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 802 hours and made 1458 face to face contacts in 2014/15.



This is what we do!

Click here for a short video!



2016 UC Master Gardener of Colusa County calendar


Order your 2016 calendar on-line and we will mail it to you! Calendars are $13.00 when ordered on-line. The price includes tax and shipping.

Click here.


Inspect Your Landscape Trees For Hazards

The drought has been hard on our trees. Even if you watered your trees throughout the summer, our trees have suffered. As we have heard, it should be a wet year. This can cause our trees some problems.

November is a great time of the year to inspect our landscape trees for hazards. Most of the leaves have fallen, leaving a clear view of the tree structure. Although some tree failures are not predictable and cannot be prevented, many failures can be prevented. By inspecting trees for common structural defects, many potential failures can be corrected before they cause damage or injury.

Stand back and look at the whole tree. Thoroughly inspect the tree for defects in the following order.



Multiple trunks         

Weakly attached branches

Cavities and decay

Cracks in the trunk and branches

Hanging or broken branches

Dead branches

For details and pictures, click here. Pages 6 and 7 have detailed pictures.


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. 

City of Colusa, Williams and Arbuckle water restrictions

Click on the file to read about your city restrictions.

City of Colusa

City of Williams

Arbuckle Public Utilities District

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

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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


Garden Advice and Workshops

2016 Events

Watch for details in our newsletter!


Rose Pruning workshop, Saturday January 30

Fairy Garden workshop

Plant Clinic, Friday March 25, Griff's Feed and Seed, Colusa

Succulent workshop, Thursday March 31

Gourd workshop



Featured Plant


California fescue


Medium size

California native




Master Gardener Blog

'Fourteen' Is a Lucky Number: That's Where the Monarchs Are

Roosting monarchs at the Berkeley Aquatic Park look like dried leaves, as one observer said. (Photo by Kathy Keatley Garvey)

"Fourteen" is a lucky number at the Berkeley Aquatic Park, 80 Bolivar Drive, Berkeley. Fourteen is considered a day of love and romance, as in the 14th of February, Valentine's Day. But at the Berkeley Aquatic Park, it's also love. Love at first...

Posted on Friday, November 27, 2015 at 4:35 PM

When Material Possessions Tear at the Very Fabric of Our Lives

Monarch butterfly spreading its wings. (Photo by Kathy Keatley Garvey)

When material possessions tear at the very fabric of our lives, it's time to re-weave and re-think. “Gimme more, gimme more, gimme more!” seems to be the mantra of the rich and famous and the faux rich and famous. From my perspective: It's...

Posted on Thursday, November 26, 2015 at 1:00 AM

Thankful for Beneficials

Jumping spider

Thanksgiving is a time to gather together with family and friends. The occasion is usually centered around a big meal followed by pumpkin pie, and hopefully some time to let each person share a list of what they are most grateful for that year. Here at...

Posted on Wednesday, November 25, 2015 at 2:03 PM
Tags: beneficial (2), insects (26), lady beetle (13), mites (2), natural enemies (2), predator (7), spiders (9), thankful (1), UC IPM (28)
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