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Matilija poppies, or Romneya coulteri, have the largest flower of any poppy. It's native to dry, sunny areas from California to Baja and are good choiices for successful sustanable landscaping. Photo: Kimberly Rotter / Pixabay

How to Pick Your Plants for a Successful WaterSmart Landscape

Once your WaterSmart Living Landscape design starts coming together, pick your plants for each water-use category to ensure you meet your WaterSmart water conservation goals. Focus on local native plants or plants from similar climate regions.

Let this video help you choose the right plants for our Mediterranean climate

 Once you’ve chosen your plant types, there are additional important considerations.

Design for mature plant size: Allow enough space for the plants you select to grow to their full size to avoid overcrowding or the need for excessive pruning.

Growing conditions: Select plants suited for your microclimate, soil type, and drainage to achieve optimum plant growth.

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

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

Tree placement: Typically, a planting design will include a tree or two for shade. Placing a deciduous tree on the south or west side of your home will shade your house during the summer to keep it cool and allow more light and sun exposure in the winter. Keep trees at least 10′ from foundations. In fire hazard areas, trees should be placed, so the mature canopy is at least 10 feet away from any structures.

Shrub placement: Shrub and groundcover planting is typically designed with various heights. Medium size (three to four foot) shrubs are usually placed closer to the house to create a “foundation” or backdrop. Smaller shrubs are then placed in front of the foundation planting and low groundcovers in the area closest to the sidewalk or street.

Accent shrubs can provide a unique texture, color, or flowers. Place them so they provide interest and focus views on locations in the landscape. Highlight your entrance walk with special accent plants. This places a higher emphasis on your entry, which is where you want visitors to be directed.

Be bold and have fun. Don’t be afraid to express your individual tastes.

Using water features and higher water use plants

Determine water use before choosing plants for your new sustainable landscaping. Photo: San Diego County Water Authority

Water has been a precious resource throughout history in arid regions of the world. This perspective has been integrated into Mediterranean landscapes by using water only in the most important areas.

If you have some high water use plants you particularly want to include, they can be used. Strive to include no more than 10% high water use plants or water features in your landscape, so choose carefully.

Hyrdozones and water-efficiency

If you choose to include plants not classified as very low or low water use, be sure to group these moderate or high water use plants together. Grouping plants of similar water use together, known as planting in hydrozones, makes it easier to irrigate efficiently by letting you concentrate additional water only where it is needed.

Higher water use plants should be on a separate irrigation valve so you can water them differently than the rest of the garden.

Mediterranean landscapes also historically used water features for a pleasant and calming sound. The water area of the fountain will lose water at about the same rate as cool-season turf grass or another high-water use plant. By minimizing the square footage of open water, a water feature can fit well into the WaterSmart landscape.

Minimizing turf use

Limit the amount of turf in your design as much as possible. If you choose to incorporate turf, consider a warm-season turf that uses less water than traditional cool-season turf. Warm-season turf such as Hybrid Bermuda or UC Verde Buffalo Grass thrives in the hot months of the year and naturally go dormant in winter. Another less thirsty grass to consider is Carex praegracilis or California Field Sedge.

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WaterSmart Living-Logo-San Diego County Water Authority

(Editor’s Note: The San Diego County Water Authority and its 24 member agencies offer programs, resources, and incentives to improve water-use efficiency for residential, commercial, and agricultural users. WaterSmart choices are a way of life in the region. Stay WaterSmart San Diego! For more water-use efficiency resources, go to WaterSmart.SD.org.)

Everett’s California Fuchhia is an example of a plant that doesn't like to have wet feet, meaning roots sitting in water. Photo: Wikimedia Commons

Get Down to the Roots Of Your Landscaping

Plants don’t literally have feet to take them on a walk, but landscapers often refer to a plant’s “feet,” or their roots. Plants like – and need – water on their roots to thrive. While plants absorb water through their leaves, it’s not very efficient due to evaporation. Roots absorb the bulk of water a plant needs to thrive through small root hairs, which are thin-walled outgrowths of the plant’s epidermis. The film of water surrounding soil particles provides its irrigation supply.

Horticulturists refer to plant roots in soggy soil as “wet feet.” Plants that can thrive without too much water on their roots are said to have “dry feet.”

The same way people don’t like waterlogged, soggy feet in wet socks on a cold day, plants don’t welcome their roots sitting in standing water. Most plants don’t grow well with excessive moisture at the roots. It can cause rot and other diseases. Very few plants grow in wet areas, and while it isn’t a common problem in the arid Southwestern United States, plants might end up in standing water in poorly drained landscaping.

Five Recommended Plants That Tolerate Wet Feet

The California Native Iris (Iris douglasiaria) is a plant that doesn't mind having "wet feet," or damp roots. Photo: Wikimedia Commons wet feet

The California Native Iris (Iris douglasiaria) is a plant that doesn’t mind having “wet feet,” or damp roots. Photo: Wikimedia Commons

  • Coyote Mint (Mondarella villosa)
  • California Gray Rush (Junous patens)
  • Joaquin Sunflower (Bidena laevis)
  • Deer Grass (Muhlenbergia rigens)
  • California Native Iris (Irish douglasiaria)

Five Recommended Plants That Prefer Wet Feet

Everett’s California Fuschia is an example of a plant that doesn't like to have wet feet, meaning roots sitting in water. Photo: Wikimedia Commons Roots

Everett’s California Fuschia is an example of a plant that doesn’t like to have wet feet, meaning roots sitting in water. Photo: Wikimedia Commons

  • Bluff California Lilac (Ceanothus maritmus)
  • Everett’s California Fuschia (Epilobium canum)
  • Sunset Manzanita (Arctostaphylos Sunset)
  • Hairy Awn Muhly (Muhlerbergia capillans)
  • Blonde Ambition Blue Grama (Boutelous gracilis)

Get advice from the local garden center or horticulturalists familiar with your area for other good choices. In general, native plants match well to similar nature conditions in the 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.

Set yourself up for landscaping success by building the best foundation in your soil structure. Photo: walkersalmanac/Pixabay healthy soil

Take a Test to Determine Your Soil Type

If you put a shovel into the ground in San Diego County, you are likely to encounter the region’s impermeable soil structure. Impermeable soils are defined by poor infiltration areas. This means water doesn’t flow through the soil to replenish groundwater, because the soil is too dense.

Having impermeable soil also means water does not soak evenly into the ground or flow through living soil to plants in a healthy way. No matter where you plan your landscape, you should concentrate on improving your soil structure. That will help you irrigate more efficiently and cost-effectively, and your plants will receive the nutrients and water they need to flourish. It is relatively easy to improve your soil structure, but first you need to determine what kind of soil you have.

Particle size matters

The three basic types of soil are:

Clay: Soil made up of the smallest particles
Silt: Soil made up of a mixture of particle sizes
Sand: Soil made up of the largest particles

In general, sandy soils drain faster than clay soils, because there is more space between the larger particles. Soil structure also influences the quality of the soil. Lifeless, compacted, sandy soil will not absorb water, while healthy clay soil will be more sponge-like, holding and releasing water. The “best” soil – an even blend of sand, silt and clay – is called loam.

Find your soil structure by testing your soil

Some tests can be done onsite to figure out what kind of soil you have. Others might require lab analysis. Certain other conditions require specialized tests, such as soil used for food production or soil receiving a lot of storm water.

You can test your home landscaping soil yourself using a “Jar Test.” This is a fun project to do with kids or as a family.

Use this graphic as an example to compare your jar to. Aim to get the most even distribution, as shown with the loam jar. Image: Water Authority

Use this graphic as an example with which to compare your jar. Try to get the most even distribution, as shown with the loam jar. Image: San Diego County Water Authority

How to do the “Jar Test”

  • Use a one-quart glass container.
  • Add one cup of soil from the garden. You can select one area or take samples from several areas and blend them together.
  • Add three cups of distilled water.
  • Close the jar and shake it until all the soil solids are suspended in water. Put the jar on a shelf and wait 24 hours.
  • If the container is still cloudy, wait another 24 hours. After 48 hours, the soil layers should be settled on the bottom.
  • Measure the layers in proportion to each other, with the total adding up to 100%. Sand will be on the bottom, silt in the middle, and clay on top.
  • Refer to the graphic to determine your soil type, based on the proportions of sand, silt, and clay. Which jar does your home sample look most like?

Now you can work to improve your soil condition, providing the best possible foundation for your landscaping plants and the most efficient irrigation.

The San Diego County Water Authority and its partners also offer other great resources for landscaping upgrades, including free WaterSmart classes at WaterSmartSD.org.