Conservation Corner Archives

Paul Redeker surveys displays at The Water Conservation Garden, located on the campus of Cuyamaca College. Photo: David Ogul, Water Authority

Inspiring Change at The Water Conservation Garden

July 24, 2018/in Conservation Corner, Features /by Gayle Falkenthalby Water News Network staff

Horticulture director embraces educational mission

WaterSmart landscapes are transforming San Diego County’s neighborhoods in part due to the work of Paul Redeker and his colleagues at The Water Conservation Garden in El Cajon.

“We’re a learning center, not just a place where you’re surrounded by beautiful plants,” said Redeker, who recently returned for a second run as director of horticulture and facilities the garden. “All of our exhibits are geared toward teaching. We are all about educating the public to be inspired to make changes in their lives because we’re literally at the end of the water pipeline.”

Driving that point home is a giant pipe protruding from a landscaped embankment with water trickling from its opening into a lily pond near the entrance to this one-of-a-kind, six-acre conservation showcase on the campus of Cuyamaca College.

“I love the educational element,” Redeker said. “The learning that goes on in this garden regarding low-water options is wonderful.”

‘Wonderful’ low-water options

The Water Conservation Garden feature a Native Habitat Garden, the Compost Exhibit, the Veggie Garden and the Succulent Garden. Take a free, docent-led tour the first Saturday of each month at 10 a.m. Illustration: The Garden

Opened in 1999, The Water Conservation Garden is owned by a joint powers agency comprising the San Diego County Water Authority, the Otay Water District, the Helix Water District, the Sweetwater Authority, the City of San Diego Public Utilities and Cuyamaca College. From the start, the garden was seen as an important conservation tool in a region with few natural water resources.

More than 30,000 people visit each year, and the garden’s programs reach an additional 80,000. It is the educational element that lured Redeker back. “The learning that goes on in this garden regarding low-water options is wonderful,” he said.

Born and raised on a Sonoma County ranch, Redeker earned his bachelor’s degree in ornamental horticulture, with a focus on landscape design, from Cal Polytechnic State University at San Luis Obispo. He worked at several Northern California nurseries before exploring other career interests overseas.

Redeker returned to California and was designing landscapes for a San Diego company when he fell in love with public gardens and landed a position as The Water Conservation Garden’s director of horticulture more than 10 years ago.

After five years in El Cajon, he expanded his professional expertise at the San Diego Botanic Garden, another regional showcase garden in Encinitas. “It gave me a wonderful understanding of how larger gardens operate,” said Redeker.

A constantly evolving gem of a garden

Plans are underway for new displays including an interactive irrigation exhibit, watershed exhibit, and a new outdoor classroom. Photo: David Ogul, Water Authority

Redeker returned to his “little gem of a garden” last fall, and he is thrilled with the opportunities to innovate. “We are always looking to improve the experience so that when people come back, they can see something new and fresh,” he said.

Projects under way or in the planning stages at The Water Conservation Garden include:

An interactive irrigation exhibit to help visitors understand and appreciate different types of water-saving technologies.
A watershed exhibit with a “follow the raindrop” feature that illustrates the benefits of strategic stormwater management.
More than a dozen strategically placed, drought-tolerant trees – including the Silk Oak , Blue Atlas Cedar, Sweetshade, and the Variegated Brisbane box – have been planted throughout the garden to help keep summertime temperatures in check.
An expanded indoor classroom that will more than triple capacity to nearly 100.
A new outdoor classroom, covered with a shade structure, will replace the current outdoor class space.

“The new classroom is going to be huge for us,” said Pam Meisner, the garden’s director of operations and programs. “We simply don’t have the room to accommodate demand for all of our adult-education landscaping and gardening classes.”

Among the permanent features is a Retrofit Backyard Exhibit that includes a traditional backyard lawn – complete with a depiction of a homeowner struggling to mow a greenbelt that drinks some 28,000 gallons of water annually – adjacent to a more visually appealing, and less labor-intensive garden featuring drought-tolerant plants that uses just 6,000 gallons of water each year.

“People are being smarter and much more creative with what they’re doing with their landscape,” said Redeker. “We’re seeing smarter plant choices, more hardscape, more patios, more mulch, dry streambeds and the like, and it’s making a difference.”

Beeblossom (Gaura) shrubs are a good low water use landscaping choice based on its Plant Factors rating. Photo: Water Authority

Knowing Your Plants’ Water Needs

July 19, 2018/in Conservation Corner, Features /by Gayle Falkenthal

Landscaping professionals use a resource called the Water Use Classification of Landscape Species (WUCOLS) to classify plants according to their water needs.

It might sound really complex, but it’s really useful because it breaks down the water requirements for each type of plant into four categories: Very Low, Low, Moderate, and High. These water requirements are also called Plant Factors, and they are an important tool for transitioning to a more water-efficient landscape.

Water Requirements by Plant Factors

To come up with a Plant Factor for a given plant, that plant’s water use is compared to cool season grass in a given climate zone.

Why is that? Turf is among the thirstiest of all types of plants. When you replace turf areas with climate-appropriate plants with lower water requirements, and irrigate them with more efficient systems, you can realize a tremendous amount of water savings. There is no need to turn your landscaping into a dry, brittle moonscape to do it.

Here are the Plant Factors, or PF, categories:

Plant Factor categories from high to low water use. Graphic: Water Authority

High: These plants need from 60 to 100 percent of the water needed for a grass lawn (PF of 0.6 – 1.)

Moderate: Plants need 30 to 60 percent of the water needed for a grass lawn (PF of 0.3 – 0.6)

Low: Plants need 10 to 30 percent of the water needed for a grass lawn (PF of 0.1 – 0.3)

Very Low: Plants need 10 percent or less of the water needed for a grass lawn (PF of less than 0.1)

Group Plants by PF to Irrigate More Efficiently

In the Water Authority’s Sustainable Landscaping guidebook, plant selections are color-coded to identify their water needs under this system. That approach provides an easy way to group plants by their water requirements in your landscape, so you can irrigate more efficiently.

This article was 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.

Knowing how to classify your plants by water use characteristics will help you plan your sustainable landscaping. Photo: Water Authority plant factor

Evapotranspiration: The Key To Watering Your Plants

July 11, 2018/in Conservation Corner, Features /by Gayle Falkenthal

How much water do plants really need in your landscaping?

Evapotranspiration (ET) is the process of assessing various factors to determine how much water plants use, and when they need it. ET is a quick, simple way for landscape experts to explain environmental conditions such as solar radiation (sunshine) or cloud cover. The stronger the sun’s rays, the higher the ET.

Think of plant leaves as having similar properties to solar panels. They gather energy that enables plants to transform water and carbon dioxide from the air into oxygen and sugars for growing, and for feeding soil microbes. Transpiration of moisture through leaves is a little like people sweating. It cools down the leaves. Water also evaporates from the soil itself around plants. The combined water loss from the plants and the soil together makes up evapotranspiration.

Why do you need to know this? Understanding water loss in terms of ET is helpful when you select plants for sustainable landscaping, so you choose the lowest Landscape Water Requirements; in planning irrigation; and managing the Soil Moisture Account.

Look for Four Characteristics Shared By Drought–Tolerant Plants

Do you need help identifying climate-appropriate plant choices for your new sustainable landscaping? There are four characteristics shared by drought-tolerant plants.

Stiff, Leathery Leaves: These leaves hold on to water and stay evergreen most of the year.

Silver or Hairy Leaves: Light colored leaves reflect sunlight, cooling the plant. Hairy leaves hold moisture longer and keep the plant cooled off.

Tiny Leaves: These are like tiny solar panels, easier to keep cool than one large hot surface.

Solar Tracking Leaves: These leaves seem to stand at attention in the middle of the day, straight up and down. As the day progresses, the leaves become more horizontal as the plant shifts its solar panel leaves to minimize sun exposure. Many California native plants like manzanitas have this ingenious adaptation.

The Water Authority’s Sustainable Landscaping guidebook contains a Plant List with climate-appropriate plants. They are also highlighted throughout the guidebook.

This article was 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.

As San Diego's temperatures soar, be sure your water use isn't soaring by using water resources efficiently. Photo: DaveJessica - Creative Commons License use water resources efficiently

San Diego Region Expects Sizzling Summer Heat

July 6, 2018/in Conservation Corner, Features /by Gayle Falkenthalby Water News Network staff

Water Authority offers tips to keep things cool while using water resources efficiently

The first major heat wave of summer 2018 in the San Diego region arrived Friday, and it is expected to continue through the weekend. Temperatures hit a record 111 degrees in communities including El Cajon, Escondido, and Ramona on Friday. The City of San Diego reached 93 degrees. There won’t be much relief on the beaches, as Coronado’s forecasted high on Saturday is 83 degrees.

Heat records set in San Diego and around the world

Red-hot temperatures are a worldwide trend, including in the San Diego region. The National Weather Service reports 53 of the last 56 months have been hotter than normal at the official weather station at Lindbergh Field.

San Diego’s temperatures show an upward trend overall.

All time heat records have already been set this week from Denver to Tbilisi, Georgia. Record heat is to blame for at least 33 deaths in and around Montreal, Quebec.

Whether or not the San Diego region will break its record high temperatures of 2017 this year, it is important for residents to use WaterSmart practices which help you use water resources efficiently during the peak water-use months.

The San Diego County Water Authority offers several tips for making the most of the region’s water supplies. They include:

Check your landscaping’s irrigation system

Inspect irrigation equipment to eliminate overspray. Monitor soil moisture using a spade or soil probe, and only water if the top inch of soil is dry. Irrigate turf if it doesn’t spring back when stepped on. Better yet, upgrade to a “smart” irrigation controller that automatically adjusts water times based on weather conditions. Rebates on irrigation equipment are at WaterSmartSD.org.

Water your mature trees correctly

Water mature trees like this mesquite tree slowly and deep into its roots. Photo: Water Authority

Irrigate mature trees once or twice a month using a soaker hose or drip system toward the edge of the tree canopy – not at the base of the tree. Use a hose faucet timer (found at hardware stores) to prevent overwatering. Young trees need more frequent irrigation; consult an arborist or tree-care manual for details.

Refresh your compost and mulch

Keeping a 3-inch layer of mulch around trees and plants reduces runoff, helps control weeds and protects soil from direct sunlight and evaporation. Keep mulch at least a foot away from tree trunks and several inches from the crowns of plants. Also, add compost to increase soil nutrients.

Refrigerate drinking water

Your lorikeet can get its drinking water this way. You should fill your reusable water bottles and chill them in the refrigerator for your cold drinking water. Photo Wade Tregaskis – Creative Commons License

Keep drinking water cool in your refrigerator to avoid running the tap. Use refillable water bottles instead of buying disposable plastic bottles.

Put a lid on it

Pool and spa covers reduce evaporation, lower pool heating costs and keeping out dirt and debris.

Take a gardening break from the heat

New plants need more water to get established, so wait until fall or winter for planting to take advantage of cooler temperatures and rainfall.

Watch the grass grow

Let your grass grow longer in the summer. Photo: PhotoMix – Creative Commons License

Set your mower to leave grass at least three inches high, because taller blades of grass can reduce evaporation up to 80 percent and protect your roots from heat. And don’t water during the hottest part of the day. The ground can be so hot, roots may literally cook themselves in hot irrigation water.

Treat your vehicles to an efficient car wash

Patronize car washes that recycle water and save at least 15 gallons each time. When washing at home, use a hose nozzle that shuts off when you release the handle.

Rinse your produce the right way

Rinse your fresh fruits and vegetables in a bowl, then use the water on your indoor plants. Photo: McBeth, Creative Commons License

Wash fruits and vegetables in a bowl of water instead of under a running water tap. Use the bowl of water afterward to water your house plants or outdoor container plants.

