ELISABETH C. MILLER LIBRARY UW Botanic Cardens Box 354115 Seattle, WA 9,8195-4115 JUN 3 0 2016 §ton Park Arboretjfefrt^ll The “Washington Park Arboretum Bulletin” is a benefit of Arboretum Foundation membership. For information on membership or advertising opportunities, contact the Arboretum Foundation at 206-325-4510 or info@arboretumfoundation.org. Graham Visitors Center Open 9 am- 5 pm daily. Open on these holidays: Presidents Day, Memorial Day, Fourth of July, Labor Day. The Arboretum is accessible by Metro Transit buses #11, #43 and #48. For more information: www.metro.kingcounty.gov Washington Park Arboretum The Arboretum is a 230-acre dynamic garden of trees and shrubs, displaying internationally renowned col- lections of oaks, conifers, camellias, Japanese and other maples, hollies and a profusion of woody plants from the Pacific Northwest and around the world. Aesthetic enjoyment gracefully co-exists with science in this spectacular urban green space on the shores of Lake Washington. Visitors come to learn, explore, relax or reflect in Seattle’s largest public garden. The Washington Park Arboretum is managed cooper- atively by the University of Washington Botanic Gardens and Seattle Parks and Recreation; the Arboretum Foundation is its major support organization. Arboretum Foundation The Arboretum Foundation’s mission is to create and strengthen an engaged community of donors, volunteers and advocates who will promote, protect and enhance the Washington Park Arboretum for current and future generations. 2300 Arboretum Drive East, Seattle, WA 98112 206-325-4510 voice/ 206-325-8893 fax info @ arboretumfoundation . org www. arboretumfoundation. org Office hours: 8:30 am-4:30 pm weekdays Gift shop hours: 10 am-4 pm daily, closed holidays OFFICERS OF THE ARBORETUM FOUNDATION BOARD OF DIRECTORS Paige Miller, Executive Director Jim Reid, President Roger Williams, Vice President Diane Adachi, Vice President Linda Strout, Secretary Sherrey Lueljen, Vice President Paul (Skip) Vonckx, Treasurer Jason Morse, Vice President BOARD OF DIRECTORS Steve Alley Meg Harry Terry Holme Carolyn Kitchell Noriko Palmer Chris Pendl Jeanne Peterson Anne Phelps Patricia Simpson Craig Trueblood Trina Wherry Jenny Wyatt EX OFFICIO Paige Miller, Executive Director, Arboretum Foundation Sarah Reichard, Ph. D , Orin and Althea Soest Chair for Urban Horticulture and Director, University of Washington Botanic Gardens Jesus Aguirre, Superintendent, Seattle Parks and Recreation — University ofWashington Botanic Gardens — The University ofWashington manages the Arboretum’s collections, horticultural programs, facilities and edu- cation programs through the University of Washington Botanic Gardens. It owns some of the land and buildings and all of the collections. 206-543-8800 voice / 206-616-2871 fax Office hours: 9 am-5 pm weekdays www.uwbotanicgardens.org Sarah Reichard, Director Seattle Parks and Recreation The City of Seattle owns most of the Arboretum’s land and buildings. Seattle Parks and Recreation is respon- sible for park functions throughout the Arboretum and manages and operates the Japanese Garden. 206-684-4556 voice / 206-684-4304 fax Washington Park Arboretum Bulletin Niall Dunne, Editor Constance Bollen, cbgraphics, Graphic Design Cynthia E. Duryee, Copy Editor Miller Library staff, Proofreading/Factchecking EDITORIAL BOARD Betsy Anderson, Garden Historian Sc Landscape Designer Janine Anderson, Garden Designer Sc Writer Constance Bollen, Graphic Designer Walt Bubelis, Professor Emeritus, Edmonds Community College Cynthia E. Duryee, Writer/Editor Daniel J. Hinkley, Author, Lecturer, Horticultural Consultant Daniel Mount, Garden Designer Christina Pfeiffer, Horticultural Consultant Richie Steffen, Coordinator of Horticulture, Elisabeth C. Miller Botanical Garden Brian R. Thompson, Manager and Curator Elisabeth C. Miller Library, UW Botanic Gardens Cass Turnbull, Plant Amnesty Founder Phil Wood, Garden Designer Sc Writer John Wott, Director Emeritus, Washington Park Arboretum BOTANICAL EDITOR Randall Hitchin, Major Gifts and Outreach Manager, Arboretum Foundation CONTRIBUTING EDITOR Rebecca Alexander, Plant Answer Line Librarian Elisabeth C. Miller Library, UW Botanic Gardens SUMMER 2016 VOLUME 78. ISSUE 2. © 2016 The Arboretum Foundation. ISSN 1046-8749. CONTENTS 2 Randall— Paige Miller 3 Nurseries to Visit on the Olympic Peninsula —Janine Anderson 8 Hidden Treasures of the Arboretum Rosa x cantabrigiensis ‘ Red Wing’ — Daniel Mount 1 0 Getting to Know our Native Bees —Hillary Sardihas 1 5 Climate Change: Another Potential Threat to Native Bees —Janet Marinelli 1 8 Reluctant City — A Brief Account of Envi- ronmental Design in Seattle. Part 2: Re- trieving Nature’s Outline— Betsy Anderson 24 Plant Answer Line: A Flower’s Vanishing Scent— Rebecca Alexander 26 In a Garden Library: Award-Winning New Books for Pacific Northwest Gardeners — Brian R. Thompson ABOVE: A Franklin tree ( Franklinia alatamaha) blooming at the north end of Azalea Way in late summer. ON THE COVER: Rhododendron Glen at Washington Park Arboretum provides serenity and cooling shade during hot summer days. Randall dgar. Ichiro. Macklemore. These folks are iconic in Seattle. We know them instantly by one name only. The Arboretum has its own one -name icon, someone everyone speaks of by his first name only: Randall. Randall Hitchin is the guru of the Arboretum. He is the one everyone turns to for help or advice. “Randall, here is this leaf from a plant that grows in my back yard. Can you identify it for me?” “Randall, here is a picture of a really cool shrub in the Witt Winter Garden. What is it? ” “ Randall, our unit is having a meeting in the Arboretum next month. Will you give us a tour? ” And, whatever the request, Randall responds. He’ll stroke his chin, peer over his glasses, and then share his thought with a turn of phrase that is unique, fun and memorable. If you have taken an Arboretum tour with him, you have heard his vivid word pictures. How the native peoples used the big leaf maple and its enormous leaves: “like a giant paper towel dispenser.” The contents of the sewer main that is built into the Arboretum’s Wilcox footbridge: “affluent effluent.” For nearly 2,0 years, he has worked in the Arboretum: first as the manager of the plant collections here for the University of Washington, and more recently working with volunteers and doing outreach and fundraising for our Foundation. His love for the Arboretum and his knowledge of its trees and shrubs just shines. I have teasingly said to many old-timers that he knows the Arboretum better than anyone alive. No one has yet challenged my claim. But, Randall’s true gift and calling is teaching. His is the very rare combination of deep knowledge and attention to detail, passion for his subject, and an impish sense of fun. He loves to share what he knows with others, and to inspire them. Over the past year he has been talking with me about his future plans. This winter he reduced his time with us, so he could begin teaching plant identification at South Seattle College. Updating the course material and making it his own has been exhausting work, but he clearly loves it and wants to do more. He also began an ambitious project to plant a world-class mahonia collection in the college’s campus arboretum. So, he is being pulled elsewhere— and he is leaving our staff. All of us want him to stay connected to the Foundation and the Arboretum, and we will be happy to have him on a contract to organize the Walks and Talks programs for our Arbor Circle members and for other special projects. I am so grateful for his contribution to the Arboretum over all of these years, and for his support for me and his collaboration with our team. Not having him here in the office will leave a void. Who will answer those questions, guide those memorable tours? Who will lighten our day with gentle, playful wit? He is irreplaceable. That is why he is our one -name icon. We wish you the very best, indeed, Randall. Cheers, Paige Miller, Executive Director, Arboretum Foundation 2 ' Washington Park Arboretum Bulletin on Nurseries to Visit the Olympic Peninsula By Janine Anderson he Olympic Peninsula has numer- ous attractions, and summer is the best time to visit. The million- acre Olympic National Park has miles of wilderness coast, endless trails through scenic wonders, and a maj estic rainforest. Among the peninsula’s many other treasures are the Victorian seaport of Port Townsend; the ferry crossing the Strait of Juan de Fuca from Port Angeles to Victoria, BC; and Cape Flattery at the northwestern-most point in the continental United States. For gardeners on the go, three specialty nurseries stand out as destinations all on their own. Far Reaches Farm, Chimacum Woods and The Desert Northwest are worth the time and effort to visit— not just for the amazing plants they offer, but also for the creative individuals who nurture them. Far Reaches Farm Located on six bucolic acres just 10 minutes from downtown Port Townsend, Far Reaches Farm isn’t really a farm. Opened in 2005 by Kelly Dodson and Sue Milliken, Far Reaches Farm is a regional treasure, as well as a specialty nursery. The story of Far Reaches Farm. Before starting gg . ~ their nursery, Kelly and Sue had already been plant purveyors for decades; Kelly previously owned Reflective Gardens in Poulsbo, Washington, while