530-458-3190 margoc@frontiernet.net

About Our Speakers

Suzanne Bontempo

Suzanne is an experienced horticulturist, IPM Advocate, urban garden educator and fine gardener. She has served in retail nursery management, and is a landscape designer. She has advanced training in integrated pest management, business management, urban composting, vermiculture, greywater systems and stormwater pollution prevention. Broad experience includes running her own landscape business, and project managing. Collectively, with the IPM Advocate Program, she received the 2013 IPM Innovators award.

Current passions include teaching folks about gardening without pesticides. As a representative of the Our Water Our World program in the San Francisco Bay Area, she actively mentors and lectures various groups about pesticide runoff and non-toxic alternatives to support integrated pest management around their homes & garden. Philosophies are that of Deep Ecology and Biodynamic practices.


Jim Borneman

Jim Borneman is the Founder of Ewing Education Services at Ewing Irrigation and Landscape Supply.
Jim attended Chico State College and has a degree in Business Management from St. Mary’s College of California. Jim is a Licensed Texas Irrigator LN 7979 and has held certifications as a Designer, Contractor, and Irrigation Auditor with the Irrigation Association.

After a sabbatical in 2012, Jim returned to Ewing to continue his efforts in curriculum development with a greater emphasis on teaching as opposed to the many administrative responsibilities associated with leading Ewing’s Education Department. 2019 marked Jim’s 45th year in the landscape industry. During this time Jim has worked in a variety of sales and operations positions with manufacturers and distributors. Prior to coming to Ewing in 1994 he was the Director of Education for the Irrigation Association.

Industry education has been a focus and a passion for Jim since the late 1970’s and over the years he has trained tens of thousands of Landscape Professionals. Jim joins us with a passion for water conservation that is a natural part of his legacy as a fourth generation Californian.



Dr. Larry Costello

Larry has worked in the green industry in California for over 33 years.  After a 30-year career with the University of California, he retired Emeritus in 2011 and started the nursery. While with UC, he conducted a research and education program focused on tree management practices and co-authored Oaks in the Urban Landscape: Selection, Care and Preservation (2011). He is a member of the International Society of Arboriculture (Western Chapter) and the San Francisco Urban Forestry Council. He is owner of Oracle Oaks Nursery in Hopland, CA.

Aaron Dillon

Aaron Driggs Dillon from Four Winds Growers is a Fourth Generation Citrus Nurseryman.  He is proud to carry on his family’s tradition of providing their customers with high quality citrus trees for use in any setting. Since 2002, Aaron has helped to expand Four Winds Growers offerings to include a wider range of edible fruit trees and bushes that can be used as the perfect base for creating sustainable and productive landscapes.

Aaron has worked on the development of Four Winds Growers newest growing grounds in Watsonville, which features a 100,000 sq ft state of the art propagation facility for citrus nursery stock production. Aaron currently lives at the nursery in Watsonville, with his wife Carrie and their daughters Olivia and Amelie.

 He serves on numerous professional boards:

  • California Citrus Nursery Society (CCNS)
  • Education Committee of the California Citrus Nursery Advisory Board (CCNAB)
  • Education Committee of the California Association of Nurseries and Garden Centers (CANGC)
  • National Clean Plant Network Citrus Sub Group

(The NCPN provides high quality asexually propagated plant material free of targeted plant pathogens and pests that cause economic loss to protect the environment and ensure the global competitiveness of specialty crop producers.)

Christina Delgado

Christina leads Talent Acquisition at Hunter Industries, connecting and attracting top talent on a global level with the organization. She is a San Diego native and has her Bachelor’s Degree from California State University San Marcos in Communications. With over 10 years of recruiting experience, primarily within the manufacturing industry, her hiring portfolio includes a wide range of professionals in manufacturing, sales, engineering, technical, commercial, corporate and executive management.

Christina first began her career in the staffing industry with Aerotek Staffing and then joined one of her clients as an internal recruiter for Zodiac Pool Systems (Fluidra), where she found her passion for connecting top talent to help build culture. She loves impacting culture and contributing to building cohesive teams to achieve organizational goals.

Julie Saare-Edmonds

Julie is a Senior Environmental Scientist with the CA Department of Water Resources specializing in landscape water use efficiency and green building for almost 19 years.  She has been involved in two updates of the Model Water Efficient Landscape Ordinance, written publications, and helped design an award winning landscape exhibit for the California State Fair.

She was a member of the ASABE/ICC 802-2014 Landscape Irrigation Sprinkler and Emitter Standard and the Cal Fire Urban Forestry Advisory Committee. Currently she is working with a large stakeholder group on an upcoming update of MWELO. She is QWEL certified and has passed the CLCA WMCP exam. She has degrees in Biological Conservation and Horticulture. Julie is also an UCCE Master Gardener.