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Grouping plants together by water needs by matching microcliimates creates efficient irrigation. Photo: Water Authority

Microclimate Matching in Your Landscaping Plan

Earlier in our Conservation Corner series, we described how to map the different types of microclimates present in your landscaping. Using this information helps homeowners arrange plants in a new sustainable landscape. For the most efficient water use, plants should be grouped together with similar water needs according to their preferred microclimate.

In nature, plants that like lots of water are found along the banks of a stream, or grouped together at the base of a depression. Plants that need fast-draining soils so roots don’t rot might be found on hillsides. Plants that love lots of sunshine won’t grow in the shade of a tree.

Follow The Microclimate Map

Look to the Microclimate Map for smart guidelines on choosing landscape plants. Consider this example yard with three identified microclimates:

  • A front yard in full sun most of the day.
  • A moist depressed area in full sun. This area will retain moisture more than the rest of the yard, so you could use this area for rain catchment. Raise hillside areas surrounding the depression and allow them to drain freely.
  • A shady area under the canopy of a neighbor’s large tree.

Three Different Plant Neighborhoods

Areas of your landscaping under large shade trees become individual microclimates. Photo: Ken Lund/Creative Commons License

Areas of your landscaping under large shade trees become individual microclimates. Photo: Ken Lund/Creative Commons License

When selecting landscaping plants, the yard in this example will require at least three different groupings of plants.

  • Sun-loving plants that prefer their roots dry and in fast-draining soil
  • Sun-loving plants tolerant of wet feet in winter months, which thrive in heavier clay soils
  • Plants tolerant in dry shaded areas

A final consideration before heading to the local nursery or garden center: how will you irrigate your plants?  Check the Plant Factors for each of the plants to make sure their water needs are all similar in each area. A previous Conservation Corner feature has information about Plant Factors.

Plants Speak Latin

Many plants have similar common names in English. Shopping for plants by their common names can lead to confusion between two very different plants. Instead, the best way to shop for plants is to use the Latin name. This reduces any miscommunication and any surprises in your landscaping. 

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.

Learn to match plant choices to your microclimate map. Photo: Charlie Neuman, Water Authority

How to Choose Plants for Landscape Microclimates

Every garden has completely different cultivation characteristics, even those located in the same general climate zone. For example, there will be areas where plants will flourish.

Numerous features affect your growing conditions. Structures, walls, fences, and other plants can affect the amount of sun and shade in a garden. There can be hills and hollows in your front yard that may collect cold air. Or, because your property is sloped, you don’t get frost when your neighbors do.

Individual microclimates may differ significantly from the general climate of an area. To be sure you match the right plant choices to your conditions, you need to identify and map these microclimates. Start by walking around your property at different times of day. Observe conditions and take notes.

Choose plants that will thrive

Determine which plants will work in your new garden, and which should be removed or avoided. Outline the canopy area of the plants being retained. Note the name, general size, and health of the plants.

Do any of these plants seem “unthirsty?” Many plants can thrive on less water when they are well established, with deep healthy roots. Old rose bushes and large shade trees are two good examples. These drought-tolerant plants are worth keeping if possible, especially if they are mature.

Note sun and shade patterns

Different areas of your landscaping are affected by shade, moisture, and temperature, creating a variety of microclimates. Photo: Water Authority

Different areas of your landscaping are affected by shade, moisture, and temperature, creating a variety of microclimates. Photo: San Diego County Water Authority

Mark the areas that receive sun all day, and areas that are shaded all or part of the day. Also note which areas receive only partial sun, or a few hours of direct morning sun, midday sun, or late afternoon sun.

In choosing landscaping plants, make sure to select those that are appropriate to the sunlight patterns of the garden. Plants marked as “full sun” will not be happy in full shade, and vice versa. Don’t work against their requirements.

Group plants for similar needs

Group plants with similar water requirements together. Make sure plants with different water needs are not combined. Some sun-loving plants have moderate water needs, and some have very low water needs. If these are mixed together, one will always suffer if the watering routine works for the other types. 

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.

Waterwise Tree Choices for WaterSmart Landscaping

Trees are the single most valuable addition to your waterwise landscaping. Trees create improved water quality, resulting in less runoff and erosion. They also improve air quality and provide habitat for insects, birds, and animals. Healthy, mature trees are so beneficial, they can add an average of 10% to a property’s overall value.

When thoughtfully placed around buildings, the cooling and insulation created by a tree’s canopy can reduce air conditioning needs by 30%, and can save 20-to-50% of the energy used for heating.

 

Olivenhain Municipal Water District’s 2020 WaterSmart Landscape Contest winner Laura Lisauskas redid her family’s street-facing sloped side yard. Photo: Olivenhain Municipal Water District

Protect Your Hillsides and Slopes 

San Diego County features many native canyons, and many homes are located in proximity to a native canyon. Native canyon hillsides near your home should not be disturbed. The more you can adapt your home’s landscaping to Nature’s landscaping, the healthier and more low maintenance it will be.

Your home may have been built on canyon slopes leveled or filled. When planting in previously disturbed or built slopes and hillsides, choose low-water use plants and trees, especially deep-rooted native plant species. Climate-appropriate plants with strong root structures are the best choices. Their powerful root systems can help hold your soil together.

Coarse compost and mulch can be applied directly to hillside and slope surfaces, providing protection from the force of rainfall and shading exposed soils, if your slope is gentle with a 33% grade or less. With occasional and gentle irrigation, mulch will “knit” together.

Compost blankets are another type of erosion control mat applied to the soil surface to protect and preserve it. They can be used alone, with coir mats or other organic-engineered material with biodegradable grids for stabilization. Mats allow water to penetrate through to the underlying soils while retaining loose soil and debris, preventing erosion. You can plant right through them, or use pre-seeded products.

Irrigation tips to help preserve hillsides

Be sure your irrigation plan takes into account hills and slopes to prevent wasting water and erosion. Photo: Pixabay

Prepping Hillside for planting

When preparing a hillside for planting, plan your irrigation before doing any work. Low-volume rotating spray heads are ideal for sloped areas, if the space is large and the groundcover is uniform. Inline emitter drip tubing can also be effective, especially for wider-spaced shrubs and trees.

Water can be applied in repeated short periods over the course of 24 hours so it can be fully absorbed between application times. Runoff, erosion, and efficient deep watering should be factored into all landscaping plans, but especially for hillsides.

NOTE: When using a drip irrigation system, emitters should be placed above the plant basin. Spray systems should have check valves in all lower heads to avoid low point runoff. Irrigation for the top of the slope and bottom of the slope should be on separate valves.

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.

Scotch broom's blooms are pretty, but it is a non-native invasive species and should be avoided. Photo: Armen Nano/Pixabay

Five Pushy Plant Pests To Avoid

San Diego County’s mild Mediterranean climate allows nearly any type of plants to flourish with adequate irrigation. But when non-native plants are planted alongside native plants, they do their best to take over.  These are plant pests. The worst of them overrun valuable native plant species. They drain limited rainfall and soil nutrients away from native plants which have developed the ability to better manage limited resources. The natives are not as aggressive and can’t compete with the non-native bullies.

Public enemies of your landscaping

Brazilian pepper trees are invasive with damaging roots. Photo: Sabine Schmidt/Pixabay

Brazilian pepper trees are invasive with damaging roots. They are non-native plants you should avoid in a watersmart landscape plan Photo: Sabine Schmidt/Pixabay

Plant pests

You may have planted a few of these common choices in your landscaping without knowing it. They are still sold commercially. These non-natives take up too much space to co-exist with native low-water use plants. If your landscaping gives pushy plant pests a home, remove them at the soonest opportunity.

  • African Fountain Grass
  • Periwinkle
  • Brazilian Pepper Tree
  • Scotch Broom
  • Mexican Feather Grass

Very few non-native specific offer any benefits to the San Diego region’s environment. Local animals and insects prefer native species for food and habitat. Invasive species should also be removed from commercial nursery stock, and shouldn’t ever be planted in the first place. You can help weed them out by removing them.

How to identify non-native plants

The California Invasive Plant Council maintains a list of invasive plants that cause problems throughout the state. This list only addresses plants that are a problem and may miss regional problems. For a list, visit the Plant Right website.

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.

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

Soil Lasagna Cooks Up A Tasty Landscape

Healthy, living soil is full of oxygen, water, and life to support your plants. This is the food your plants need to consume for good health. Creating healthy soil in layers is referred to as soil sheet mulching, or “soil lasagna.” It isn’t too much different than cooking a pan of lasagna in your kitchen.

Soil lasagna increases healthy microbes so much, they actually cook down the organic matter and start eating up old grass in your landscape as food.

All you need to do to encourage the active benefits of soil lasagna is keep it moist. The length of time for soil lasagna to provide the maximum benefits start to finish depends on the kind of grass you have.

Supply list to create your soil lasagna

With just a little investment of time and effort, you can create the healthiest foundation for your new landscaping. Photo: Goumbik / Pixabay

  • 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: Consider first whether you need any digging permits. If yes or you aren’t sure, call DIG ALERT (8-1-1 or  800-422-4133) two days in advance. Check with your local water agency for any local water use restrictions.

Once you have checked for permits and any water use restrictions and remove your lawn, you’re ready to get started. Remember, use healthy removal methods to set your landscaping up for success. Expect to remove and haul away about six inches deep of grass and soil. Rent and fill a dumpster which can be picked up and disposed of responsibly later.

Dig a trench eight to 12 inches deep, about one shovel depth, and at least 12 to 24 inches wide around any hard surfaces and building foundations. You need to complete contouring for rainwater absorption and retention and any other work to hardscaping such as moving or installing patios, paths, and other features.

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

Layers supply the magic

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

Create a healthy growing environment for your new landscaping with the “soil lasagna” method. Graphic: San Diego County Water Authority

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 it should seem obvious why this is called a Soil Lasagna.

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

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 into the delicious and healthy soil below. Allow as much time as you can so your soil develops more healthy microbes for your new plants. But you can plant right away if all grass has been removed and you’re short on time.

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.

Helix Water District-Demonstration Landscape-WaterSmart

Helix Water District Demonstration Landscape Blossoms

The plants are thriving at Helix Water District’s demonstration landscape just eight months after the project was completed. The WaterSmart plants at the District’s administration office in La Mesa beautify the neighorhood while inspiring people to install sustainable, WaterSmart landscaping.

“Everything is growing in beautifully,” said Helix Water District General Manager Carlos Lugo. “We started with smaller plants to reduce costs and planned for growth. We’re happy to share this resource with our customers and community.”

Demonstration landscape includes water-wise gardens

The demonstration landscape includes three unique water-wise gardens on the streets around the building, including a Mediterranean garden on University Avenue, a desert landscape on Lee Avenue and a California native landscape along the building’s main entrance on Quince Street. Each garden started with smaller plants of varying colors, flowers and textures.

Helix Water District-Landscape-WaterSmart-Lee Ave

Desert landscape on Lee Avenue at Helix Water District in La Mesa. Photo: Helix Water District

“The grasses in our native garden are filling in the mulched areas, creating a soft meadow-like appearance,” said Lugo. “We are also seeing the canopies of the Palo Verde trees expanding, and underneath, the succulents and agaves are blanketing the hillside, filling the landscape with color and texture.”

Helix Water District-Landscape-WaterSmart-Grasses

Grasses create a meadow-like appearance in some of the Helix Water District demonstration landscape gardens. Photo: Helix Water District

Plants provide wildlife habitat

The plants in all three of the gardens are adapted to San Diego’s climate and need half to a fifth of the water that a traditional lawn needs. In addition to requiring less water, WaterSmart landscapes also require less maintenance and provide habitat for local wildlife like honeybees, birds and butterflies.

In each garden, plant markers provide the name of each plant and a QR code, which when scanned with a smartphone, provide each plant’s name, sun and water needs, mature size and photo.

Customers can also use the district’s interactive webpage to make a list of their favorite plants and download each garden’s design plan. Information on efficient irrigation and rebate programs is also available.

Helix Water District-Landscape-WaterSmart

Native, water-wise plants thrive on Quince Street in one of the Helix Water District gardens. Photo: Helix Water District

The project was completed in June 2020 and partially funded through a grant from the Metropolitan Water District of Southern California.

Helix Water District provides water treatment and distribution for 277,000 people in the cities of El Cajon, La Mesa and Lemon Grove, the community of Spring Valley and areas of Lakeside – east of downtown San Diego. Helix is also a founding member of The Water Conservation Garden, a nearly six-acre water-wise demonstration garden in El Cajon.

Rebates for WaterSmart Irrigation Devices

Rebates for WaterSmart irrigation devices are available in San Diego County to help property owners reduce expenses by improving water efficiency.

The rebates, offered for a limited time by the San Diego County Water Authority, provide significant savings on devices for outdoor landscapes.

Vibrant pink, orange, purple and red succulents are interspersed among lush rosemary and lavender bushes in this award-winning landscape makeover in Santee. Photo: Padre Dam MWD

Bright Ideas Bring Padre Dam MWD Landscape Contest Winner to Life

Santee homeowners removed grass, replaced the turf with a colorful, WaterSmart landscape, and won a landscape makeover contest too.

Melissa and Josh Perrell’s new landscaping at their Santee home is bursting with bright colors. Vibrant pink, orange, purple and red succulents are interspersed among lush rosemary and lavender bushes. Even more impressive, it didn’t take a single drop of irrigation over the past year to keep it thriving.

The Perrells makeover project was selected by Padre Dam Municipal Water District as its 2020 Landscape Makeover Contest winner.

The Perrells landscaping prior to its makeover. Photo: Padre Dam MWD landscape

The Perrells landscaping prior to its makeover. Photo: Padre Dam Municipal Water District

The Perrells decided to remove their lawn about two years ago. They wanted a low-water option that would look healthy year-round and require little maintenance. They were tired of spending time mowing it and using large amounts of water to keep the grass alive only to see it get brown during summer months.

The couple learned about the Turf Replacement Rebate Program and applied for the program. To remain within the budget provided, they decided to tackle the installation themselves. This gave them the opportunity to design their own landscape, support local businesses, and choose their own plants. The rebate is now up to $3 per square foot.

The Perrells chose easy care plants they would not have to prune or maintain. Photo: Padre Dam MWD landscape

The Perrells chose easy care plants they would not have to prune or maintain. Photo: Padre Dam Municipal Water District

“We chose plants that were hardy so we wouldn’t need to replace them or do too much maintenance,” said Melissa Perrell. “We also incorporated rosemary and lavender because we think it’s neat to be able to cook with and use the plants that you have.”

One week to a beautiful new watersmart landscape

The project took one year from start to finish. Photo: Padre Dam MWD

The project took one year from start to finish. Photo: Padre Dam Municipal Water District

After planning and designing their dream front yard, the Perrells spent four days removing their turf, installing rocks, installing irrigation, planting, and laying mulch.

They used a local nursery to select plants that fit their style and budget. By working straight through the process, their landscape completely transformed in less than a week. Their DIY cost-saving approach meant that they were reimbursed for 100% of the cost of their new front yard through the rebate program.

The Perrells enjoy compliments from Santee neighbors on their new landscape design. Photo: Padre Dam Municipal Water District

Melissa Perrell loves the low-maintenance needed to keep the new landscape looking its best with no pruning or trimming, and the different heights and colors of the plants. While they have a drip irrigation system in place, the Perrells were able to turn it off and let their landscape be completely watered naturally last year. They recently turned the system on again as the weather began to heat up at the end of June.

“It’s cool that it was something we were able to do together,” said Melissa Perrell. “It’s fun because our neighbors watched us put it in and now when we see them they say ‘Your yard’s looking really nice!'” Read more

Helix Water District Creates WaterSmart Demonstration Landscape

Helix Water District recently completed a new demonstration landscape outside of its administration building in La Mesa. The project is intended to inspire and educate the surrounding communities to install WaterSmart landscaping, and it serves as an example that residents can use to help design their own landscaping.