UC Master Gardeners of San Mateo & San Francisco
University of California
UC Master Gardeners of San Mateo & San Francisco

Advice to Grow By... Ask a Master Gardener

UC Master Gardeners are certified UC volunteers from San Mateo and San Francisco Counties. Our Garden Helpline is available to assist home gardeners with questions about gardening and pest management. Volunteer UC Master Gardeners staff the Helpline on Mondays and Thursdays from 9am - 4pm. (We are closed on holidays.)

Call us: 650-276-7430 

Email us: mgsmsf@ucanr.edu

For fastest service, please provide as much information as you can in your email:


City of Residence


Phone, Best time to call

Description of Problem/Question

For plant or pest problems, please attach photo(s).

  • For plant problems, include:
    • what the damage looks like
    • when symptoms first appeared
    • where is the plant located
    • age of plant
  • For pest problems, include:
    • what damage is occurring
    • extent of the damage (how widely spread)
    • when symptoms first appeared
  • What care has the plant received?
    • Irrigation: Drip/Sprinkler/Hand/Flood. How often?  How long?
    • Fertlizer: What type? How often? Last applied?
    • Chemical applications, if any (herbicides and/or pesticides)

Visit us: You are welcome to visit one of our offices to consult with us during Helpline hours. Please bring your plant or pest problems with you in a sealed bag or container.


Mondays 9-am - 4pm Thursdays 9am - 4pm
Elkus Ranch
1500 Purisima Creek Road
Half Moon Bay

Veterans Memorial Senior Center
1455 Madison Ave.
Redwood City 

 We also hold regular Plant Clinics in various places in San Mateo and San Francisco Counties. Check our Calendar for locations and dates.

Webmaster Email: kmstewart@ucanr.edu