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Healthy trees provide tremendous environmental and community benefits, and require a minimal investment in water to stay healthy. Photo: Valiphotos / Pexels tree care tips

Tree Care Tips Preserve Benefits During Drought  

Trees are among the most valuable investment in San Diego County’s landscape – including your own waterwise landscaping. Trees stand out as key performers in your landscape design for multiple reasons. No other landscape plant offers greater benefits to your landscape and the greater environment.

Investing in tree maintenance is vital to keep them healthy. As you reassess your landscaping’s irrigation needs during extended periods of drought, allocate sufficient water to your trees, which will in turn provide multiple benefits.

Trees need time to grow and reach maturity. Saving water in the short term during a drought could result in damaged or dead trees, which could take decades to restore. According to the San Diego Regional Urban Forest Council, the cost of watering a mature tree is less than $20 each year. It can cost $1,000 to remove a dead tree. Taking care of your trees during drought ensures a tremendous return on this investment.

Multiple long-term benefits from trees

Healthy trees fight climate change and cool our cities, provide habitat, and improve the health of our neighborhoods. Photo: Kampus Production / Pexels

In the region’s dry and increasingly warming Mediterranean climate, trees help fight climate change. Trees counteract the urban heat island effect, especially in areas dominated by hardscapes such as streets, sidewalks, and building roofs. The evapotranspiration from tree leaves cools the ambient temperature down, much as perspiration lowers a person’s body temperature. Watering your trees also reduces the water needs of plants growing in their shade.

Trees provide habitat for insects, pollinators, birds, and animals – and human beings with their welcoming shade and protection. Placed properly, shade trees can reduce the use of air conditioning from 20% to 50%. The evaporation from a single tree can produce the cooling effect of ten room-size residential air conditioners operating 20 hours a day. California street trees alone save the amount of electricity it would take to air condition 530,000 households every year.

Trees protect your property, and studies show the presence of trees improves property values. Neighborhoods with more trees have lower crime rates. In business districts, trees attract customers. People linger and shop longer when trees are present. Sales rise and benefit the entire economy.

Prevent wildfire risks with healthy trees

Even the strictest drought restrictions allow for watering trees on residential and commercial properties. Photo: Helix Water District tree care tips

Even the strictest drought restrictions allow for watering trees on residential and commercial properties. Photo: Helix Water District

When trees die off due to drought, they become wildfire safety risks in addition to losing their many environmental and economic benefits. While any plant might die off without sufficient water, it may grow back within weeks. Drought stress can make living trees more susceptible to diseases and pests.

Even the strictest drought restrictions allow for watering trees on residential and commercial properties. The preferred method is to use a slow-release method such as a perforated bucket or low-volume non-spray irrigation.

Effective ways to water trees

When watering your trees, water along the dripline below the canopy edge, not at the trunk. Diagram: San Diego Regional Urban Forestry Council tree care tips

When watering your trees, water along the dripline below the canopy edge, not at the trunk. Graphic: San Diego Regional Urban Forestry Council

Trees need deep infrequent watering. Once established, once a month in the summer and during months without measurable rainfall is sufficient.

  • Newly planted trees: For the first three years, water once weekly with up to five gallons of water.
  • Small, established low water trees need only about 20 gallons a month. This is the same amount of water in a single average shower.
  • Larger, mature low water trees need up to 200 gallons per month.
  • Monitor the soil moisture under your tree and adjust amounts accordingly. You may want to use a soil probe to check at the roots.
  • Apply water at the edge of the tree’s canopy, not at the trunk. This is where the roots absorb and bring water into the tree.

Trees create community. They provide inviting and cool areas for recreation and relaxation in our neighborhoods and contribute to playgrounds and parks. San Diego enjoys a perfect example right in the heart of the city. One of our greatest civic attractions is Balboa Park, full of beautiful trees planted by visionaries like Kate Sessions a century ago.

Find additional advice from the San Diego Regional Urban Forests Council on tree care and drought.

Padre Dam Municipal Water District-Landscape Makeover Winner-WaterSmartSD-drought

Hard Work Pays Off for Padre Dam Landscape Makeover Winner

Frank Edward’s Santee home is bursting with bright colors and textures. Vibrant yellow, orange, red, green, and purple flowers, and drought-tolerant, native plants spring to life where there was once just dry and patchy grass.

“It was a lot of hard work but it was also a lot of fun,” said Edward. “It was great to see all of my labor come to fruition.”

The transformation from high maintenance lawn to vibrant design is the winner of the 2021 Padre Dam Municipal Water District Landscape Makeover Contest.

Before transformation

Frank Edward'a home before his award-winning landscape. Photo: Padre Dam Landscape Makeover

Frank Edward’s home before his award-winning landscape redesign. Photo: Padre Dam Municipal Water District

After transformation

The results of Frank Edward's hard work. Photo: Padre Dam MWD

The results of Frank Edward’s hard work. Photo: Padre Dam Municipal Water District

Edward began his water-efficient landscape journey in 2018 when he attended a three-hour WaterSmart Landscape Workshop at Padre Dam’s customer service Center. He was tired of his high maintenance, drought-bleached lawn and wanted his landscape to add to the overall attractiveness of his home.

During the workshop, he learned about the WaterSmart Landscape Makeover Series, a four-class series that helped him through the process of preparing his space, designing his landscape, selecting plants, and irrigation planning. Edward used a kidney bean shaped planter as a starting point and designed his landscape around this feature.

“Hard work but a lot of fun” to complete landscape makeover

Frank Edwards had a complete plan after attending the Water Authority's WaterSmart Landscape Makeover Series. Photo: Frank Edwards Padre Dam Landscape Makeover

Frank Edwards had a complete plan after attending the San Diego County Water Authority’s WaterSmart Landscape Makeover Series. Photo: Frank Edwards

Edward had a fully designed layout ready to be implemented by the end of the class series. He set to work removing his old turf and installing his new landscape in the spring of 2019 and did all of the removal, designing, and planting himself. He even constructed a small barn that acts as a shed and a footbridge over his riverbed to add unique and functional design elements. The work took about a year to complete. Water storage features including a small pond and rock river bed, which add depth and shape to the contoured yard.

The new yard has places to sit and enjoy the flowers, pollinators, and bird. Photo: Padre Dam MWD

The new yard has places to sit and enjoy the flowers, pollinators, and birds. Photo: Padre Dam Municipal Water District

Edward installed piping to collect water off his roof, collected in a rain barrel, and diverts it to the landscape’s rock river bed. Additionally, he created a pond that can hold several hundred gallons of water. This collected rainwater helps to irrigate the plants by replenishing the soil’s moisture for a period after it rains. Edward also installed a smart controller that waters the plants based on hydrozones and local weather through a drip irrigation system.

Neighbors compliment Frank Edward on his efforts. Photo: Padre Dam Municipal Water District

Edward now spends time relaxing and listening to birds in his front yard. He enjoys the peaceful atmosphere and the satisfaction he gets when neighbors and passersby compliment his landscape. He recommends that others looking to plant a water-smart landscape put in the time to research and plan in order to create an environment and design that will work for their lifestyle.

“Hard work and a well-thought-out plan certainly paid positive results,” said Edward. “It was a great success.”

(Editor’s note: The Padre Dam Municipal Water District is one of the San Diego County Water Authority’s 24 member agencies that deliver water across the metropolitan San Diego region.)

Hydrozones-Conservation Corner-landscaping

Know the Hydrozone Game Rules

Hydrozones are the different areas of your landscaping where plants with similar irrigation needs are grouped together.  This allows you to apply water as efficiently as possible through rainwater catchment, supplemented by irrigation, while avoiding unnecessary and wasteful overwatering.

Sun exposure, slopes, and plant root depths need to be taken into consideration along with plant water needs. All these characteristics create specific hydrozones. Even when the soil is the same, a full sun area is one hydrozone, full shade areas are another, and mixed exposure areas create yet a third. Shade from buildings or trees can also raise or lower temperatures.

Each irrigation valve should water its own separate hydrozone populated by plants with similar water needs, living conditions, and root depths. Plants with high water needs such as vegetables or lawns need to be grouped into their own hydrozone. Sprinklers or emitters on this zone shouldn’t overwater anything else.

Don’t overdo it with your irrigation

Inspect your sprinkler heads regularly to make sure they are not obstructed or watering onto pavement or other hardscapes. Photo: Irrigation Association

Inspect your sprinkler heads regularly to make sure they are not obstructed or watering onto the pavement or other hardscapes. Photo: Irrigation Association

Each hydrozone must be able to handle enough water volume for every emitter to work properly. Hydrozones should have individual sprinklers or emitters delivering only the required amount of water, spaced out so every plant in the hydrozone receives an equal and accurate amount. If two sprinklers cross over one another, plants receiving water from both will receive more water than needed. In this example, sprinklers should be turned away from each other, or be reset farther apart. Professional landscapers call this “matched precipitation.” 

This article is part of a year-long series inspired by the 71-page Sustainable Landscapes Program guidebook available at SustainableLandscapesSD.org. The Water Authority and its partners also offer other great resources for landscaping upgrades, including free WaterSmart classes at WaterSmartSD.org.