Sue had a nursery in Vermont. The seeds for their current joint endeavor were TOP: Brazilian native Alstroemeria isabellana flowers in July and August. (Photo by ar Reaches Farm) INSET: Sue Milliken and Kelly Dodson of Far Reaches Farm. (Photo by Janine Anderson) Summer 2016 3 ■ sown in 1997, when they met on a seed- collecting expedition to China. Both have had lifelong passions for plants. Kelly grew up in Puyallup— where his parents built a greenhouse for his cactus collection when he was just 11 years old— and he majored in horticulture at Washington State University, while Sue earned a biology degree from Middlebury College in Vermont. Most of the plants Kelly and Sue offer are propagated at the farm. Nothing harmful is employed in plant production. Organic or biological methods are used for insect and disease control. Weeding is done by hand, and hazelnut shells are used for mulching and weed suppression. The nursery’s custom potting soil mix contains no peat moss, owing to the unsustainable nature of peat moss harvesting. Slow-release fertilizer is used to minimize nutri- ent leaching. Kelly and Sue’s thoughtful practices are good for the plants, but also for the surround- ing ecosystem. A large wetland on the property is home to frogs, salamanders and newts, as well as ducks, herons, songbirds and rails (small, shy wading birds) , and Kelly and Sue want to prevent chemicals from reaching the wetland. The populations of birds and bees have increased since Kelly and Sue opened the nursery: Brewer’s blackbirds nest in potted plants, and Anna’s hummingbirds spend winter nights in the greenhouse among the most nectar-producing flowers. Killdeer lay eggs on a garden berm just a few feet from the entry drive. These reliable returnees have halted the expansion of an entry garden. Here, a dramatic assemblage of xeric plants, anchored by large boulders and two stately Yucca rostrata, is followed by a long strip of uncul- tivated soil, where the killdeer nest and raise several clutches throughout spring and summer. The plants. Far Reaches Farm offers unusual plants from around the globe that often cannot be found at conventional retail nurser- ies. Many of its offerings are grown from seed collected during Kelly and Sue’s multiple expedi- tions to China and the adjacent Sino- Himalaya area. Among the mouth-watering tempta- tions you might encounter on a summer visit are nine varieties of Agapanthus ; six different types of manzanita (Arctostaphylos) , including several that can be used as groundcov- ers; six species of red hot poker ( Kniphofia ) ; some knockout Peruvian lilies ( Alstroemeria ); various types of giant Himalayan lily ( Cardiocrinum ); and 30-some varieties of Crocosmia. Many of the plants offeredfor sale are displayedin the nursery’s shade house or in one of its j aw- dropping borders . Be forewarned that visiting Far Reaches Farm can be a little heart wrenching because many of the most sought-after plants sell out soon after they become available. The details. Far Reaches Farm sells plants via its online catalog. Plants are also available at the nursery, which is open from spring into fall— from 10 a.m. to 4 p.m., Thursday through Saturday. Plants ordered online can be picked up year- round by appointment between 10 a.m. and 3 p.m. on weekdays. More information, including dates and locations of off- site plant sales, can be found on the nursery’s website, farreachesfarm.com. Chimacum Woods If you’re heading west to the Olympic Peninsula from the Kingston or Bainbridge Island ferries, take a left, just a few miles after crossing the Hood Canal Bridge, to wend your way to rhodo- dendron nursery Chimacum Woods. Shrouded in a forest setting about four miles south of State Route 104, the nine-acre nursery is owned by Bob Zimmermann and Beth Orling. The story of Chimacum Woods. The nursery was started by Bob in 1976, and Beth joined the business after their marriage in 2001. Bob and Nesting killdeer (here, an adult is sheltering four chicks) prevent expansion of entry garden at Far Reaches Farm. (Photo by David Gluckman) 4 Washington Park Arboretum Bulletin Beth met in grade school and stayed in touch through college, then lost contact for 38 years. Neither had strong horticultural roots; Bob was an English major in college, while Beth majored in German. When Bob bought his first house during graduate school, he also acquired his first rhody, (a hybrid named ‘Elizabeth’) and recalled that his father had grown rhododendrons in New Jersey. After that, he had purchased a “Sunset” book on rhododendrons, the last chapter of which was on propagation. Bob took a cutting from a rhodo- dendron growing at the local library, turned a pie tin upside down over the pilot light on his gas stove, and put the cutting in a pot covered with a plastic bag. (The book said that bottom heat and high humidity were recommended for propagating rhodies.) Hewas careful to move the pot every time he used the stove. The cutting rooted (it turned out to be Rhododendron ‘Fragrantissimum’), and Bob’s passion for the genus was ignited. Bob says his formal education in horticul- ture was by trial and error in the school of hard knocks— with an emphasis on error, report- edly having made every mistake in the book. He says he’s still learning and has two large piles of dumped substrate from dead plants at the nursery to prove it. The turning point for Chimacum Woods was in 1982, when China eased travel restrictions and Bob began to get wild- collected rhododendron seed. Since then, Chimacum Woods has focused TOP: The long, narrow, lanceolate leaves and pink-white flowers of Rhododendron makinoi — for sale at Chimacum Woods. (Photo by Steve Law/Wikimedia Commons) CENTER: Beth Orling and Bob Zimmermann of Chimacum Woods with Rhododendron luteum, which was grown from wild-collected seed from Turkey. (Photo by Chimacum Woods) BOTTOM: Fragrant white flowers of summer-flowerin Rhododendron auriculatum at Chimacum Woods. (Photo by Chimacum Woods) Summer 2016 5 almost exclusively on species plants grown from seed, either wild collected or carefully hand pollinated. From the seed cups, the plants go into two-inch bands, then four-inch pots, then one-gallon contain- ers—and finally into two-gallon containers to grow out their roots for sale the following year. The entire process takes five to six years. For Bob and Beth, species rhododendrons are about foliage, and flowers are just a bonus. Bob has been on numerous seed-hunting expeditions. In 1997, he explored southwest Tibet with rhododendron specialist Kenneth Cox of Glendoick Gardens in Perth, Scotland. They were the first westerners to visit the area in 5° years and brought back Rhododendron lanatoides, a species new to cultivation in the West. Subsequent trips included ones to Yunnan Province in 2000 and 2001, and another to Sichuan Province in 2009. He also led his own trips in 2013 and 2015. Bob says the trips, for him, are about one -third botanical, one -third cultural (they are always based in tribal areas) , one-third political (he was arrested in Tibet), and one-third spiritual. (Because his days start at 6 a.m. and end at midnight, he claims there are enough hours in one day for an extra third!) On his best day, Bob saw 43 different species of rhododendrons. His longest hike, in 2000, was 20 miles in one day, with 65 00 feet of elevation change; the second longest was in 2015, with 16 miles and 5200 feet of elevation change. The plants. You can purchase rhododendrons at Chimacum Woods, and you can also stroll paths through an extensive display garden. In summer, the garden is a study in what species rhododendrons look like year round— with striking leaves that don’t need flowers to be appealing and elegant shapes that transcend the stereotypical rounded balls of many plants in the trade— not to mention the unattractive, leggy shapes that many rhodys assume once they have outgrown their sites. Chimacum Woods is a working garden and experimentation is ongoing. Rhododendrons can be found in hanging baskets. (Some of them, after all, are epiphytes.) There are also some species that bloom in July, August or September. Most of these have white flowers, and all are fragrant. Rhododendron auriculatum is a good example. Bob and Beth are always in propagation mode— growing seeds, transplanting, making cuttings, etc.— and they are enthusiastic about sharing their knowledge. The details. Visitors to Chimacum Woods are always welcome by appointment. Along with extensive plant descriptions and photos, the TOP: Hoophouse at The Desert Northwest contains a treasure trove of exotic species. (Photo by The Desert Northwest) INSET: Ian Barclay of The Desert Northwest in Sequim. (Photo by The Desert Northwest) OPPOSITE PACE: Winter flowers of Crevillea victoriae ‘Murray Valley Queen’. (Photo by Janine Anderson) 6 - Washington Park Arboretum Bulletin nursery’s website (chimacumwoods.com) lists weekends when the nursery is open to the public; Puget Sound garden centers that carry its plants; and also dates and locations of local plant sales, where plants from the nursery are featured. The Desert Northwest Located in Sequim, Washington— just south of Highway 101— The Desert Northwestis ownedby Ian Barclay and specializes in drought -tolerant and rare plants. The story of The Desert Northwest. Ian’s inter- est in plants