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Washington State University

Become A Master Gardener

Program Contact: Sarah Moore, KCMG Program Coordinator
206-543-0943 •

Becoming A Master Gardener

For all email communication regarding the Master Gardener training program in King County, please use this email:

The application window for the 2023 class closed October 31, 2022. Applications for the 2024 class will open in September 2023.

Training to become a Master Gardener volunteer uses a blended learning model, including Zoom and in-person sessions, as well as a self-paced online horticulture course. The self-paced online course must be completed by March, including quizzes and final exam. More details below.

For 2023, classes will be held on 10 weekend dates, as follows:

  • In-person at Bellevue Botanical Garden, Aaron Education Center, 9am-3pm: Sunday, January 22, Saturday, February 11, & Sunday, March 12. We may split the class in half for some of these sessions, with half opting to attend in the morning, half in the afternoon.
  • Via Zoom: Saturdays, 9am-noon; January 28, February 4, 18 & 25, March 4.
  • In-person at our Master Gardener Demonstration Gardens, Saturday March 18 & 25, various location & time options.

Attendance at each of the sessions is required, as well as the successful completion of the self-paced horticulture course. The primary mode of communication outside of the classroom is via email ( Access to a printer is helpful but not required.

Applicable COVID protocols issued by state, WSU or local authorities will be strictly followed. Washington State Proclamation 21-14.5 requires that volunteers be fully vaccinated for COVID-19 to engage in volunteer work with institutes of higher education in Washington. Proof of vaccination will be required. More about the requirement and options for requesting an exemption can be found on our COVID-19 Resources page at



The application window for the 2023 class closed October 31, 2022. Applications for the 2024 class will open in September 2023.


Master Gardener Volunteer Program

Have you always wanted to learn more about gardening, have more of a science-based knowledge of gardening, meet new people and make a difference in the community? Then the WSU Master Gardener Program might be right for you.

The Master Gardener program was started by Washington State University Extension in King and Pierce counties in 1973 and has since been adopted in all 50 states and parts of Canada. Annually King County Master Gardeners donate over 44,000 hours of volunteer time at plant clinics, demonstration gardens, plant sales and other program activities.

Master Gardeners are community educators trained to work in partnership with Washington State University (WSU) Extension to educate the public and enhance the quality of life in communities by promoting science-based gardening practices. Master Gardeners provide gardening advice and education to the public at plant clinics, demonstration gardens and other outreach activities.

Becoming a WSU Master Gardener starts with training that combines (1) synchronous virtual training (2) classroom instruction, and (3) self-paced learning. Email and internet access are required. A smart phone is strongly recommended and is needed in order to fully participate in advising the public once classroom training is complete. Zoom and in-person sessions are primarily focused on becoming familiar with the many resources Master Gardeners use when advising the public, including online materials. Selected presentations from WSU and other local gardening experts on science-based gardening, plant problem diagnosis, and Integrated Pest Management (IPM) will provide practical application of key learning objectives.

The textbook for the online horticulture course is the WSU Master Gardener Manual, a 25-chapter, 640-page online publication that includes photographs and diagrams on such topics as basic botany, soil science, fruit and vegetable gardening, pruning, composting, landscape plants and entomology. Completion of this self-paced online course includes multiple-choice, open-book quizzes as well as an open-book final exam. A passing score on the multiple-choice quizzes is 80% or better. Time spent each week in the online portion of the class varies by student, but a minimum of 3+ hours should be expected.

Successful applicants to the Master Gardener program have an interest in and enthusiasm for volunteer work, talking to people about gardening, and continuous learning. Master Gardeners spend time answering a wide range of home gardening questions, especially at our plant clinics throughout the county. When asked for pest management recommendations, WSU Extension Master Gardeners are required to provide an integrated pest management approach which includes information about cultural, mechanical, biological, and chemical methods. Pesticide recommendations must be made from home and garden sections of relevant current WSU publications or other WSU-approved materials.

Applications are generally available in September for the following year’s class and are due electronically not later than October 31. Acceptance notifications will be sent in November. Each year we have more applicants than we can accommodate and do not accept late applications.

For the first year, successful trainees are considered “Interns” and must complete at least 40 hours of volunteer time by the end of September, including at least 15 hours volunteering at our plant clinics (each shift is 3-5 hours depending on clinic location), at least 10 hours volunteering at our demonstration gardens (shift length is flexible, generally 2-3 hours). After successful completion of the first-year requirements, “Interns” graduate to become certified Master Gardeners. Master Gardeners must be recertified each year. Recertification requirements include 25 volunteer hours (in King County Master Gardener program activities of their choice) and 10 hours of continuing education (in-person or online training on topics relevant to gardening in the Pacific Northwest).

Cost for the course in 2023 is $400, including $75 to WSU for the online course (which includes online access to the textbook/manual and quizzes). Cost in future years may vary. Please do NOT send payments with your application – tuition payment will be due upon your acceptance into the program. If cost is a financial hardship, a limited amount of financial assistance may be available. Background checks are also required for all Master Gardeners via a 3rd party service. Cost for the background check is $14.


When & Where in 2023:

First day of class is Sunday, January 22, at Bellevue Botanical Garden. Class will meet each weekend through March 25, via in-person or Zoom sessions. Sessions at Bellevue Botanical Garden and our Demonstration Gardens must be attended in person. Self-paced online course must be successfully completed by March.


$400 for 2022 due upon acceptance, payable by Credit Card only
$14 for background check, due upon acceptance, payable by Credit Card only

Technical Requirements:



Feature image by Jupiter Images


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