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Speaker Bios

Speaker Bios

Sarah Anderson

Sarah Anderson is the Branch Manager for Ewing Outdoor Supply in Burlington, WA. She has been with Ewing for 5 years.  Sarah grew up in Tucson, Arizona. She graduated with a Bachelors Degree in Horticulture from Brigham Young University.  Before working with Ewing, she was co-owner of Elite Landscaping with her husband, Hadley. She is a mother of two, and loves hiking with her family on the weekend.

Mary Lu Arpaia

Mary Lu Arpaia earned a Ph.D. from the University of California, Davis in Botany & Plant Sciences.  She is interested in the assessment of fruit quality and productivity as influenced both by cultural management and post-harvest handling of the product. Her research and extension activities reflect this interest in developing an information base on the continuum between the farmer and the consumer.  Her specialty is evaluation of pre-harvest and post-harvest factor on subtropical crop productivity and fruit quality, including root stock, cultivar, irrigation, pesticide and nutrition management strategies.  Areas of expertise include:  citrus, avocados, sub-tropical fruit, plants and their systems and plant biological efficiency and abiotic stresses affecting plants.

Dennis Bottemiller

Recently retired as the Nursery / Propagation manager at the Rhododendron Species Botanical Garden in Federal Way WA where he was responsible for cutting and seed production of species rhododendrons.  He obtained a degree in Production Horticulture from Washington State University in 1989 and was an intern at RSBG in 1987 which lead to his nursery position upon graduation.  Dennis took a seven year break from RSBG to manage collections and structures at the W. W. Seymour Conservatory in Tacoma WA.  This experience grounded him in conservatory culture and prepared him for the adventure of building and maintaining the Rutherford conservatory at the rhododendron garden which opened to the public in 2010 and where he holds his current position as part-time conservatory curator.


Linda Chalker-Scott Ph.D.

Dr. Linda Chalker-Scott has a Ph.D. in Horticulture from Oregon State

University and is an ISA certified arborist and an ASCA consulting arborist. She

is WSU’s Extension Urban Horticulturist and a Professor in the Department of

Horticulture. She conducts research in applied plant and soil sciences,

publishing the results in scientific articles and university Extension fact sheets.

She is currently the editor for WCISA’s Western Arborist magazine, the Journal

of NACAA, and Editor-in-Chief for Compost Science and Utilization. She is also

actively involved in enhancing the scientific literacy of her audiences by

teaching them how to assess the credibility of information from print and

online sources.

Linda also is the award-winning author of five books: the horticultural myth-

busting The Informed Gardener (2008) and The Informed Gardener Blooms

Again (2010) from the University of Washington Press and Sustainable

Landscapes and Gardens: Good Science – Practical Application (2009) from GFG

Publishing, Inc., and How Plants Work: The Science Behind the Amazing Things

Plants Do from Timber Press (2015). Her latest book is an update of Art

Kruckeberg’s Gardening with Native Plants of the Pacific Northwest from UW

Press (2019), which has won several national awards since its publication.

In 2018 Linda was featured in a video series – The Science of Gardening –

produced by The Great Courses. She also is one of the Garden Professors – a

group of academic colleagues who educate and entertain through their blog

and Facebook pages. Linda’s educational contributions to science-based

information have been recognized by such groups as Garden Communicators

International, the National Association of County Agricultural Agents, and the

International Society for Arboriculture.

"The Informed Gardener" webpage:

"The Garden Professors" blog:

"The Garden Professors" Facebook page -

"The Garden Professors" Facebook group -


Karen Chapman

Born in England, Karen grew up with a trowel in her hand.

After moving to the Pacific Northwest in 1996 she joined Molbak’s Garden & Home as a garden plant specialist before establishing Le Jardinet in 2006. Whilst initially specializing in custom container gardens, Karen now applies that same attention to detail by designing functional and artistic landscapes. Her designs have been featured in many prestigious publications, including Fine Gardening, Sunset, and Better Homes & Gardens.

She is co-author of two popular books on foliage-driven design: Gardening with Foliage First and Fine Foliage, and her latest book is Deer-Resistant Design.

When not designing gardens or writing about them, Karen is usually teaching in workshops around the country, as well as through a number of online courses. She has also leads garden tours both in her native England, the United States and this year also to South Africa.

Whether on the stage or the page, Karen’s aim is always to inspire, educate and share the fun of gardening with her audience.

Marlene Finley

A former wildland firefighter, retired forest manager, and is currently active Skagit County WSU Extension Master Gardener.  She lectures on all topics as a master gardener, but one of her primary focuses is FIREWISE, meaning that you need to assure that you have done “Wildfire preparedness for your home landscapes”.

Wes Gannaway

Wes Gannaway was born in Seattle and spent his childhood going from that city to the outskirts of Fortson, a mill town between Arlington and Darrington, back and forth between the country and the big city. After graduating from Ballard High School, Wes worked as an apprentice printer at the Seattle Times, then at Boeing. After serving in the Army, he worked in real estate then got a job with ARCO in Ferndale, retiring after 39 years. During this time, Wes studied geology at what was then Western Washington College.


Wes started doing research on the Whatcom County history in 1985 and gave his first presentation on the use of sandstone from the Roeder Quarry on Chuckanut Drive to construct many of the important buildings in the Northwest. Since then, Wes has done about 30 presentations for a number of organizations and taught classes for the Academy for Lifelong Learning at Western.


In 2010, Wes became the president of the Whatcom County Historical Society and is still in that position in 2023.

Don Hyatt (presenting via Zoom)

Donald W. Hyatt, or Don as most of his friends know him, earned his Master’s degree in Computer Science from Virginia Tech.  Don's Bachelor’s degree was in Horticulture with a double major in Biochemistry.  Having started his first garden at the family home in Northern Virginia when he was only three, Don claims to be a "plant person" at heart rather than a computer scientist.  Don is a member of the Potomac Valley chapter of the ARS. 

Don is recognized as a national authority on azaleas and rhododendrons and has served on the national boards of both the Azalea Society of America (ASA) and the American Rhododendron Society (ARS).  Don has received several bronze medals, a silver medal and the prestigious Gold Medal from the ARS as well as awards from the Azalea Society.  Don is a well sought after speaker on a number of topics.


Glen Jamieson Ph.D.

Glen has been an ARS member for 28 years as a member and past-President (four times) of the Mount Arrowsmith ARS Chapter, which is based in the Parksville-Qualicum Beach area on the south-east side of Vancouver Island, British Columbia, Canada. Glen and his wife Dorothy are keen gardeners, with a one-acre garden with many rhodos near the ocean. Glen has been championing vireya culture in ARS District 1 for the past two decades, having a substantial vireya collection, and strongly encourages others to become more familiar with this still relatively less cultured rhododendron group. Glen has explored for plants with other ARS members in Yunnan, China, and in Sikkim, India; has visited to date over 80 countries, including Borneo (Malaysia), New Zealand, Japan, Korea, Ecuador and Iceland, and frequently gives talks on his travels and plants. Professionally, Glen has a B.Sc. in Agriculture and a doctorate in Zoology (entomology), and is now a retired fisheries research scientist, having worked with Fisheries and Oceans Canada for over 30 years on both Canada's Atlantic and Pacific coasts. Glen took over as JARS editor in 2009 and has been the District 1 Director since 2020.


Doug Keough

Living in the small community of Clearview, WA, Doug had the fortunate opportunity to meet his neighbors, Loyd and Eddie Newcomb, and tour their beautiful rhododendron gardens.  Their enthusiasm and passion for rhododendrons was infectious, and they invited the Keoughs to join the ARS in 2003. Doug was the Pilchuck chapter president for 8 years, and is currently the newsletter editor.  Since retiring in 2011, Doug has more time to dedicate to propagation efforts.  He and his wife, Donna, have become full-time groundskeepers of their five acre Keyhole Gardens, where they grow many varieties of Japanese Maples, conifers, and hundreds of varieties of rhododendrons. Keyhole Gardens was featured on the private garden tour during the 2009 ARS convention in Everett, WA. Oh yes, and we still love Rhododendrons!!!

Juliana Medeiros, Ph.D.

Dr. Medeiros leads the plant ecophysiology lab at the Holden Arboretum and holds adjunct appointments in the Biology Departments at Case Western Reserve University and Kent State University. Her work investigates the impact of spatial and temporal variation in climate on plant physiology and anatomy, primarily focused on Rhododendron, but also including other woody plants.