developed while in high school in Olympia, Washington. He joined the school’s horticulture club and quickly filled a hobby greenhouse with rare and unusual plants collected at specialty nurseries. As a senior, Ian took horticulture as an elective, but most of his learning was hands-on at home. Ian entered Washington State University as a music major but ended up with a degree in ornamental horticulture. Despite his creden- tials, most of what he knows came about through trial and error and experimentation. Because he experimented at his parents’ property while in college, he developed an interest in plants that would require very little care during the months that he was away. What survived were generally plants that were watered only once after planting. Eucalyptus and other Australian plants thrived. At one time, Ian had over 100 species of Eucalyptus. About 20 to 25 °f these survived the hard winters of 2008 to 2010. Ian still likes Eucalyptus, although he no longer offers many for sale. He’s partial to plants from Australia, New Zealand, Chile, South Africa, California, the American Southwest, the Mediterranean region and, to some extent, Mexico. He’s not particularly smitten with thirsty Asiatic flora, but— of course— there are excep- tions. His favorite genera include Grevillea, Eucalyptus, Olearia, Leptospermum, Opuntia, Agave, Arctostaphylos, Quercus (especially the evergreen oaks), Podocarpus and Delosperma. Ian went through a bamboo phase and, at one point, had about 100 different kinds of bamboo. He is now down to 6 O or so and has decided to continue to maintain them only as a hobby because they don’t fit the water-wise theme of the nursery. The plants. The Desert Northwest sells plants from each of Ian’s favorite genera. For example, there’s New Zealand native Olearia ilicifolia, which has dark stems and crinkly, gray, holly- like leaves; the Australian native Leptospermum lanigerum, which has small leaves that are aromatic when bruised; and at least seven varieties of Grevillea victoriae (royal grevillea) —including ‘Murray Valley Queen’, which, at four-by-four feet, is somewhat more compact than the straight species. Most of Ian’s plants are available by mail order. Plants in pots larger than one gallon must be picked up at the nursery. Ian also delivers plants throughout the region for a fee and/or minimum order. The details. Information about dates the nursery is open for visitors, along with plant sales in which Ian is participating, can be found on Ian’s blog (desertnw.wordpress.com). Conclusion Far Reaches Farm, Chimacum Woods and The Desert Northwest are three fascinating des- tinations for gardeners visiting the Olympic Peninsula during the summer. Each nursery offers unique and exotic plants from around the globe. The vast knowledge of their impassioned creators is shared enthusiastically with visitors, and you will return home all the richer for having visited them. Janine Anderson, CPH, is an award-winning Pacific Northwest-based landscape designer (www.anderson-design.net), garden writer, speaker, and member of the “Bulletin” Editorial Board. Summer 2016 7 Rosa x cantabrigiensis ‘Red Wing’ blooming in Crabapple Meadow in June. Hidden Treasures of the Arboretum Rosa x cantabrigiensis ‘Red Wing ou may not think of the Arboretum— with its mossy groves of conifers — as a good plac e to s e ek out ro s e s , but you ’d be mistaken. The University of Washington’s collection features more than 15 O individual plants, representing 30 species, and an addi- tional 35 cultivars and hybrids. A large number of these roses are growing in the Arboretum proper and arrived here between 1947 and i960, under the auspices of then-director Brian Mulligan. One, in particular, stands out for its year-round interest: Rosa x cantabrigiensis ‘RedWing’. Rosa x cantabrigiensis was a chance seedling found in the Cambridge University Botanic Garden in the late 1930s by rose geneticist 8 Washington Park Arboretum Bulletin Charles Chamberlain Hurst. Hurst worked there from 192,2, to 1947, trying to disentangle the complicated genetics of garden roses, and he created a few beautiful hybrids himself. Rosa x cantabrigiensis is the best-known and most widely used of his Cambridge roses. It was awarded the Royal Horticultural Society’s Award of Garden Merit in 1994. A cross between Rosa hugonis, the golden rose of China, and R. sericea, the silky rose, it possesses the lovely fern-like foliage of both parent species. Its single, large, gently fragrant flowers are a primrose yellow— somewhere between the white of R. sericea and the golden yellow of R. hugonis. They appear as early as mid-May and are followed by handsome orange - red