Go to summer school

Learn more tips and best practices on how residents and businesses can use water most efficiently, including WaterSmart Landscaping Videos on Demand from the comfort of your beach chair or sofa, plus information on rebates, classes and other water-saving resources to help you keep your cool on your water use this summer at WaterSmartSD.org

Create a healthy growing environment for your new landscaping with the "soil lasagna" method. Graphic: Water Authority

Cook Up A Soil Lasagna

July 4, 2018/in Conservation Corner, Features /by Gayle Falkenthal

Healthy, living soil is full of oxygen, water, and life to support your plants. Building healthy soil using layers uses a process called soil sheet mulching, or “Soil Lasagna.” If you have ever cooked lasagna, this will seem familiar. Soil Lasagna boosts healthy microbes so much that they actually cook down the organic matter and start eating old grass in your landscape as food.

Once you’ve created Soil Lasagna, all you need to do is keep it moist so the microbes will stay active. How long the process takes from start to finish depends on the kind of grass you have. When you are ready to plant, you can dig a hole right into it, cutting through any paper or cardboard that might still be there, planting in the delicious and healthy soil below.

Supply List to Create Soil Lasagna

- Shovels and rakes
- Wheelbarrow(s)
- Bins to hold removed grass and soil
- Mulch
- Landscape flags
- Painters’ paper or large cardboard sheets
- Compost, worm castings, or compost tea
- Hose with a shutoff nozzle

NOTE: If you need any permits, call DIG ALERT (8-1-1) two days in advance. Also, check with your local water agency for any local water use restrictions.

Once you have checked for permits and any water-use restrictions, you will need to remove your lawn. See our previous column on removing your lawn without killing the existing microbes. You will end up removing about six inches deep of grass and soil. You will need to haul this away. Consider renting a dumpster.

Dig a trench 8 to 12 inches deep (about one shovel depth), and 12 to 24 inches wide around any hard surfaces and building foundations. Also, complete contouring for rainwater absorption and retention and any other hardscaping such as moving or installing patios, paths and other features.

Use landscape flags to mark sprinkler heads so you can find and adjust them later.

Layers Are Key To Your Soil Lasagna

Add an inch deep layer of compost on top of the graded soil. You can also use humates (a freeze-dried compost available at specialty landscaping stores) or spray with compost or worm tea. You are adding an instant food sources and additional microbes to the soil.

Water thoroughly. Roll out your painters’ paper or cardboard. Overlap at the seams about six inches and be sure all of the soil is covered. At the hardscape borders, make a burrito of rolled paper and mulch to prevent grass from resprouting.

Water the paper, and then add another layer of compost if you wish. Rake a thick, six-inch larger of mulch over the paper and compost. Now you’re seeing why this is called a Soil Lasagna.

Water again thoroughly. The mulch will absorb a lot of water before it becomes soaked through.

You can plant right through the Soil Lasagna layers. If you can wait, the soil will develop more healthy microbes for new plants, but you can plant right away if the grass has been removed.

Finally – step back and savor your hard work!

This article was inspired by the 71-page Sustainable Landscapes Program guidebook available at SustainableLandscapesSD.org. Hardcopies are available free of charge at the Water Authority’s headquarters, 4677 Overland Ave., Kearny Mesa. The Water Authority and its partners also offer other great resources for landscaping upgrades, including free WaterSmart classes at WaterSmartSD.org.

The Right Way to Remove Your Lawn

June 27, 2018/in Conservation Corner, Features /by Gayle Falkenthal

If you have made the decision to replace your thirsty, water-guzzling grass, you need to plan your grass removal process carefully to ensure you leave healthy living soil ready for new landscaping in its place.

Here’s how to do it:

First, keep your grass moist until you remove it. Don’t withhold irrigation and let it turn brown as it dies off. Healthy microbes in your soil will die off along with the lawn. You want to work with those microbes to help create healthy soil for your new plants. It’s also a lot easier to remove fresh, moist grass than to try and pry out dead dry grass and weeds in hard dry soil.

Keep your soil microbes healthy to support your new landscaping

Along the same lines, don’t “solarize” your landscaping in the effort to remove your lawn. Solarizing is sometimes used as a way to remove grass with chemicals. It uses a covering such as a heavy black plastic tarp to broil the lawn at high temperatures using sunlight and kill it. But that process kills everything, including healthy microbes you need for healthy soil. Yes, you can replace them with compost, but you will need to invest in a lot of compost to restore the good microbes after you’ve removed the grass by solarizing.

Solarizing also backfires because sterilized soil is ideal for weeks. The moment you remove the plastic, opportunistic weeds will move in fast to try and take over the ground. It isn’t because you failed to kill the weed seeds in the soil. New weeds can arrive in a flash, and there is nothing to prevent them taking over.

Avoid compacting or tilling your soil when removing old turf

Avoid compacting your soil. If you use heavy equipment to remove your old turf, the weight of the equipment will compact the soil underneath. Try to minimize the use of heavy equipment and use walk-behind equipment with hand tools where possible, reserving the use of a tractor or scraper only where necessary.

Avoid tilling your soil. Tilling soil breaks up and kills your soil microbes. Without the microbes, you’re guaranteed to have those weeds pop up for a long time until new soil microbes develop.

When removing your grass, protect your trees. If you want to preserve your healthy trees while removing your lawn, you need to be careful with their roots. Don’t use any heavy equipment to remove turf around your trees. Avoid the entire area under the canopy of the tree’s branches. Tree root structures extend all the way out to the drip line at the edge of the leaves. Keep your trees well-watered during the removal process to help minimize root shock.

Guard against shock to trees from reduced irrigation

When your new sustainable landscaping is installed, your previously existing trees may go into shock when irrigation is reduced overall in your garden. After all, this is one of the reasons for removing your lawn. Pay special attention to keeping the trees watered during the first year after your grass is removed, even if you remove the surrounding original irrigation.

A good way to hand-water trees is to punch holes in a five-gallon plastic bucket. Fill the bucket, set it down at the edge of the tree canopy, and let the water slowly seep into the ground. Repeat the process three to four times to water your beautiful mature trees. This mimics the natural rainfall Mother Nature provides.

More About Mulch You Need To Know

June 20, 2018/in Conservation Corner, Features /by Gayle Falkenthal

When using mulch in your landscaping, how much mulch do you need? It depends on what job you want it to perform.

To hold in moisture and keep down weeds: Use three to six inches of mulch on top of the soil.

To maintain planting beds: Maintain two to four inches of mulch on beds at all times.

Remember to keep mulch one to six inches away from plant stems. Mulch can cause plants to rot.

How Much Mulch Do I Need?

A few simple measurements and calculations will help you determine your mulch needs. Graphic: Water Authority

You first need to know these numbers:

Square footage of your landscaping
Thickness of your mulch cover in inches

Then take your square footage, multiplied by mulch thickness, and divide it by 12. This will give you your amount of mulch in cubic feet.

For instance, 891 square feet of land, multiplied by one inch of mulch, divided by 12 = 74.25 cubic feet of mulch.

Avoid These Mulch Types Around Plants

Inorganic mulches don’t decompose to feed soil microbes and keep your plants and garden healthy and thriving. There are also some organic mulches containing dyes or other chemicals. Other mulches, such as shredded redwood, take a very long time to break down. These are the types of mulches you should use only in areas without plants, such as in pathways or dry decorative areas:

Shredded redwood
Dyed wood mulch
Decomposed granite
Gravel
Rubber pellets

Vista Irrigation District Announces WaterSmart Landscape Contest Winner

June 18, 2018/in Conservation Corner, Features /by Gayle Falkenthal /Vista Irrigation Districtby Vista Irrigation District

Vista, Calif. – The Vista Irrigation District board of directors recognized one of its customers for their entry in the district’s WaterSmart Landscape Contest.

The contest recognizes outstanding water-wise residential landscapes based on the criteria of overall attractiveness, appropriate plant selection, design, appropriate maintenance, and efficient methods of irrigation.

Bill and Rachel Williams received the “Best in District” award. During the height of the drought, the
Williamses decided to replaced their water-intensive front and back lawn with a water-efficient landscape. After
hiring professionals to remove over 2,500 square feet of grass and install drip irrigation, the Williamses designed
the layout and chose the water-wise plants themselves. By adding fun elements, such a horseshoe pit and outdoor
seating area surrounding a fire pit, the Williamses transformed unused space into a backyard with utility.

The Williams’ backyard prior to their WaterSmart landscaping project. Photo: Vista Irrigation District

The result was an eye-catching design incorporating decomposed granite, cactus and splashes of vibrant color from the aloe
and agave families, including Coral Aloe as well as Foxtail and Century Agaves; plant selection also included
Aeonium, Rosemary, Senecio and Firestick.

WaterSmart project creates new backyard haven for homeowners

The Williamses “couldn’t be happier with the results”, and their WaterSmart project turned their water
thirsty lawn into a low maintenance, low cost and water efficient haven where they can relax and enjoy a game of
horseshoes.

Another view of the new WaterSmart landscaping installed by the Williams family of Vista. Photo: Vista Irrigation District

With a majority of residential water use in San Diego County attributed to watering landscapes, regional
water efficiency efforts focus on outdoor water use. By showcasing their beautiful landscape in the WaterSmart
Landscape Contest, these district customers provide other homeowners with ideas and incentives to reduce their
own outdoor water use by installing attractive and efficient water-wise landscaping.

“Replacing your lawn with a WaterSmart landscape is a beautiful way to save water and money at the same
time,” said Brent Reyes, water conservation specialist for the district.

Vista Irrigation District part of effort to showcase residential water-wise landscapes

The district joined eleven other local agencies that held landscape contests this year, providing an
opportunity to showcase residential water-wise landscapes throughout the region. Participating agencies (besides
Vista Irrigation District) include Helix Water District, Olivenhain Municipal Water District, Otay Water District,
Padre Dam Municipal Water District, San Dieguito Water District, Sweetwater Authority, Vallecitos Water District,
California American Water, and the cities of Escondido, Oceanside and San Diego.

For more information about the contest and to see more examples of WaterSmart landscaping, visit
www.landscapecontest.com. Visit the district’s web site (www.vidwater.org) or call (760) 597-3107 to find out
more ways to save water.

The Vista Irrigation District is a public agency governed by an elected five-member board. The district
provides water service to more than 133,000 people in the city of Vista, and portions of San Marcos, Escondido,
Oceanside, and unincorporated areas of San Diego County.

While compost and mulch may seem interchangeable, they have distinctly different uses in your sustainable landscaping. Photo: Water Authority Compost vs. Mulch

Compost vs. Mulch: What’s the Difference?

June 13, 2018/in Conservation Corner, Features /by Gayle Falkenthal

Compost and mulch may seem like interchangeable terms for the same thing. But they are two different things with different uses in your landscaping.

Compost is a soil amendment. It is made of organic matter such as food scraps, landscape debris, or livestock manure that have already been partially consumed and mostly decomposed by microorganism. You cannot tell the original source of compost. Good quality compost brings the helpful “OWL” formula of oxygen, water, and life together in one package.

Mulch is a soil topping. Mulch can be either organic or inorganic material that covers soil. The original recycled debris source of mulch is often identifiable. Mulch can be made from organic sources (grass clippings, leaf and yard litter, shredded wood trimmings) or inorganic sources such as gravel or decomposed granite (sometimes called “DG” for short).

The microbes in healthy, biologically diverse mulch will “knit” the organic material together, forming a thick blanket. This mulch cover protects the soil and plant roots from temperature swings, retains moisture by slowing down evaporation from the surface of the soil, and keeps weeds from sprouting by reducing sunlight penetration to the soil surface.

How to Use Compost

You can buy commercially produced compost, or you can make it at home. The compost-making process, or composting, involves creating the optimal conditions for the microbes to do their transformative work.

When compost looks like soil, you can work it directly into the soil. When compost is more coarse or has visible bits of the original materials, the most likely it is used on top of the soil instead of as an incorporated soil amendment worked in.

Compost works in several ways. The compost itself contains particles that improve soil structure. Next, as compost decomposes in soil, it encourages the formation of soil macroaggregates. These macroaggregates are composed of existing soil particles and decomposed organic matter, which combine to create a more stable and better-functioning soil structure.

How to Use Mulch

Mulch always stays on the surface of your soil. It is never worked in. Recycled organic material is the most effective type of mulch, because it builds soil structure over time and provides a durable, protective barrier. The smaller the debris pieces are and the more mixed the organic pieces are such as leaves with wood chips, the faster it decomposes. When building your soil, small mixed mulch is best.

Composted materials, especially coarse composts such as decomposed granite, can also be used as mulch. Artificial and inorganic mulches (DG, gravel, rubber chips) are mainly decorative. They do not contribute to soil life or plant health. They are best used in limited applications, such as creating natural pathways.

Use a soil probe to test how well irrigation dispenses into your landscape. Photo: Courtesy University of Florida/Creative Commons use soil probe

Take the Test: Use a Soil Probe

June 6, 2018/in Conservation Corner, Features /by Gayle Falkenthal

If you want to create a healthy, thriving landscape full of beautiful plants, you need to know how to use an important soil management tool: a soil probe.

Irrigation is essential to keep your landscaping green and growing. But to do so, you need to know as much as possible about your soils. One way is to use the Jar Test.

You should also use a soil probe. A soil probe lets you determine a lot more information about the soils in your landscaping. It helps you learn whether your irrigation water is successfully reaching the roots of your plants, or even if it soaks in too deep past the reach of plant roots.

Without a good picture of your soil profile, you can’t answer questions about effective irrigation. Variability across your landscape could result in different types of soils in different areas, or in soil layers extending different depths.

A good soil probe will help you figure out when irrigation water has reached the right depth for landscaping plants. It is a simple process with the right tools.

When your soil is moist, a soil probe should go into the ground easily. Your soil probe will stop when it hits hard, dry dirt and won’t go further.

How Low Should Your Irrigation Go?

If your probe stops, it could be hitting a rock, so you may want to reposition it a few inches away and try again. If you are confident you’ve just hit dry soil, put your fingers around the probe at the soil surface, and pull it out. Measure the depth in inches to learn how deep your irrigation penetrates the soil.

To properly irrigate your plants, understand the depth of their roots. Trees send their roots much deeper into the soil than shrubs, and shrubs have deeper roots than bedding plants like annual and perennial flowers or vegetables.

Most plants will do fine as long as the top foot of soil is filled with water when you irrigate. Shrubs should be irrigated to a depth of two feet, and trees irrigated to a depth of three feet.

You can purchase a soil probe at any general hardware story or gardening center. A basic soil probe costs between $30 and $80, but there are high-tech probes costing up to $300.

This article was inspired by the 71-page Sustainable Landscapes Program guidebook available at SustainableLandscapesSD.org. Hardcopies are available free of charge at the Water Authority’s headquarters, 4677 Overland Ave., Kearny Mesa. The Water Authority and its partners also offer other great resources for landscaping upgrades, including free WaterSmart classes at WaterSmartSD.org.

You are now in Conservation Corner Features category.

Horticulture director embraces educational mission

‘Wonderful’ low-water options

A constantly evolving gem of a garden

Water Requirements by Plant Factors

Here are the Plant Factors, or PF, categories:

Group Plants by PF to Irrigate More Efficiently

Look for Four Characteristics Shared By Drought–Tolerant Plants

Water Authority offers tips to keep things cool while using water resources efficiently

Heat records set in San Diego and around the world

Check your landscaping’s irrigation system

Water your mature trees correctly

Refresh your compost and mulch

Refrigerate drinking water

Put a lid on it

Take a gardening break from the heat

Watch the grass grow

Treat your vehicles to an efficient car wash

Rinse your produce the right way

Go to summer school