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Irrigation-Conservation Corner-drought-Water Conservation

Choosing Your Best Irrigation Method: Spray or Drip

Your choices in irrigation methods come down to spray or drip systems. Spray irrigation emits water in an overlapping pattern. Drip irrigation delivers water directly to the roots of plants. This question is more important than ever during a drought cycle. How do you decide which meets the needs of your landscaping?

The case for spray irrigation

Ensuring that spray heads are properly tuned and far enough away from buildings or impermeable surfaces helps maximize your water efficiency. Photo: California Department of Water Resources

Ensuring that spray heads are properly tuned and far enough away from buildings or impermeable surfaces helps maximize your water efficiency. Photo: California Department of Water Resources

Spray irrigation can be an efficient way to irrigate large landscapes with groundcover or uniform plant materials like lawns or meadows.

Spray systems apply water in gallons per minute, so if you know the application rate of each spray head, the distance between the heads, and the pressure of your system, it is relatively easy to figure out how much water is applied every time you run your irrigation.

Low volume spray heads apply water at about one-third the rate of conventional spray heads. Newer spray irrigation heads have improved spray with heavier droplets more resistant to wind. Landscaping with grade changes using spray heads should have check valves installed to prevent water flowing out of the lower point heads.

Challenges of spray irrigation include narrow areas surrounded by hardscape or irregular patterns. Irregular patterns are particularly challenging because spray irrigation requires head-to-head coverage to be efficient. Odd-shaped areas may be under or overwatered. High-volume spray heads that emit water at a much higher rate than the soil can absorb should be replaced.

The case for drip irrigation

Drip systems apply water in gallons per hour, so they often need to run for longer periods of time than spray systems. But the actual run time must always account for precipitation rate and runoff.

Installation of subsurface systems (under at least two inches of mulch) is the most efficient way to irrigate nearly every type of garden area. Since the tubing is flexible, it can accommodate a variety of irregularly shaped areas or rectangular areas when laid in a grid pattern, and in rings you can easily expand as trees or shrubs grow.

Challenges of drip irrigation include the application of water too quickly for your soil to absorb. This needs to be considered when dripline grids are installed. Drip irrigation operates the most efficiently at low pressure (between 15 and 30 PSI). To achieve optimal performance, pressure regulation either at the valve or at the point of connection of the dripline to the buried lateral lines must be used. It is also essential to install some type of filtering system to keep the emitters from getting clogged.

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

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

Give Your Irrigation System a Fall Checkup

Staying on top of your irrigation system – especially in the midst of a drought – can mean the difference between maximizing your water efficiency and unknowingly wasting water running down sidewalks unused into the storm drain. Follow these tips for a thorough checkup.

Turn on each valve of your irrigation system and observe how quickly water begins to run off your landscaping. Note the time when each runoff occurs. For some systems, this could be immediate. For others, it may take as long as five minutes.

Make sure spray irrigation is never running for longer than eight minutes at any one time.

Take notes on your irrigation plan, and turn off your irrigation until you can fix the following issues:

  • Do you have broken sprinkler heads?
  • Are there heads that are blocked by plants or objects such as planters or lights?
  • When the system turns off, does water come out of the lowest heads in the landscape?
  • Are any heads in need of adjustment, so they don’t directly spay onto the hardscape, such as sidewalks or patios?

Adjust your sprinklers to eliminate runoff

Don't allow your spriinklers to overspray your landscaping and waste water. Photo: Wikimedia irrigation tips

Don’t allow your sprinklers to overspray your landscaping and waste water. Photo: Wikimedia

Several things can be done to minimize runoff due to irrigation. This is among the most important factors in using irrigation efficiently.

  • Tune up spray irrigation systems, so there is no overspray on hard surfaces
  • Do not install spray irrigation in areas that are too narrow (generally eight feet wide or narrower)
  • Move spray heads 24 inches away from buildings or impermeable surfaces
  • Convent spray systems to micro or drip irrigation with pressure regulation and a filter
  • In lawn areas, be sure to follow the organic maintenance practices to keep your soil ‘spongy’ (link to soil post)
  • Replace standard overhead sprayers with high-efficiency rotator nozzles, or other types of low precipitation rate nozzles

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

A large tree's roots are concentrated at the dripline, not at the trunk. This is where you should irrigate the tree through a slow release technique. Photo: Hans Braxmeier, Pixabay tree watering tips

Borrow Tree Watering Tips from Mother Nature

As drought continues to affect California, homeowners must balance two needs: preserving landscaping with irrigation while doing so as efficiently as possible to conserve water.

Even when not in a drought, trees planted in a Mediterranean climate often need additional water. For the most effective irrigation, mimic the way Mother Nature provides water.

Nature designed trees so rain would fall on the leaves and run off to the sides of the tree – much like rain hits an umbrella and rolls down off the side. It falls in a circle around the perimeter.

When irrigating trees, this same approach provides the most moisture to roots and maximizes water use. This outer edge around a tree where rain falls is called the drop line. This is where the tree sends out its most vigorous feeder roots to soak up available moisture. Using a hose to water at the trunk of trees doesn’t reach many of the roots.

Focus on slower, infrequent tree watering

Focus on longer, slower delivery of water than mimics a long, light rainfall. Photo: Ulrike Leone

When it does rain, Mother Nature’s rainfall is primarily steady, slow, and spread out. Borrow this method to deliver a long, slow soaking. Trees prefer infrequent deep watering. Once a week or less for more established trees is sufficient.

Water in a slow drip away from the trunk, long enough to soak the top 12 inches of soil in the drip line. Use a hose on a very slow trickle, a soaker hose, drip irrigation in the proper areas, or this clever method.

Use a five-gallon bucket with small holes to slowly release water to a tree’s deepest roots. Photo: Sacramento Tree Foundation

Use a five-gallon bucket and poke several holes in the bottom. Put the bucket on top of the soil along the drip line. Fill the bucket with water. The water will seep out slowly and deeply into the soil. When it’s empty, move the bucket about three feet away, and repeat the process. Do this until you have made a circle in the drip line around the tree.

You can fill the bucket with water gathered in your daily shower. In a household with several people, you may be able to fill a five-gallon bucket daily. Water early in the morning or after sunset, so you lose less water to evaporation. This is when trees gather moisture naturally.

If you have hard, rocky ground, drill holes one foot deep every three feet around the tree along the drip line. Fill the holes with compost, and then pour water into them. This vertical mulch will encourage the roots to grow.

Finally, bear in mind turf competes with your trees for water. Even if you want to retain some lawn, it’s smart to remove the lawn immediately around your trees and replace it with WaterSmart landscaping.

Following a few smart irrigation tips will make the most of the water applied to your landscaping. Photo: Vallecitos Water District

Smart Landscape Irrigation Tips Save Water

During drought, it’s more important than ever to conserve water used for irrigation. When you follow just a few smart landscaping irrigation tips, you can get the most from every drop of water applied to your landscaping.

Don’t overspray your landscaping

Don't allow your spriinklers to overspray your landscaping and waste water. Photo: Wikimedia irrigation tips

Don’t allow your sprinklers to overspray your landscaping and waste water. Photo: Wikimedia

Watch your irrigation while the system is running. Check to make sure sprinkler heads aren’t spraying water onto sidewalks, patios, or structures.

If water is being applied too fast for your soil to absorb, runoff will occur. This needs to be prevented.

Puddling and pooling water may be an indication your water is being applied too fast or too often. Adjust your system until this isn’t happening anymore.

Repairs to broken pipes and sprinkler heads should be made immediately, or your system should be turned off until those repairs can be made.

Eliminate runoff with cycle and soak programming

Watch how quickly runoff happens when running irrigation. This is the maximum run time for your irrigation controller in a particular hydrozone.

Divide the total irrigation minutes recommended for the specific hydrozone condition into shorter blocks of time before runoff starts. For example, if you should irrigate for 15  minutes but runoff starts within five minutes, irrigate in three five-minute cycles. Allow a 30-minute rest period in between irrigation cycles.

Hand watering that works

Hand watering can be an effective method to water your landscaping. Photo: Ryan McGuire / Pixabay irrigation tips

Hand watering can be an effective method to water your landscaping. Photo: Ryan McGuire / Pixabay

Hand watering is especially good when your garden is getting established. You can spend more time watching your plants to be sure they are flourishing in the early stages.

When your landscape plants are new, you may need to water more frequently because roots are shallower. Roots on a newly planted one-gallon plant are only four to ten inches deep. This is why it’s a smart idea to plant during the rainy season.

Before hand watering, look at your plants. Do they appear droopy? Is the soil very dry? If so, give the plants a good drink. Don’t water more than two days in a row. Let the soil dry out completely before watering again. Overwatering and underwater symptoms can be similar.

Once your plants are established after the first year, your sustainable garden will  not need watering more than once or twice a month – if at all. Stop watering after the first seasonal rains begin and let nature take over.

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

Efficient irrigation-landscaping-Conservation Corner aspects of sustainable landscaping can help you ensure the success of your project. Photo: Water Authority landscape professional

Efficient Irrigation Delivers Water While Protecting Plants

Due to the lack of rainfall in the San Diego region, even sustainable landscaping sometimes relies on artificial irrigation. Irrigation systems must be thoughtfully designed, installed, and programmed. Once in place, the many interconnected mechanical elements must be maintained properly for optimal performance.

“Irrigation efficiency” is a way of describing how well your irrigation system is doing its job delivering water for the beneficial use of the plants in your landscaping.

When irrigation system efficiency isn’t maximized, it can cause you to use more water than needed. Possible problems fall in three major categories: site conditions in your landscaping, irrigation control, and the uniform distribution of water by your irrigation system.

How to maximize irrigation impact

You may want to get help planning your irrigation system from a qualified professional. Photo: San Diego County Water Authority

There are three ways to improve your irrigation system efficiency:

  • Smart Irrigation Management
  • State of the Art System Upgrades
  • Matching Irrigation to Your Hydrozones

Setting and forgetting your irrigation controller is a thing of the past. Even if you don’t have a “smart” irrigation controller to adjust your program for weather conditions, be more proactive in managing your watering, and more closely try to match your watering schedule with the actual water needs of your landscaping.

Upgrading your system with state-of-the-art components is a good investment and the single most significant thing you can do to save water.

Tips on professional help

You may decide to get professional help with your irrigation system. Look for designers or contractors qualified to provide these services. Credentials such as the Irrigation Association’s Certified Irrigation Designer designation can help assure your project will be successful. You can also ask if your contractor is a Qualified Water Efficient Landscaper (QWEL).

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

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.

Saving water-water bank-Conservation Cornerrainy day can be used later. Photo": Werner Jukel / Pixabay Bank your water savings

Bank Your Water Savings for the Future

Using landscape irrigation efficiently can significantly reduce overall household water consumption while leaving adequate water in the ground to cover your plants’ needs. One tool that can help is to build up your water savings when rainfall is available.

Approximately half of the water spent by average California homes is used outdoors, mostly for irrigation. Unfortunately, up to half of commercial and residential irrigation water is squandered by evaporation, wind, improper system design, or overwatering, according to the U.S. Environmental Protection Agency.

During the winter in metropolitan San Diego County, healthy soil can absorb water in surprisingly large quantities to be released slowly to plants as they use it during drier months – like using a savings account to pay for expenses over time.

There haven’t been many opportunities in recent years to do so. However, whenever it is possible, there is no need to use the residential water supply on your landscaping when Mother Nature can bank water savings deposits for you.

Balance your water bank account 

Maximize your landscaping soil's ability to retain and save rainfall and irrigation for drier days. Photo: D. Douk/Creative Commons

Maximize your landscaping soil’s ability to retain and save rainfall and irrigation for drier days by creating a water savings account. Photo: D. Douk/Creative Commons

Water entering the soil – whether as rain or as irrigation – is like a deposit into a soil checking account.

By keeping track of those transactions of water in and water out, it is possible to know how much water in the soil “reservoir” is available in the landscape at any given time for the plants to access.

The initial soil bank balance is determined by direct observation or is assessed after a thorough wetting of the soil by irrigation or winter rains. Every day, plants take small amounts of water from the soil. Rain and irrigation fill up the water bank again. The trick is to make sure this “account” does not get overdrawn.

How can you tell when the account is depleted? Smart irrigation controllers and landscape professionals can calculate this for you. You can also rely on a soil probe, or even testing the landscape by feeling the soil surface with your fingers.

When oxygen and water are balanced in the soil, the amount of water lost through evapotranspiration is similar to paying fees on your savings account. Shading the soil surface with plant materials and mulch protects water in the soil by slowing evapotranspiration and leaving more water in your soil’s account.

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

Compost-Conservation Corner-sustainability-WaterSmart-sustainable landscaping

Become a Compost Champion

Once your sustainable landscape makeover is in place, commit to best practices in maintenance. This includes regular composting.

Compost can also be used as mulch, applied directly to the soil surface. It can prevent erosion and help plants, and soil filter pollution, especially hydrocarbons and metals from road surfaces. Most greenwaste-based composts can be applied to a depth of three inches. Composted biosolids should be no deeper than two inches.

If you don’t produce your own compost on-site, it should be obtained from a reputable source that guarantees high quality. Commercially produced compost quality can vary significantly due to the diverse nature of feedstock, composting processes, and maturation standards.

Using compost as a soil amendment

For native plants in your sustainable landscaping, use roughly 15 percent compost by volume to repair disturbed or damaged soils.

Clay-based soil amended with compost will lead to more productive and healthy plant growth at a lower cost than amending the same soil with the necessary 45 percent sand.  In general, poor soils that are compacted, lifeless, or subsoils should be amended with three to six cubic yards or high-quality compost per 1,000 square feet to improve soil structure,

Biosolids-based composts should be used sparingly if they are high in ammonium nitrogen.

How do you know when it’s ready to use? Your compost is ready to use when it has an earthy smell, when it’s cooled off, and when it doesn’t reheat when stirred. The color should be uniformly dark brown or even black. You shouldn’t be able to identify any of the original particles.

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

Overwatering-drought-landscaping-Conservation Corner

Check Before Overwatering Your Landscaping

Do you know if your landscaping really needs water? Even if you have waterwise irrigation on a properly timed schedule for your individual landscaping plan, it’s a good idea to make sure it’s really needed. You could be wasting water assuming it’s necessary. Appearances can be misleading.

Rely on data from an old-school method of measurement. Because soil may appear dry on the surface, stick your finger into the soil and see if the soil is wet beneath the surface. If the soil is moist up to your second knuckle, it doesn’t need any more water. Wait for another 24 to 48 hours, then recheck the soil.

If you don’t want to ruin a manicure, use a soil probe to measure the moisture in the soil to determine whether the soil needs more water.

You can also observe plant health. How vibrant are your plants? This can be tricky because sometimes the signs of overwatering and underwatering will produce similar results in plants.

Watering your plants by hand is a great way to control exactly how much water they receive and observe them closely to be sure they are flourishing in the early stages.

Watering your plants by hand is a great way to control exactly how much water they receive and observe them closely to be sure they are flourishing in the early stages. Photo: Jill Wellington/Pixabay

Underwatering symptoms include:

  • Soil is bone dry
  • Older leaves turn yellow or brown and drop off
  • Leaves are wilted
  • Leaves curl and become brittle
  • Stunted plant growth

Overwatering symptoms include:

  • Soil is constantly saturated and soggy
  • Leaves turn a lighter shade of green, or turn yellow
  • Younger plant shoots wilt
  • Leaves are green and brittle
  • Algae and mushrooms are in the soil
  • Growth is excessive

Rely mainly on objective measurements. Symptoms at both irrigation extremes can be similar. Using simple measurement tools can help ensure the correct amount of irrigation takes place without withholding needed moisture, but without overwatering and wasting resources.

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

Carefully selected trees are the most valuable addition to your sustainable landscaping. Photo: Helix Water District landscape trees

Trees: Landscaping MVP (Most Valuable Plant)

New waterwise landscaping represents a significant investment in time and cost. Trees stand out as the most valuable players in your landscape design. No other landscape plant offers greater benefits to your landscape and the environment as a whole.

Trees save energy and clean the air.  They counteract the urban heat island effect and fight climate change. Trees provide property protection and improve property values. Neighbors with more trees even have lower crime rates.

Investing in tree maintenance is vital to keep them healthy. Tree pruning should only be done for a specific reason. First, for corrective or preventative measures.  Second, to remove dead, crowded, or poorly angled branches or to reduce potential hazards. Third, to increase light and air penetration for healthy growth.

Tips from pros on pruning and thinning trees

Trees are the most valuable players in your landscape design, and you can keep them healthy by using proper pruning techniques. Photo: Benjamin Balazs/Pixabay

Trees are the most valuable players in your landscape design, and you can keep them healthy by using proper pruning techniques. Photo: Benjamin Balazs/Pixabay

Routine thinning does not always improve the health of a tree. Removing large amounts of foliage all at once can put stress on a tree’s stored energy reserves, resulting in stunted growth.

Pruning should be performed in the best season for the tree to avoid potential disease and to avoid pruning just after the spring growth flush.

There should be a purpose for each cut, as each cut into a tree can change the growth of the tree for many years to come. Improper or careless pruning can cause damage over the life of the tree. It is important to know where and how to make cuts before beginning the process.

When a tree branch is cut, it compartmentalizes the wound to protect itself. A small cut does less damage than a large cut. Waiting to prune a tree until it is mature can create the need for large cuts, which can threaten the life of the entire tree. Ongoing and regular maintenance is a must.

Call on a certified arborist to maintain your trees in optimal health. Arborists are specialists trained in the art and science of planting, caring for, and maintaining individual trees. They can identify and treat diseases before they spread to other trees. Find qualified professionals at the International Society of Aboriculture and the American Society of Consulting Arborists.

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