hips in late summer. Two specimens of this rose grow in the Arboretum on the southeast side of Crabapple Meadow. Growing with them is a cultivar of mysterious origin called ‘Red Wing’. The winged, fiery-red thorns on the new canes— an attribute inherited from the silky rose— make this rose stand out from the straight Rosa x cantabrigiensis . The Arboretum received five six-inch plants ofR. x cantabrigiensis ‘ Red Wing’ from the Arnold Arboretum in October of 1958. They were grown in the nursery for a decade before being planted out in the Arboretum. One specimen, which was planted along the road to Foster Island, was lost to the construction of the Evergreen Point Bridge in the early 1960s; another nearby specimen failed to establish and succumbed to drought. According to UW Botanic Gardens Curator of Living Collections Ray Larson, two specimens were planted in the old Rose section north of the Arboretum, in beds facing Lake Washington Boulevard. But these beds were destroyed, along with many others in the late 1960s, during the construction of the RH Thompson ramps. The records say that, prior to the construction, one of the plants was moved back to the nursery (which back then included all of current-day Crabapple Meadow), and the other was planted in the lath house (remnants of which can still be seen behind the Big Greenhouse). It’s unclear what happened to these plants since. But we do know that one still thrives along the service road that runs south from the Graham Visitor Center along the Broadmoor fence. It was planted there in 1967, when it was only four-and- a-half-feet tall. It is now a dense stand of old and new canes 10 feet wide and tall. When in bloom, it’s covered with amass of lovely yellow flowers. If you wander down the service road past the greenhouse and the beehives, you will soon reach the crabapple collection, where you’ll find numerous large roses. Continue on the road until you’re almost beyond the meadow, and you won’t be able to miss the large red thorns of R. x cantabrigiensis ‘RedWing’. Daniel Mount is an estate gardener, garden writer and member of the “Bulletin” Editorial Board. He lives on a small farm in the Snoqualmie Valley. Read more of his reflections on plants and gardening atwww.mountgardens.com. Summer 2016 9 Blue orchard mason, Osmia lignaria. (Photo by USCS Bee wentory and Monitoring Lab / X Wikimedia Commons) Getting to Know Our Native Bees O 'MT f. ■ mm f \ ' . . ’ * . A * • • ^ ■ jL|j ' ! ' jHH « it By Hillary Sardinas ith summer here, gardens are buzzing with pollinators— and not only the honey bees. The European honey bee is just one of more than 20,000 bee species worldwide. Honey bees, brought to America by settlers, only reached the West Coast in the l86os. Before that wild, unmanaged bees provided most of the polli- nation of wildflowers and crops. Native bees are still the most important pollinators of wild plants, helping to maintain ecosystem diversity. In addition, bees help feed the world: One out of every three bites of food we eat needs a polli- nator to reproduce. Native bees play a large role in crop pollination, and they are often better pollinators than honey bees, spending more time on each flower and therefore helping to transfer more pollen. Most bee diversity is concentrated in Mediterranean environments, however the Pacific Northwest also hosts numerous species. The vast majority of bees are solitary, meaning TO they don’t form complex colonies with divisions of labor, like honey bees. Although social bumble bees nest in cavities, solitary wild bees either excavate nests in the ground, or find hollow stems to occupy. The rainy environment in the Pacific Northwest makes the latter nesting strategy much more attractive, as plant stems are less likely than soil to get inundated. Because most native bees are solitary, they don’t have a hive to protect and are therefore much less likely to sting than honey bees. In fact, you really have to get a native bee mad to provoke it into stinging you. Causes of Bee Decline Unfortunately, both native bees and honey bees are currently declining due to a number of threats. Habitat loss is one of the major drivers of biodiversity loss worldwide. Even remnant habi- tat fragments are losing value due to the spread of invasive plants. The invasives compete with the native plant species most wild bees rely on for pollen and nectar. Disease spread is another major issue facing bee populations. Managed Washington Park Arboretum Bulletin bees, like bumble bees used for tomato pollina- tion, spread disease to native bumble bees. Many bumble bee species that were once widespread have disappeared throughout most of their range. The