Standing in the usually snow-packed Sierra Nevada Mountains, Gov. Jerry Brown called for a mandatory reduction of water use across California the beginning of this month. For the first time in the state a required water conservation action has been called, shedding light on the severity of California's drought conditions.

At the direction of Gov. Brown the State Water Resources Control Board will require local water districts to impose a 25 percent water restrictions on all resident's water use.

“People should realize we are in a new era,” Brown said. “The idea of your nice little green grass that gets water every day, that's going to be a thing of the past.”

These new mandatory restrictions have left many home gardeners to wonder what this means for their home landscape.

Reducing Water Use in the Garden

According to The California Garden Web, an informational website about gardening hosted by the UC Master Gardener Program, water use in the home landscape can often be easily reduced by 20 to 40 percent because overwatering is a common mistake by homeowners. Slowly start to reduce water supplied to plants over the course of a few weeks, giving the plants time to adapt to the change.

It is important for residents to remember to not introduce new plants to your landscape during a severe drought. Even California native plants aren't drought-tolerant until they become well established. When water restrictions are lifted and new plants can be introduced, select drought-tolerant varieties appropriate for your climate zone. 

Planting in the fall as opposed to the spring allows plants to become established by winter rains. Residents should prioritize water use in their landscape, saving established trees and large shrubs first because they are typically more expensive to replace and require years to mature.

The lawn should be given a low water priority. As Brown stated during his address, “nice little green grass that gets water every day, that's going to be a thing of the past.” The lawn is often underused and typically mismanaged with overwatering in the home landscape. Lawn can easily be reestablished over a short period of time, or replaced with ground covers, mulches or hardscapes. If saving a lawn is a must, remember to mow your lawn higher during very warm weather and only water at night between 9 pm and 6 am.

UC Master Gardener Program Offers Help

The UC Master Gardener Program has volunteers across the state, trained by University of California Cooperative Extension (UCCE), available to answer the public's questions about how to save established trees, plants and reduce water use in their yards.

Many of the program's 50 county-based locations offer free to the public hotline services, home irrigation analysis and workshops for the public that are aimed at helping California's residents reduce their water use. Contact a local UC Master Gardener Program for more water saving information and resources.

Trusted Resources

The new second edition of the California Master Gardener Handbook from the UC Division of Agriculture and Natural Resources (UC ANR) is a great resource for drought tips and home landscape water conservation methods. With an extensive chapter dedicated to water conservation methods, best practices for irrigation, plant selection, and tips for protecting water quality in urban landscapes.

Another great option is to use the irrigation worksheet for homeowners that was recently developed by Dr. Loren Oki, CE Specialist, Landscape Horticulture with UC ANR and UC Davis. The worksheet is designed to calculate an irrigation schedule for a landscape zone for one calendar year.

 

From a majestic oak, giant sequoias or a swaying palm there is nothing quite as beautiful in this world than a tree. They can provide us with shade, fruit, flowers and most importantly are the “lungs of planet”.  While we have enjoyed some wet weather over the last week, California is still suffering from extreme drought conditions.

Prioritizing Trees for Landscape Water Use

Many residents have been encouraged to reduce water use by turning off their outdoor watering systems, but this may be causing stress to established trees that are becoming increasingly thirsty for water.

In most traditional residential landscapes trees are surrounded by turfgrass. Turfgrass surrounded trees take advantage of the frequent and shallow watering schedule, typically set to help the lawn flourish. When residents eliminate or reduce water for lawns, trees cannot easily adapt to the new water shortage.

“Mature fruit trees and landscape trees are worth saving! Recognizing early signs of drought stress is important because irreversible damage can occur that no amount of watering will correct.” said Janet Hartin, UC Cooperative Extension advisor in a recent article, Save Water, But Also Save Trees During a Drought.

Replacing small plants, lawns and shrubs is easy compared to a large tree which takes years to become established. Saving mature trees during a drought should be a top priority in your landscape water use allocation.

“Two seasons without enough water can result in severe drought stress and even kill a tree,” warned Hartin. “Also, drought-stressed trees are more prone to damage from diseases and insects than non-stressed trees.”

Understanding how to water a tree effectively is important to avoid water waste and to ensure that the tree is receiving the correct amount of water for its survival.

One key factor to successfully watering a tree is understanding what soil type is present. Understanding soil types is an important factor in determining how much water is stored in the ground. For example, sandy soils dry out quickly while clay soils retain more water. Contact your local UC Master Gardener Program to learn how to determine your soil type.   

Another important factor is understanding tree anatomy for watering (see Figure 1). The tree roots of a mature tree are found in the top three feet of soil and extend outside of the tree's canopy. This outside area of the tree roots is the most active absorption area.

Tree Ring Irrigation Contraption (TRIC)

Recently the Calif. Center for Urban Horticulture (CCUH) at UC Davis, UC Division of Agriculture and Natural Resources (ANR) and Ewing Irrigation devised a unique watering system called the Tree Ring Irrigation Contraption (TRIC).   Using previous data from Netafim drip tube tables and from the Irrigation Association Landscape Irrigation Auditor manual, the partners envisioned a possible solution to mitigating drought conditions and the effect on landscape trees.  The TRIC is an inexpensive kit that homeowners can put together for around $100 for one large tree.  

The TRIC could enable homeowners to adequately water trees to a depth of three feet with confidence, by using the recommended parts and using the TRIC calculator with accurate information. Aside from a recommended parts list, there is a “plug-in” calculator created by Dr. Loren Oki, UC ANR Associate Specialist in Cooperative Extension Landscape Horticulture for UC Davis & UC ANR. The TRIC calculator helps determine the run-time needed for the device.

Learn more by visiting:

• CCUH – Tree Ring Irrigation Contraption website
• TRIC Parts List
• TRIC Calculator
• TRIC PowerPoint Presentation