Print Page   |   Sign In   |   Join
Certified Professional Horticulturist
Share |


 What is a Certified Professional Horticulturist & How Can They Help




Horticultural Expertise


The designation, Certified Professional Horticulturist, represents at the minimum: 
2000 hours of professional experience; proven knowledge

of horticultural principles; 
and a commitment to
continuing education.

Certified Professional Horticulturists have experience, education and knowledge
of horticulture, much like
other experts in their fields.

A Valuable Resource


A Certified Professional Horticulturist can help
solve garden challenges
from pruning to plant selection and ensuring garden success.

Certified Professional Horticulturists offer services in a variety of areas including garden design, garden coaching, container design, fine pruning, landscape maintenance & installation,
and more.

Find a Certified Professional Horticulturist

You can find a Certified Professional Horticulturist on staff at your local garden center, retail nursery, or landscape business. And, they are waiting to help with your gardening success!

Click here to find a WSNLA member business with a Certified Professional Horticulturist on staff.




Become a Certified Professional Horticulturist 

Helpful Links

Certified Professional Horticulturist Program Info

CPH Credit Policy

Register for an Upcoming Certified Professional Horticulturist Plant ID, Preview Exam or Exam

Study Materials
Registration for Exam
& Prep Courses

CPH Plant List


Why Hire a CPH 
- Who we are &
how we can help

 - WestSound Magazine Article
Find a CPH

Contact Us

Holly Osborne, CPH

The Certified Professional Horticulturist (CPH) program is designed for the mastery of basic horticulture and continuing education to build on your knowledge and skills. As a Certified Professional Horticulturist, you’ll join an outstanding group of peers who’ve chosen to enhance their stature and attain this high level of professional excellence. Simply follow these five steps:


Step 1: Certified Professional Horticulturist Study Materials

Sustainable Gardening is the primary horticultural text covering basics like botany, soils, landscape practices, and more. It is purchased through OSU cooperative extension. Additional study materials include a Certified Professional Horticulturist Plant List, Plant Nomenclature, and Info Sheet. Follow the links below to obtain Certified Professional Horticulturist study materials. 


Step 2: Pass the Certified Professional Horticulturist Exam

A written exam tests your skills and knowledge as a horticultural professional based on study materials and practical applications. A core element of the Certified Professional Horticulturist exam is plant identification. The Certified Professional Horticulturist plant list, developed by industry practitioners and educators, includes 282 plants found in pacific northwest landscapes that a professional horticulturist show be able to identify. The test is administered twice yearly by the WSNLA Certification Board, in March and October. Click here for upcoming exam dates.

Step 3: Demonstrate your work experience

You must prove the equivalent of one year of work experience (2000 hours) with a licensed nursery, landscape contractor or WSNLA-approved business or institution.

Step 4: Fill out the paper work

After passing the exam, file for certification and provide work experience statements from your employer. Students are allowed two years to obtain necessary work experience and receive a Letter of Qualification until they qualify for full Certified Professional Horticulturist certification. Congratulations, you are now a Certified Professional Horticulturist!



Step 5: Maintain your Certified Professional Horticulturist certification

As a Certified Professional Horticulturist, your continued education is required to maintain and update your credentials and skills. There is an annual renewal fee due each year. Every three years, your certification is renewed upon completion of 15 Continuing Education Credits. It’s easy: every hour spent equals one credit. Fifteen hours in three years is all it takes. WSNLA produces a variety of qualifying seminars each year. Credit is also given for seminars from relevant professional organizations or accredited institutions and teaching horticulture. You’ll receive complete information about maintaining certification when you enter the program.

About the Certified Professional Horticulturist Certification



In 1978, WSNLA created a two-pronged professional certification program that was known as the Washington Certified Nurseryman or Washington Certified Landscaper. In 2005, WSNLA revamped and upgraded the certification program and renamed the designation as Certified Professional Horticulturist. With nearly 400 Certified Professional Horticulturists, the Certified Professional Horticulturist program is the largest community of state certifications serving professional horticulturists in Washington State.

If you're interested in becoming a Certified Professional Horticulturist, please contact WA State Nursery & Landscape Association at (800) 672-7711 or



Association Management Software Powered by YourMembership  ::  Legal