western bumble bee Bombus occidentalis used to be the most common species west of the Mississippi, but is now rarely seen. Another spe- cies with a more limited range, Franklin’s bumble bee Bombus franklinii, hasn’t been recorded since 2006, despite extensive searches in its former Southern Oregon range. How You Can Help You can help with bee conservation by plant- ing flowering plants in your yard for continuous, year-round bloom. Focus on native species because ornamental plants, while showy, often no longer produce the pollen and nectar bees rely on. Bees also need nest sites, either undis- turbed bare soil or pithy- stemmed plants (like raspberries). See the “Native Plants for Native Bees” on page 13 for some recommendations. More extensive plant lists for regional pollina- tors, as well as recommended nurseries and other resources, can be found at: www.xerces. org/ pollinators -pacific - northwe st-region/. Make sure that the plants you purchase weren’t treated with systemic pesticides like neonicotinoids. Systemic pesticides can be expressed in pollen and nectar, making them toxic to bees. In addition, it is important to avoid spraying any blooming plants with pesticides or herbicides, as these can be harmful to bees and other pollinating insects like syrphid flies. Learn more by exploring www.xerces.org/ pollinator- conservation/. Major Bee Groups in the Pacific Northwes Of course, when you’re trying to contrib- ute to a conservation effort, it can help to know a little bit about what it is you’re trying to con- serve. Below are profiles of some of the major bee groups in our region. Next time you’re out in your garden, see how many of these groups you can identify. Bumble Bees ( Bombus ) Life History: Bumble bees are some of the most important pollinators. They are active from early spring, when queens first emerge and search for food to start their colony, until late fall. Bumble bees have the ability to buzz pollinate, or vibrate a flower at a frequency that causes pollen other- wise locked within a flower to explode onto the bee. Bees that can’t buzz pollinate are ineffec- tive pollinators of plants that require it, such The Xerces Society for Invertebrate Conservation Robert Michael Pyle started the Xerces Society in 1971 to raise awareness about invertebrate conserva- tion. Named after the extinctXerces Blue butterfly, which used to live on the sand dunes of San Francisco, the Xerces Society continues to educate and advocate for critically important but often unseen species. On-Farm Conservation: The Xerces Society’s Pollinator Program has worked with farmers across the U.S. to create on-farm, flower-rich habitats. It has supported the creation of more than 250)00° acres of pollinator meadows and hedgerows. These areas not only support crop pollinators, but also provide habitat to natural enemies of crop pests. The Pollinator Program has offered trainings, field days and short courses to farmers in ah 5 O states. On-farm habitat benefits both pollinators and farmers, who see increased crop pollination and yields. Endangered Species Conservation: The Xerces Society also works to monitor populations of imperiled pollinators. Project Bumble Bee combines science and advocacy to engage citizens, landowners and government agencies in the protection of declining bumble bee species. You, too, can get involved in efforts to track bumble bee species by joining Bumble Bee Watch, a citizen science initiative that helps researchers track species remotely. You can upload photos of bumble bees that will be identified by an expert atwww.bumblebeewatch.org/. Summer 2016 11 Yellow-faced bumble bee, Bombus vosnesenskii. (Photo by Kevin Cole/ Wikimedia Commons) Female snowy andrena, Andrena nivalis. (© Michael Veit 2010/ www. discoverlife.org) as tomatoes. Bumble bees are also generalists, meaning that they visit a number of different plant species instead of focusing on one or a few. They also have large ranges, enabling them to polli- nate plants over great distances. Bumble bees are keystone species in many ecosystems— meaning that a lot of other species in these systems depend on them. Description: Bumble bees are easy to identify, with their large, fuzzy bodies and iconic black and yellow banding. Some species of bumble bee have white or orange markings as well. Like honeybees, bumble bees carry moistened balls of pollen on their hind legs. Common PNW species: Black tail bumble bee, Bombus melanopygus ; fuzzy-horned bumble bee, Bombus mixtus ; yellow-faced bumble bee, Bombus vosnesenskii-, California bumble bee, Bombus califomica. Sweat Bees [Lasioglossum and Halictus) Life History: Sweat bees got their name because some