t invaded the arboretum. The “straw tepees” (left), as Kyle Henegar, PCG gardener, aptly coins them, are to protect the newly planted Phormiums and other marginally hardy New Zealand plants make it through this cold spell that’s hit Seattle. It just wouldn’t seem fair to let these plants try to make it on their own since they were just planted late last summer and have yet to get their roots established.

The new Chilean Gateway garden also has several box structures dotted along the rockery hillside (bottom right). These wooden frames enveloped w/ shade cloth are protecting our new Chilean wine palms that are indeed cold sensitive.

Box over palm

Sundstrom, Gateway contractor, has also treated the palm’s crowns w/ a copper-based pesticide, to help inhibit the colonization of bacteria and fungal crown rots. If you look inside the structures, you’ll notice straw has been used to blanket the trunks and crowns as well.

Let’s all hope that these extraordinary winter protection measures pay off. We won’t know for sure until late spring or even early summer in some cases. And no, you needn’t worry about alien invasions in the arboretum.

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Cherry Pruning Time

October 8th, 2010 by UWBG Horticulturist

Our horticulture staff will begin pruning our cherry collection, mostly along Azalea Way, next week. October is our window to prune based on the life-cycle of the insect pest, Cherry Bark Tortrix -it’s not flying around seeking easy entry portals like fresh pruning wounds now. Most of our pruning focuses on  large dead branches, as well as, unwanted basal suckers below graft unions. We just don’t have the staff to detail out all the small dead twiggy growth from years of brown rot infestations. We do mulch our cherries which helps decrease amount of fungal spores to reinfect next year’s blossoms.

Also, our tree crew will be removing 7 decrepit – brown rot and decay riddled, poor health specimens. 6 are Prunus subhirtella cvs. (the most susceptible to brown rot) and one is a Prunus sargentii w/ significant crown die-back. We may decide to replant if the sites are suitable w/ brown rot resistant cultivars in the future.

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