In addition to her research activities, as a founding Co-Chair of the Rhododendron Research Network through the American Rhododendron Society Dr. Medeiros is also active in developing scientific programs for public audiences and building collaborative infrastructure that brings researchers together to foster new partnerships. She is committed to advancing and promoting research in the genus and is also actively involved in outreach programs for adults and K-12 students.  Juliana is a member of the Great Lakes Chapter of the ARS.

Dr. Medeiros holds a Bachelor of Science in Biology, a Master of Science in Biology and a Doctorate in Biology from the University of New Mexico.

For those of you who experienced the presentation by Dr. Medeiros in Parksville, BC, at the ARS Fall Western Regional Conference in September 2019 (“Drinking the Ocean Through A Straw: Rhododendron Strategies For Rapid Growth Under Water Limitation”), it’s obvious that she has a talent for communicating plant science in a very approachable way.

Jerry Rock

Jerry Rock is a person who loves rhododendrons.  He grows well over 3,000 on ten acres of wooded land.  He is a retired pharmacist, so he has knowledge of minerals and chemicals.  Over the years he has experimented with a variety of these items.  He has observed heat, cold, wind, and thermoclines that affect plants.  He has a PowerPoint presentation illustrating problems, solutions, and his observations.  He reads constantly regarding rhododendrons.  His library of information is extensive.  He recognizes that there may be more than one solution to a problem, and will welcome questions.  He is a very interesting person!  

Gisele Schoniger

Gisele “G” Schoniger is Manager and Organic Gardening Educator at Kellogg Garden Products. In her 35+ years in the Garden Industry and is the Organic Gardening Educator for Kellogg Garden Products.  She earned her degree in Ornamental Horticulture from California Polytechnic University in San Luis Obispo. She has owned an Interior-scape company, worked for the State Department of Agriculture, practiced as a horticultural therapist with senior citizens and launched an outstanding sales career by helping establish top-selling organic gardening products.   Gisele has accumulated a wide range of experience and knowledge that she shares in her programs.

Mike Stewart

Mike Stewart is a world famous rhododendron expert and speaker. He and his wife, Maria, owned the now closed Dover Nursery in Sandy, Oregon. Mike is an ARS past President and recipient of ARS’s Gold Medal. He is an excellent speaker and photographer. He is also President of the Rhododendron Species Botanical Garden. Mike and Maria have co-chaired many international conventions and western regional conferences for the ARS.

Yasmin Workman

After getting  the rhodie bug there was no stopping me. I met Elsie Waston, who became my mentor. The other mentors were Loyd and Eddie Newcombe plus Frank Fujioka. They taught and gave me a tremendous amount of knowledge on care and tips on growing, hybrid matching and foresight. Also to allow time to evaluate hybrids to judge or name.

Bob Zimmerman

Robert (Bob) Zimmermann fell in love with rhododendrons over fifty years ago. He began propagating them on his kitchen stove and now grows species rhododendrons from seed in his greenhouse at Chimacum Woods on Washington’s Olympic Peninsula. Some 300 species populate the collection in his garden, providing a reliable source of seed for the plants he makes available to gardeners in both the US and Canada. Bob has traveled with botanists, five times to China, once to Tibet, once to Japan, and, most recently, to Arunachal Pradesh in NE India.  Bob first joined the ARS as a member of the Portland Chapter in 1973 and is a past president of the Rhododendron Species Botanical Garden. He is a member of the ARS Seed Exchange grant committee.

Robert Fincham

Bob operated a mail order rare conifer nursery for 45 years and was a founding member and first president of the American Conifer Society. He moved to the Northwest in 1986 from Pennsylvania and has authored and self-published six books on cultivated conifers.

Mike Bones

Mike, tremendously gregarious with an infectious spirit, a lot of fun.  MIke is a Navy vet and former Oregon State park ranger, past Commander for the local American Legion post, and is a current board member who served more than 20 years as president of the Siuslaw Chapter of the American Rhododendron Society.  He’s won international recognition for his interest in rhododendrons by being awarded the International Silver Medal for his accomplishments in educating others about the flowers, and for his years of dedication and service to the Siuslaw and American Rhododendron Societies.

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