species collect salt from animal sweat, including from humans. Sweat bees are small and dark; they don’t have the typically black and yellow coloring we associate with bees. For these reasons, sweat bees are often confused with flies. Because they are so small, they polli- nate by climbing deep into flowers and spending a lot of time drinking nectar and collecting pollen. They are quasi -social, with mothers and daughters living together but not splitting labor or suppressing one another’s reproduction. (In short, there’s no queen.) They are often one of the most common bee species in urban and agricultural environments. Description: Sweat bees are usually black or dark-metallic grey. Some species have pale, hairy strips on their abdomen. They carry dry pollen on their hind legs. Common PNW species: small sweat bee, Halictus tripartitus ; medium sweat bee, Halictus ligatus ; tiny sweat bee, Lasioglossum species. Mining Bees ( Andrena ) Life History: Mining bees excavate nests under- ground, hence the common name. They are one of the main blueberry pollinators besides bumble bees, often nesting at the base of blueberry plants. (One native species, Andrena astragali, is a specialist pollinator of the death camas— Zigadenus species— and has the unfortunate name death camas bee.) They also have been known to nest in lawns. Mining bees are solitary, with one female creating a few nests during her lifetime, which often lasts just four to eight weeks. Each nest in the dirt contains approxi- mately five cells, or chambers, provisioned with enough pollen for a single bee larvae. The female bee lays one egg per cell, then caps the cell with mud; she never sees her offspring. After an egg hatches, the larva consumes all the pollen, then metamorphoses into an adult bee. It spends the rest of the year and winter in diapause (a period of suspended development) underground, waiting for the right seasonal cues (temperature and moisture), which let it know that it’s time to emerge to pollinate and reproduce. 12 Washington Park Arboretum Bulletin Description: Mining bees often have fuzzy orange or blond thoraxes (midsections) and dark abdomens with light stripes. They carry their pollen dry on their hind legs, which makes them look like they are wearing chaps. Common PNW species: Death camas bee, Andrena astragali-, snowy adrena, Andrena nivalis; Andrena evoluta. Leafcutter Bees ( Megachile ) Life History: Leafcutter bees are aptly named: They cut sections of leaves or petals to create cell divisions within their nests. Leafcutter bees have large mandibles (oral appendages used for cutting) and wide heads to help with their task of snipping pieces of plant. Leafcutter bees nest aboveground in holes in wood. Because of the tight nesting space, instead of carrying pollen on their legs, they carry it under their abdomen. Another name for leafcutter bees is “hairy-belly bees,” which refers to the specialized hairs, or “scopa,” on their underside. When they forage on flowers, leafcutter bees often lift their abdomen up, preventing it from wiping the pollen away on the flower. This posture distinguishes them from other bee species. Though leafcutters can cause superficial damage to some plants in the garden, they more than make up for it by being produc- tive summer pollinators. (If they are targeting a prized rose or other plant, you can protect it temporarily with row cover cloth until the bees find something new to take pieces from.) Description: Leafcutter bees are often more squat-looking than other bee species. They carry Here are some handsome Northwest native plants— listed in order of bloom time— that provide good food and habitat for native bees. For more suggestions, visit www.xerces.org/pollinators-pacific- northwe st - region/. Perennials Bigleaf lupine ( Lupinus polyphyllus) Slender clarkia ( Clarkia gracilis) Selfheal ( Prunella vulgaris ssp. lanceolata) Canada goldenrod ( Solidago canadensis) Hall’s aster ( Sym phytotrichum hallii) Shrubs Oregon grape ( Mahonia aquifolium) Blueblossom ( Ceanothus thyrsifloru ) Cascara ( Rhamnus purshiana) Nootka rose ( Rosa nutkana) Salal ( Caultheria shallon) Oceanspray ( Holodiscus discolor) Coyotebrush (Baccharis pilularis) their pollen under their abdomens, which are usually black with pale bands of hair. Common PNW species: western leafcutter bee, Megachile perihirta; silver-tailed petal-cutter beer, Megachile montivaga. Mason Bees ( Osmia ) Life History: Mason bees are named for the way they use mud as a building material to create cell divisions in their nests. Providing access to mud can help support populations of wild mason bees. Mason bees are solitary, and they make Summer 2016 r 13