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 834 hours and made 1191 face to face contacts in 2017/18.

Since 2009, we have volunteered 5,798 hours and made 11,447 face to face contacts in Colusa County.


This is what we do!

Click here for a short video!



Need help identifying insects and how to get rid of them? The UC IPM (Integrated Pest Management) has answers!

UC IPM website


Do you want to become a Master Gardener?

The UC Master Gardener Program of Colusa County is now accepting applications for our 2019 training.

Training will start February 6 and end May 22. The training will occur in Yuba City but you will volunteer in Colusa County.

The Meet the Master Gardeners informational meeting is January 3 at noon. Applications are due at this time.

Download an application here.

Complete application, 2019

Preparing for a Frost




Before a frost

  • Identify cold spots in the landscape by monitoring with thermometers
  • Identify plants at risk: citrus, succulents, tender perennials, tropical and subtropical plants.
  • Have supplies ready: sheets, blankets or frost cloths, lights, wraps for trunks, thermometers, stakes or framework to hold covers off foliage. Frost cloths come in different weights that can provide 4 to 8 degrees of protection. Because the frost cloth allows some light and air to penetrate, it can stay on plants for a few days at a time. Frost cloth can lie directly on plant foliage.
  • Prepare tender plants: avoid fertilizing and pruning after August to minimize tender new growth.
  • Rake away mulch to allow soil to warm up during the day and radiate heat into the plant at night.
  • MONITOR weather forecasts and note how low temperatures will be and for how long.

o   Local frost: clear, dry nights, usually warms during the day.

o   Hard freeze: temperature inversion or Arctic front, can last for days or weeks, are very damaging.

When a frost is forecast

  • Move plants to a warmer spot next to the house or under a patio cover, especially on the south side.
  • Check that plants are well watered because dry plants are more susceptible to damage, and moist soil retains heat better than dry soil.
  • Cover plants before sunset to capture ground heat radiating upward at night. Remove sheets, blankets and other covers daily if it is sunny and above freezing to allow soil to absorb heat.
  • Add heat by using outdoor lights: hand 100 watt drop lights or holiday string lights to interior of plant. Use the old C7 or C9 large bulbs, not new LED lights which do not give off heat. Old style holiday lights that give off heat can provide up to 3 degrees of protection. Use lights, extension cords, and multi-outlets or power strips that are rated for outdoor use and grounded (3-prong). Avoid connecting together more than three light springs in a line.
  • Wrap trunks of tender trees if a hard freeze is expected, using towels, blankets, rags, or pipe insulation. Also wrap exposed pipes the same way.
  • Harvest ripe citrus fruit. Generally both green and ripe fruit are damaged below 30 degrees, but there is some variation by species.


For more information, click here to visit the UC Master Gardeners of Sacramento County page on frost protection.

Thank you, UC Master Gardeners of Sacramento and San Joaquin Counties for the information.


November in the Garden

November garden tasks: 

  • You can still sow seeds of wildflowers this month. Plant California poppy, calendula, clarkia, and sweet peas.
  • In the veggie garden plant seeds for lettuce, mustard, spinach, radishes and peas.
  • If you didn’t get your new tree planted last month, it is not too late to take advantage of the fall root growth that will give your new tree a strong start in the spring.
  • Look at your camellias and remove excess buds to get larger flowers.
  • In the middle of the month fertilize the veggies and flowers that were planted in October.


Also, this is the time to plant the chilled bulbs, and the spring flowering tubers and corms. Clean up all the fallen/falling leaves and other plant debris and dispose of diseased materials.

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


Make an Online Gift to UC Master Gardeners

Find us on Facebook



Garden Advice and Workshops

 Make & Take Craft Expo

November 3

9am to 3pm

Colusa County Fairgrounds

Open to the public


Wreath Workshop

December 1

10 am to noon

Colusa County Fairgrounds, Community Center




Master Gardener Blog

UC Davis Researcher Targeting Zebra Chip: It's Not a Chip You Want

The potato psyllid, a pest of potatoes, transmits a bacteria that causes zebra chip disease. (Photo by Don Henne)

When you're munching on French fries or potato chips, you're probably not thinking about the potato psyllid. But you should be. You should especially be thinking about the zebra chip. No, it's not a newly marketed potato chip or computer...

Plant Communication Research: 'Taking Root'

UC Davis ecologist Rick Karban has researched plant communication in sagebrush (Artemisia tridentata) on the east side of the Sierra since 1995.

It's not outlandish now, if it ever were. A recent article in Science headlined "Once Considered Outlandish, the Idea that Plants Help their Relatives Is Taking Root," and dealing with how plants communicate, is drawing widespread...

Drum Roll...First Bumble Bee of the Year!

Check out the pollen on this black-tailed bumble bee, Bombus melanopygus, nectaring on manzanita, as photographed by Kim Chacon, UC Davis doctoral candidate on Jan. 10.

We have a winner! Several UC Davis bumble bee enthusiasts--encouraged by native pollinator specialist Robbin Thorp, UC Davis distinguished emeritus professor of entomology--compete every January to find the first bumble bee of the year in Yolo and...

Webmaster Email: