Colusa County
University of California
Colusa County

Master Gardeners


 Science based solutions for Colusa County's gardening communities.

The UCCE Master Gardeners of Colusa County volunteer's donated 720 hours and made 977 face to face contacts in 2015/16.


This is what we do!

Click here for a short video!


Native Bees and Bee Boxes


Saturday June 24, 10am to noon

100 Sunrise Blvd, conference room

  • Learn how to attract native bees to your garden.
  • What are native bees?
  • What do I plant to attract native bees?

Make a bee house to promote help promote bees.

$10 per person includes presentation, handouts and bee house. Deadline to pay is June 19.

Click here to pay.

Bee workshop



Colusa County Fair entries

Click here to enter the 2017 Colusa County Fair!

ONLINE entry deadlines

Container plants - May 12

Artistic design (arrangements and table settings) - May 12

Cut Flowers - June 5

Agriculture (herbs, veggies, fruit) - June 5


Disclaimer: the official rules and deadlines are in the 2017 fair book.


Make an Online Gift to UC Master Gardeners

May in the Garden

What to plant?

  • Direct seed in the garden cucumbers, melons, summer squash, beans, corn, and annual herbs.
  • Plant sunflowers, zinnias, cosmos, marigolds and aster in the flower garden.


  • Fertilize summer blooming flowers early in the month.
  • Apply (or re-apply as needed) organic mulch to all beds to keep the soil cool and enrich the soil. Be sure to leave space around the base of the plants.
  • Trim the dead flowers but not the leaves from spring bulbs. The leaves restore the bulb; so wait to remove them until they turn yellow. Fertilize the bulbs after the bloom is finished with bone meal.
  • Later in the month prune spring flowering shrubs to shape, removing old and dead wood. The plants flower on the growth that happens during the summer; do not prune in the fall or winter or you will have no flowers on the shrub.
  • Continue the battle against slugs and snails.
  • Deadhead (cut off spent flowers) to get continuing bloom on annuals and perennials.
  • Thin peaches, plums and nectarines so there is 6” between fruits.

Asian Citrus Psyllid

Asian Citrus Psyllid is an insect that carries a devastating disease in Citrus trees and there is no cure. The insect and disease is usually detected in home citrus first. Click here to read more about the Asian Citrus Psyllid and the Huanglongbing disease.

The Asian Citrus Psyllid has been found in San Joaquin County.

Click here to read about the Asian Citrus Psyllid from the UCCE Master Gardeners of San Joaquin County.

Click here for Spanish


UC Master Gardeners of Colusa County

100_2419 (2)


The University of California Master Gardener Program provides the public with UC research-based information about home horticulture, sustainable landscape and pest management practices. The program is administered by local University of California Cooperative Extension (UCCE) county offices that are the principal outreach and public service arms of the University’s division of Agriculture and Natural Resources.

The UC Master Gardener program supports sustainable gardening practices that protect the environment, conserve natural resources, and take into consideration each gardener's lifestyle and goals.


What do UC Master Gardeners do?

UC Master Gardeners are trained to help residents of California become better gardeners. Using a variety of activities such as workshops, lectures, and garden hotlines these volunteers answer questions about home horticulture, sustainable landscaping, and integrated pest management using University of California research-based information.

After their training UC Master Gardeners are qualified to help the public with problems in areas such as:

  • Weed Control
  • Plant Problem Diagnosis
  • Integrated Pest Management (insect and pest control)
  • Soils, fertilizers and irrigation
  • Selecting and caring for fruit and landscape trees
  • Growing annuals, perennials and food crops
  • Lawn care
  • Vegetable Gardening
  • Plant Pathology
  • Composting


Each county develops programs to address local needs. Some typical activities are:

  • Using mass media to disseminate gardening information
  • Teaching workshops, or lecturing on gardening practices
  • Participating in research activities with academics within UC
  • Answering gardeners’ questions via email or helplines
  • Speaking to the public on horticultural and gardening topics
  • Manning county fair information booths
  • Consulting with gardeners to improve their landscape practices


Find us on Facebook



Event Name

Garden Advice and Workshops

Native Bees and Bee Boxes workshop

Saturday, June 24

10am - noon

100 Sunrise Blvd., Conference room, Colusa

$10, prepayment is required

Garden Advice at the Colusa County Fair

Scavenger hunt

June 8-11

Etchepare Hall

Colusa County Fairgrounds


Featured Plant


California fescue


Medium size

California native




Master Gardener Blog

Monarch Sightings in the UC Davis Arboretum: Cause for Celebration

A monarch on milkweed in the UC Davis Arboretum. (Photo by Kathy Keatley Garvey)

What a delight to see. We strolled through milkweed patches in the UC Davis Arboretum Thursday noon and saw them. Monarchs! The monarch butterflies (Danaus plexippus) are returning from their coastal California overwintering sites. And we're getting...

Posted on Friday, May 26, 2017 at 6:28 PM

Christine Merlin and Monarchs: How They Use Their Circadian Clocks for Seasonal Migration

Christine Merlin, shown here examining a monarch butterfly, will speak on

Did you know that monarch butterflies use a circadian clock to navigate to their overwintering sites during their seasonal long-distance migration? Yes, they do, says a Texas A&M researcher. Christine Merlin, an assistant professor in Texas...

Posted on Thursday, May 25, 2017 at 4:59 PM

Bumble Bees: Pollen Power in the Phacelia

It's mine--move away! Two bumble bees, species Bombus vandykei, seek the same Phacelia blossom on the UC Davis central campus. (Photo by Kathy Keatley Garvey)

Talk about pollen! The bumble bees, Bombus vandykei (as identified by Robbin Thorp, distinguished emeritus professor of entomology at the University of California, Davis), were buzzing all over the Phacelia last week on the central campus. One bumble...

Posted on Wednesday, May 24, 2017 at 5:10 PM
Tags: Bombus vandykei (4), golden pollen (1), Phacelia (2), Robbin Thorp (197), UC Davis (114)
Webmaster Email: