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Coordinator’s Corner–July

July 11, 2016

Last month Ben and I met Anna Heckman, Everett’s Urban Forester, for an on-the-streets walking tour of trees in the Everett central business district for the 2016 Association of Washington Cities conference. The take-home message on the tour was that well-planned and maintained street trees are assets to a city. During the tour and at our information booth we met mayors, city councilors, administrators and managers from communities across the state.

My City is a Tree City

A leftover sticker from the AWC conference in Everett

Throughout the conference we passed out stickers that read “My City is a Tree City, is Yours?” to representatives of current Tree City USA (TCUSA)-designated cities. The enthusiastic responses we received made it clear that city leaders are proud of both the TCUSA designation and the outstanding efforts by the staff and volunteers who make it happen.

City officials let us know that they understand the value of well-managed trees. They know that trees provide economic, environmental, and social benefits and make communities attractive destinations. Trees are a worthwhile investment and investing in trees is the way to grow healthy, safe, resilient, benefit-providing community forests.

Your efforts are noticed! Keep up the good work.

The Tree City USA program is coordinated by the Arbor Day Foundation at the national level but administered by DNR’s Urban and Community Forestry program here in Washington state. The oldest Tree City USA in Washington is Ellensburg (at 33 years and counting!) but nationally, Tree City USA celebrates its 40th anniversary this year.

If your city is not a Tree City, consider beginning your journey toward tree management by applying for TCUSA recognition. Questions? We are here to help.

by Linden Lampman, program manager, coordinator, DNR Urban & Community Forest Program, 

“Quality Trees, Quality Cities” Seminar Coming to a City Near You

July 11, 2016

Communities are cleaner, healthier and more livable when trees and other public assets are well cared for. Adopting best practices for trees can improve the quality of your city while saving time and money.

DNR’s Urban & Community Forestry Program presents the seminar “Quality Trees, Quality Cities” to outline how something as simple as proper tree care can cost-effectively improve the health, quality of life and vibrancy of your community.

Topics discussed include:

  • Industry-accepted best practices for landscape tree care such as planting, pruning, etc.
  • Principles of tree selection, planning, and planting the right tree in the right place
  • Roles of city departments, public utilities, citizens and other stakeholders in managing trees
  • Strategies to maintain and manage trees with limited resources
  • High and hidden costs associated with deferred maintenance, and how to avoid them
  • Connecting tree and landscape care with other efforts to improve the quality of your city
spokane urban forest

Proper tree care can help improve cities. Photo by Guy Kramer

The seminar is free. Lunch is not provided; attendees must bring their own.

To reserve a seat at the seminar, please reply to  no later than 4:00 p.m. on the last Friday prior to the seminar you wish to attend. Please indicate which seminar you will attend (see dates below) and include your name and title. Multiple reservations may be made in one message; please include all names and titles in the body of the message.

Registration is limited to 30 participants. Details including an agenda and parking information will be provided to registrants in the week prior to each seminar. Please forward this announcement to others in your area who may find it useful.

Join us at this no-cost seminar to learn more about managing your community trees and forests for maximum benefit. Upcoming seminars will be:

Mount Vernon: Wednesday, July 20, 8:30-1:00

Poulsbo: Wednesday, August 10, 8:30-1:00

Spokane: Wednesday, August 24, 8:30-1:00

Olympia: Wednesday, September 28, 8:30-1:00

Wenatchee: Thursday, October 27, 8:30-1:00

Please contact me if you have questions or concerns.

Ben Thompson

Urban Forestry Specialist

Washington State Department of Natural Resources


New Pests of the Understory

July 11, 2016

In a time of world trade and global movement of people and products, hitchhiking insects are becoming more and more common. In the past 20 years, almost 60 exotic insect species have established in Washington state. Some of these hitchhikers can become serious agricultural and forestry pests. The risk continues to grow as global markets continue to expand.

A 2010 study led by Julieann Aukema, a forest ecologist with the National Center for Ecological Analysis and Synthesis in Santa Barbara, California, estimated that there is 32 percent risk that a wood boring insect more damaging than the emerald ash borer will be introduced into the United States in the next ten years. In addition to exotic insects that can cause significant economic impacts to agriculture and natural resources, there are a number of species affecting the natural and cultural ecosystems. The following are a few examples of newly introduced insects that are, or likely will, impact the forest understory and those that rely on it.

Viburnum leaf beetle

Viburnum leaf beetle adult.

Viburnum leaf beetle adult. Photo: T. Murray/ Washington State University

Viburnum leaf beetle larvae.

Viburnum leaf beetle larvae. Photo: T. Murray/Washington State University

The viburnum leaf beetle (VLB), Pyrrhalta viburni, was first discovered in Washington state in Whatcom County in 2004. Since then, it has spread down to King County. Recent collections of VLB have been made in Spokane. VLB overwinters in its egg state in the stems of last year’s new viburnum growth. Larvae hatch when the first leaves unfold in spring. Damage caused by feeding larvae is very distinctive and won’t be confused with any other feeding damage on viburnums. After feeding, larvae migrate to the soil to pupate for a few weeks. Adults emerge and continue to feed on foliage causing additional damage. Adult beetles feed, mate and lay eggs until first frost. Viburnum plants are not able to tolerate multiple defoliation events over consecutive years. The native Viburnum edule, high bush cranberry, is susceptible to attack. Many wildlife species rely on high bush cranberry for a reliable food source. To learn more about the viburnum leaf beetle in Washington state.

Lily leaf beetle

Lily leaf beetle adult.

Lily leaf beetle adult. Photo: E. LaGasa/Washington State Dept. of Agriculture

The lily leaf beetle (LLB), Lilioceris lilii, was discovered in Washington state just outside of Seattle in Bellevue during the spring of 2012. Thus far, LLB has only been found in Bellevue, Seattle and Issaquah. Adult beetles are very conspicuous as scarlet red beetles. Adults overwinter in protected areas and move to feed, mate and lay eggs on emerging true lilies (Lilium spp.) and fritillaries (Fritallaria spp.) in the spring. Eggs are laid in irregular rows on the underside of the lily leaves. Once eggs hatch, beetle larvae feed on the lily foliate and developing flower buds. Larvae cover themselves in excrement and other debris as a defensive tactic and superficially resemble slugs. Two key native species in the Pacific Northwest that are likely susceptible are the tiger lily, Lilium columbianum, and the chocolate lily, Fritillaria lanceolate. Learn more about the lily leaf beetle in Washington state.

Azalea lace bug

Azalea lace bug adult

Azalea lace bug adult. Photo: T. Shanan/Oregon Dept. of Agriculture

The azalea lace bug, Stephanitis pyrioides, was first discovered in Seattle, King County, in 2008. The following year, it was identified in Oregon. Lace bug nymphs emerge from eggs in the spring. Having a piercing-sucking mouthpart, the nymphs feed by removing the liquids from plant leaves creating a stippled or bronzed burn on the leaf surface. Distinctive tar spots appear on the undersides of leaves as evidence of their presence. Adult lace bugs are quite attractive with a clear, lacy appearance. In the Pacific Northwest there will be multiple generations per year. Azalea lace bugs are causing significant damage and mortality to landscaped azaleas and rhododendrons in both the Seattle and Portland areas. What is most concerning about this newly introduced insect is the degree of damage it can cause and the expanded host ranges documented in the Pacific Northwest. Jim LaBonte from Oregon Department of Agriculture has found damage on huckleberry and salal in addition to other native plant species. Learn more about the azalea lace bug in the Pacific Northwest.

Spotted winged drosophila

Spotted wing drosophila.

Spotted wing drosophila. Photo: E. LaGasa/ Washington State Dept. of Agriculture

The spotted winged drosophila (SWD), Drosophila suzukii, is a significant new pest to many small fruits and has had a major impact on blueberry, raspberry and cherry production in regions of the Pacific Northwest. SWD was first discovered in 2009 in Seattle, just shortly after its detection in California the previous year. Since then, SWD has spread across the continent. SWD adults overwinter in protected areas. When berries and other food resources become available in spring, SWD adults lay eggs into ripening fruit using an ovipositor—an appendage—with a saw-like edge. The ability to egg-lay in under-ripe fruits has made this fruit fly a serious pest. Being a fruit fly, SWD has a high reproductive capacity and fast generation time. Populations can build rapidly. Larvae feed on the flesh of fruit and quickly cause the fruit to rot. Larvae pupate outside the fruit and emerge as adults to repeat the process.

In 2013, SWD was found infested huckleberries at high elevations in the Indian Heaven Wilderness Area of the Gifford Pinchot National Forest. Almost 50 percent of the huckleberries picked turned to be infested by SWD. Since 2013, SWD has consistently been collected from infested huckleberries in high elevations (5100 feet) in remote areas. SWD was able to disperse successfully in nooks and crannies of the Mount Adams and Mount Hood forests very rapidly. SWD has likely done so in other forests where huckleberries are common.

The economic impact to agriculture and natural resources of new pests is the focus for research and investments; there are few resources available to understand the impact on natural and cultural systems. The significance of these new pest introductions into natural areas has yet to be fully realized. To put it in perspective however, humans have harvested huckleberries from the Indian Heaven Wilderness Area for almost 10,000 years without experiencing wormy, rotten berries until now.

By Todd A. Murray, Director, WSU Agricultural and Natural Resources Extension Program Unit

This article was republished as it originally appeared in the Washigton State DNR blog, Forest Stewardship Notes

Timely Tree Tips — Standards for Nursery Stock

July 11, 2016

It may feel like summer has barely arrived but the fall planting season is just 10 weeks away. This is a fitting time to get familiar with industry accepted standards for nursery stock (if you aren’t already). The American National Standards Institute‘s Z.60, American Standard for Nursery Stock establishes professional standards for trees and shrubs grown in the nursery trade.

This 109-page publication was drafted and edited by a committee of horticultural researchers and green industry professionals from across the country and was recently revised in 2014. Best of all, the standard is published by AmericanHort and free to download from their website.

ANSIz60The Z.60 addresses details about plant quality that might go unnoticed by a non-tree expert, which include but are not limited to:

  • Classifications for different types and sizes of woody plants
  • Root ball dimensions
  • Size and spacing of branches
  • Ratio of stem diameter to root ball size
  • Height-to-spread ratios for tree canopies
  • Conifer-specific standards
  • Parameters for evaluating plant quality

Here are some potential applications…

If you’re purchasing trees to plant, be sure they meet the standards before you buy. If your city requires tree planting as part of the development process, then specify that all code-required trees meet the standards. Municipal inspectors, code enforcement officers or city foresters can use the standards for guidance on when to accept or reject those code-required trees. And lastly, any contract for tree planting is not complete without a provision that requires adherence to the Z.60 standard.

The urban forest is only as good as the trees we plant in it, so let’s be planting the best possible trees.

Are You Ready for EAB?

July 11, 2016

EAB stands for emerald ash borer, an invasive, exotic, wood-boring beetle that attacks and kills ash trees regardless of species, size, age, or health. EAB hasn’t arrived in Washington state yet but all indications suggest that it will in time.

The emerald ash borer, native to China, was first discovered in Michigan in the summer of 2002–likely entering the U.S. by hitching a ride on wooden crating or shipping materials from Asia. Since its arrival, EAB has since spread to at least 26 other eastern states and the Canadian provinces of Quebec and Ontario. It was discovered as far west as Colorado in 2013 and was just recently found in May and June of this year in Texas and Nebraska, respectively.

There are an estimated 8,000,000,000 (eight billion!) ash trees in the U.S. and they are all susceptible. There are no natural predators of EAB in North America and native ash trees have no resistance or defense mechanisms to fend off an EAB attack. Sound alarming? It should. EAB is already being described by some as the most costly and ecologically devastating event for North American forests ever–eradication of an entire genera of woody plants on a continental scale.


The Emerald Ash Borer. Photo from wikimedia commons.

