Moving both irrigation and our limited natural rainfall through your yard into storage areas via the use of various landscaping features borrow Mother Nature’s engineering. This is especially important during hot, dry summer months. If your yard is perfectly flat, you must move soil and features around to create more water-retaining contour areas.
Moving both irrigation and our limited natural rainfall through your yard into storage areas via the use of various landscaping features borrow Mother Nature’s engineering. This is especially important during hot, dry summer months. If your yard is perfectly flat, you must move soil and features around to create more water-retaining contour areas.
First, complete a Percolation Test. This will provide critically important information about your landscape soil’s specific capacity to drain and to absorb water. Prep your soil as needed to turn it into a water-retaining sponge as much as possible before getting to work on rainwater capture plans.
NOTE: If you are working with existing hillsides, it’s best to get professional advice before grading or other significant changes. Before any digging, call Dig Alert 8-1-1 or digalert.org
Channels can be planted or lined with rocks and small boulders to resemble natural creek beds. Photo: Sweetwater Authority
Basins and swales are shallow depressions or channels no more than 12 to 24 inches deep, on gently sloped or nearly flat landscapes. Basins and swales move water over short distances. The plants in and around the depressions capture and sink small volumes of surface water.
Small, shallow depressions work best in clay soil areas, while sandy soils may accommodate the deeper depressions up to two feet. Channels can be planted or lined with rocks and small boulders to resemble natural creek beds.
Berms are mounds of raised soil, usually planted, that can border basins and swales or be used alone. Berms help contain and move water around, increasing the holding capacity of basins and swales
Boulders can add points of interest and slow down water runoff in your landscaping. Photo: San Diego County Water Authority
Boulders are useful to retain small berms or the edges of swales. They also create points of interest in your landscaping.
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.
Note the height and width of plant species when they mature when choosing plants for new sustainable landscapes. Proper plant placement, taking into account the mature plant’s size, will limit the need for regular pruning, and reduce the amount of maintenance required over time.
While regular pruning and removal of dead plant materials is vital in our region for wildfire prevention, overly aggressive pruning harms plant health and doesn’t allow natural shapes to emerge.
Note the height and width of plant species when they mature when choosing plants for new sustainable landscapes. Proper plant placement, taking into account the mature plant’s size, will limit the need for regular pruning, and reduce the amount of maintenance required over time.
While regular pruning and removal of dead plant materials is vital in our region for wildfire prevention, overly aggressive pruning harms plant health and doesn’t allow natural shapes to emerge.
Use the following spacing chart to help you figure out how many plants you need per square foot, based on the mature size of the plants.
Space plants on your landscaping plan at their full mature size, not the size when you first plant them. Graphic: San Diego County Water Authority
On your landscaping plan, use circles to note the size of every plant at maturity using a one-inch to four-foot scale. Use colored pencils to denote different water needs of the plants selected. It will make it easier to group plants into their proper irrigation zones (hydrozones).
Wide canopy trees that grow to 20 or 30 feet in diameter will significantly change the landscaping over time. Will this change the microclimates in the future? Consider whether a tree will cover a large section of landscaping with shade that is currently getting full sun. If plants that thrive in full sun are eventually covered in shade, the landscaping may need to be updated in time.
Planning for the amount of space your new plants will need when fully grown will help your landscape thrive. Photo: Sweetwater Authority
Select the smallest, healthiest plants possible, especially when choosing native plants. Once they are planted in properly prepared soil and watered wisely, small plants establish themselves more vigorously than plants raised in larger containers. Do not plant more than the space allows when the plants mature.
Take note of the root depth of plants when they are placed into the landscaping. Note the root depth on the plan. Trees will be irrigated less frequently, but for a longer period of time. Groundcovers with shallower roots require more frequent, shorter periods of irrigation. Keep these types of plants on separate hydrozones. Learn more about hydrozones
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.
Plants growing wild naturally arrange themselves into communities with other plant varieties based on their shared characteristics such as water and nutrient needs. This natural selection extends to interactions with each other, and with other species such as insects, birds, and other animals.
Plants growing wild naturally arrange themselves into communities with other plant varieties based on their shared characteristics such as water and nutrient needs. This natural selection extends to interactions with each other, and with other species such as insects, birds, and other animals.
