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The horticulture program provides researched-based urban landscape and garden classes. The office offers a free Plant Diagnostic Clinic from May thru September, operated with the help of Idaho Master Gardeners to answers clientele questions. PNW Pest Alerts for landscape and garden in the Treasure Valley are generated out of this office. Each year January thru April a new group of master gardeners is provided training.

Put some color into your landscape by supporting the Idaho Master Gardeners in Canyon County.

Thank you to everyone who supported are 2023 Spring Plant Sale.  Watch for upcoming information on future sales.



The University of Idaho Extension's Idaho Master Gardener Program consists of dedicated volunteers who provide gardening and horticulture information to Canyon County residents through plant clinic, classes, community outreach, demonstration gardens and other activities.

Through the Idaho Master Gardener training session, you will gain knowledge in soils, basic botany, disease diagnosis, insects, weed identification and management, lawn care, landscape shrubs and trees, vegetables, herbs and fruits.

It's about sharing your passion and knowledge of gardening with your community. It's about empowering the community to tackle their landscaping and gardening challenges by providing them with research-based solutions for a more sustainable life. 

Idaho Master Gardener Program website


Plant clinics are designed to help address concerns in gardens or landscapes. Idaho Master Gardeners are available Monday afternoon, 1-4 p.m.; Tuesday morning, 9 a.m. to noon; Wednesday afternoon, 1-4 p.m., May through September.

Samples can be submitted Monday through Friday, 8 a.m. to 5 p.m. Samples will be evaluated during Plant Clinic, and you will be contacted for more information and/or recommendations.

  • Submit several plant parts with varying degrees of severity.
  • Include one healthy sample, if possible.
  • If a branch is partially affected, bring in a section where it changes from healthy to unhealthy.
  • Wrap all plants in a dry paper towel and place in a sealable bag.

Photo Submission Guidelines

Photos of plants can also be emailed to Canyon County Idaho Master Gardener. Use the recommendations below.

  • Include one close-up picture
  • Include one entire plant picture
  • Include one picture which shows the plant and the surrounding landscape
  • Additional pictures can be included as needed
  • Take photo with indirect light when possible

Submission Forms

To help with the diagnostic process please select the document below which best matches your request. Compete page one of the document and submit to

Tree Samples

  • Bring a branch approximately 12-18 inches long showing the progression of the problem. If the problem is on the trunk, bring or submit a clear picture following photo submission guideline.

Turf Samples

  • Bring a 12 inches square section from the problem area, showing a portion of the healthy and unhealthy conditions, including 2-3 inches of soil.

Weed Samples

  • Bring whole plant(s) with root system intact. Plants with flowers or seed heads are easier to identify.

Insect Samples

  • Submit several specimens, when possible.
  • Submitted specimen(s) should be in a closed container.
  • Clear photos may be submitted to Canyon County Idaho Master Gardener. Include clear images of the insect from top, bottom and side when possible. Include a penny next to the insect for scale.

This is a free service, just another way the UI Extension gives back to the community.

Cost of standard soil fertility test is $55. Local lab resources are Western Laboratories in Parma or University of Idaho Analytical Science Laboratory in Moscow. Please call the office for more information.

Follow our Master Gardeners on Facebook and Instagram or read our Idaho Growin' blog.


University of Idaho Extension, Canyon County

Mailing Address:
501 Main St
Caldwell, ID 83605

Phone: 208-459-6003

Fax: 208-454-6349



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