Anecdotally, EAB’s impact in the Pacific Northwest will not be as devastating as in other parts of the country (since ash make up a comparatively small percentage of our forests) but the impact will still be felt. Our native Oregon ash (Fraxinus latifolia) will be susceptible along with varieties of non-native white ash (Fraxinus americana), green ash (Fraxinus pennsylvanica) and many other ornamental ash species commonly planted in urban landscapes throughout the northwest.

The Washington State Department of Agriculture has already deployed traps to monitor for EAB (see article published last year in Tree Link) and is working with the Washington Invasive Species Council to quantify impacts of invasive species in Washington including EAB. Updates from these organizations are pending and will be featured in an upcoming edition of Tree Link.

In the meantime, are you ready for EAB?

Asset Management for Community Trees

July 11, 2016

The first annual Community Trees Seminar from DNR’s Urban and Community Forestry Program, “Asset Management for Community Trees,” was hosted by 9 cities across Washington state in 2015. The seminar was a half-day program discussing the different types of natural resource assessments commonly used by local governments including canopy cover analyses, sample inventories, and tree-by-tree inventories for street and park trees.


This report prepared by the Center for Neighborhood Technology

Here are the key messages from that seminar:

  • Trees are public assets and components of municipal infrastructure
  • Like other infrastructure, trees require maintenance and care to maximize useful service life and benefits, reduce risks, and control costs.
  • An asset management system (such as a tree inventory) is essential to maximizing the return on investment in our public assets

This year’s seminar, “Quality Trees, Quality Cities”, discusses the importance of adopting best practices for community trees (see article in this edition of the Tree Link); however, the need for better asset management of trees in Washington cities remains strong, and the messages conveying that bear repeating.

Check out the following for more information on asset management and tree inventory:

4 Things You Should Know About Asset Management , from MRSC of Washington.

Tree Asset Management in Portland, Oregon, from the City of Portland

Conducting a Community Tree Inventory, from Pennsylvania State University



Coordinator’s Corner — June

June 10, 2016

I was taking a lunch walk around Capitol Lake in Olympia a couple of weeks ago. It was a nice walk even though the 85 degree heat was a bit warm for my taste–72 degrees is about warm enough for me. Even with a breeze, heat rose up off the gravel and paved walkway, reminding me how warm the sunshine in May can be.

A shady spot

Park patrons enjoy a small spot of shade on a warm Olympia afternoon. Photo by Linden Lampman.

Then came a distinct pattern of hot, cool, hot, cool, as I walked in and out of shade cast by trees located on the south and southwest side of the path. With the addition of shade the breeze was cooling and the temperature quite pleasant. I noticed then that all along this side of the lake folks were enjoying the natural ‘air-conditioning’ of shade trees: picnicking, snoozing or sitting and chatting in almost each spot of shade. The trees here are still quite young, but they are already being appreciated for that wonderful summertime benefit, shade.

Radiant energy from the sun is absorbed and stored by built surfaces, sidewalks, roads and buildings. Trees shade and reduce this heat absorption, which helps cool our cities and homes. Trees transpire, or release, water vapor into the air from their leaves cooling the air, much like old fashioned swamp coolers. Temperatures can be 5 to 10 degrees cooler in the shade than in nearby areas without shade.

Did you know that shade can be quantified? Shaded streets require less maintenance than trees in full sun, resulting in cost savings to our public works departments. According to Dr. Greg McPherson, 15-year-old trees on the west side of a building can reduce energy bills by nearly 12 percent (the savings are somewhat less in cooler climates). Older trees provide even greater benefits.

With a climate that is warming, it is a wise investment to strategically plant trees now. Shade trees planted on the west and southwest of homes provide the greatest benefit. Tall deciduous trees will shade roofs in the summer, and allow sunshine to penetrate in the winter.

As you plan for planting, make sure to select the right tree for the right location. Look up (for overhead powerlines), down (get a locate for underground utilities), and all around (plant with the mature size of the tree in mind). Finally, have a plan in place to water and care for your tree as it grows into a benefit-providing asset in your landscape.

Enjoy the summer!

By Linden J. Lampman, program manager, DNR Urban and Community Forestry Program