As a result, we see the same plant communities occurring repeatedly in natural landscapes under similar conditions.
Local native plant communities evolve together over a long period of time. These plants work together to compete for nutrients, sunlight, and other resources. They flourish together, to the point of “rejecting” non-native plant varieties attempting to establish themselves. While non-native plants may be equally adapted as native plants to the climate conditions of a particular area, they are at a disadvantage.
By learning about the San Diego region’s native plant communities, and selecting plants that like to live together in communities for sustainable landscaping, homeowners can take advantage of these strengths and the resulting hardiness.
Perennial flowers outnumber the native grass species in California coastal prairies. Photo: Lloyd Waters / Pixabay
California’s coastal prairies are North America’s most diverse grasslands. Perennial flowers outnumber the native grass species. Plants include: California Poppy (Eschscholzia californica), Blue-eyed Grass (Sisyrinchium), Fern Leaf Yarrow (Achillea ‘Moonshine’), Seaside Daisy (Erigeron glaucus), and Cliff Buckwheat (Eriogonum parvifolium).
Fire-adapted, drought deciduous plants flourish in California coastal sage scrub. Photo: Couleur/Pixabay
Fire-adapted, drought-deciduous plants flourish in California coastal sage scrub. This habitat is rapidly disappearing due to urbanization in southern California. Fortunately, some areas, including the San Diego Safari Park Biodiversity Reserve, have been conserved. Plants include Grey Musk Sage (Salvia Pozo Blue), Sticky Monkeyflower (Diplacus aurantiaus), San Diego Sage (Salvia munzia), Fuschia Gooseberry (Ribes speciosum), and Woolly Bluecurls (Trichostema lanatum).
California chaparral is adapted to heat and dust. Photo: Kim R. Hunter / Pixabay
Chaparral exists in many coastal ranges and on the western and eastern slopes of the southern California mountains. It is ‘hard’ brush that doesn’t rely as much on summer fog drip that the Coastal Sage Scrub does, and it is adapted to heat and drought. Plants include Desert Mallow (Sphaeralcea ambigua), Bent Grass (Agorstis pailens), San Diego Mountain Mahogany (Cercocarpus minutiflorus), Bush Poppy (Dendromeconi riguda), and Clumping Wild Rye (Leymus condensatus).
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.
Hydrozones are the different areas of your landscaping where plants with similar irrigation needs are grouped together. This allows you to apply water as efficiently as possible through rainwater catchment, supplemented by irrigation, while avoiding unnecessary and wasteful overwatering.
Sun exposure, slopes, and plant root depths need to be taken into consideration along with plant water needs. All these characteristics create specific hydrozones. Even when the soil is the same, a full sun area is one hydrozone, full shade areas are another, and mixed exposure areas create yet a third. Shade from buildings or trees can also raise or lower temperatures.
Each irrigation valve should water its own separate hydrozone populated by plants with similar water needs, living conditions, and root depths. Plants with high water needs such as vegetables or lawns need to be grouped into their own hydrozone. Sprinklers or emitters on this zone shouldn’t overwater anything else.
Inspect your sprinkler heads regularly to make sure they are not obstructed or watering onto the pavement or other hardscapes. Photo: Irrigation Association
Each hydrozone must be able to handle enough water volume for every emitter to work properly. Hydrozones should have individual sprinklers or emitters delivering only the required amount of water, spaced out so every plant in the hydrozone receives an equal and accurate amount. If two sprinklers cross over one another, plants receiving water from both will receive more water than needed. In this example, sprinklers should be turned away from each other, or be reset farther apart. Professional landscapers call this “matched precipitation.”
This article is part of a year-long series inspired by the 71-page Sustainable Landscapes Program guidebook available at SustainableLandscapesSD.org. The Water Authority and its partners also offer other great resources for landscaping upgrades, including free WaterSmart classes at WaterSmartSD.org.
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.
The California Native Iris (Iris douglasiaria) is a plant that doesn’t mind having “wet feet,” or damp roots. Photo: Wikimedia Commons
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
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.
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.
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.
Look to the Microclimate Map for smart guidelines on choosing landscape plants. Consider this example yard with three identified microclimates:
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.
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.
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.
The Water News Network is San Diego County’s source for water news and information.
