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Master Gardeners


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UC Master Gardener’s UC ANR #Giving Day is today! May 16 & 17, noon to noon. Join us at noon and be the first to give—or visit our Facebook page anytime as we highlight the impact of our program across the Colusa County.

Donations fund the Donna Critchfield demonstration garden at the Education Village in Williams. Vegetables from the garden go to local food banks.

Thank you to our sponsors Alsco-Geyer Irrigation in Arbuckle and Messick’s Ace Hardware in Colusa. Stop in and thank them for their support.

Make your gift then share your support on social media using #Giving Day or call a friend to let them know what’s happening.

It’s the generosity of individuals and volunteers like you that support our efforts to bring practical, trusted answers to residents across our county. An investment in the UC Master Gardener Program of Colusa County represents an investment in Colusa County’s present and future.

Click on the "Make a Gift" button to donate.


Our Digital Footprint

How a program of 18 volunteers became Internet Influencers and made 320,000 impressions in 3 years!

Colusa County SFE poster


 Science based solutions for Colusa County's gardening communities.

The UCCE Master Gardeners of Colusa County volunteer's donated 705 hours and made 736 face to face contacts in 2018/19.

Since 2009, we have volunteered 6,475 hours and made 12,154 face to face contacts in Colusa County.


This is what we do!



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.
Water Trees First

TRIC lawn

Our trees are the most important garden asset. They provide shade, clean the air, provide habitat for wildlife, they are beautiful and increase your property value.

A new way of irrigating trees have been developed by the University of California. As you see in the picture you will circle the tree with a drip line or soaker hose to the edge of the canopy. You can purchase supplies at your local garden center or hardware store.

To get the deep watering need for trees, you will need to run the drip line for several hours but only irrigate every 2-4 weeks. The water needs to penetrate the soil about 2-3 feed deep.

For more information from the California Center for Urban Horticulture, click here.


Water-wise tips



Create drought resistant soil

  1. By incorporating 2-4 inches of compost into the soil you will increase the water holding capacity of the soil.
  2. Topdressing compost around plants will reduce water needs but not up to the plant base.       Space @ the base.
  3. Mulch all exposed soil to reduce evaporation with bark, leaf litter or rocks


  • Reduced water usage


Grow California or Mediterranean natives

Check out the UC Arboretum All-Stars

  1. Plants thrive with little irrigation
  2. Planting in the fall allows the roots to grow without competition
  3. Irrigate until established
  4. Minimize high water use ornamentals


  • Reduce watering
  • Reduce trimming
  • Reduce fertilizing
  • Reduce spraying


Minimize the Lawn

  1. The use of native groundcovers, grasses, shrubs and trees make an eye catching garden
  2. Reduce the size of the lawn and plant Tall fescue. It is a cool season grass that does well in summer. Most cool season grasses need a lot of water to look good
  3. Avoid slopes, plant a ground cover instead of lawn


  • Conserve water
  • Conserve energy
  • Conserve labor        



  1. By grouping plants together by water and light needs plants tend to be healthy
  2. When you group your plants together by water and light needs then you can properly water each micro-climate
  3. Use California natives


  • Healthy plants
  • Conserve water
  • Less pruning


Irrigation System

  1. Remember to change your irrigation timer seasonally. Monthly adjustments are encouraged
  2. Use an automatic controller on your irrigation system
  3. Use drip for your flower and shrub beds
  4. Replace old sprinkler heads with high efficient ones. If your system is over 10 years old check out the new sprinkler heads at your local garden center
  5. Use multiple run times if you have a lot of run-off before the timer shuts off.  For example; you should irrigate every other day for 20 minutes but after 15 minutes the water is running off the lawn. Instead run the system for 10 minutes, wait 1 hour and run for another 10 minutes. This works especially well on slopes.


  • Limit evaporation and run-off
  • Limit disease
  • Limit weeds


Irrigate according to the season

  1. Know your watering needs
  2. Adjust watering to the season, use chart in Lawn Watering brochure
  3. Water early
  4. Water slowly
  5. Water deeply


  • Appropriate watering slows plant growth
  • Promotes plant health
  • Reduces pruning and mowing
  • It is estimated that overwatering causes 85% of all landscape problems


Make every Drop Count                 

  1. Water wisely and slowly.
  2. Mulch is one of the quickest, easiest and most cost-effective ways to save water
  3. Repair leaks and broken sprinklers
  4. Reduce overspray areas
  5. Adjust the system frequently to the season
  6. Mulching exposed soil reduces evaporation.
  7. Prevent urban drool


  • Conserve water
  • Save money
  • Urban landscape water use can be reduced by 50%


More information:

8 Smart Gardening Practices

How to save water in your garden

Keep Plantings Alive under Drought Conditions

Lawn Watering Guide for California

Lawn Watering

Rules of Thumb for Water Wise Landscape

Water Conservation checklist

Water Conservation Tips



California Garden Web

UC Guide to Healthy Lawns

River Friendly Landscaping

UC Davis Arboretum

UC Master Gardeners of Sacramento County

UC Master Gardeners of San Joaquin County




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

UC IPM website


UC Master Gardeners of Colusa County



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


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Event Name Date
Master Gardener Blog
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    By Kathy Keatley Garvey
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