Using Groundcovers To Create Waterwise Landscapes in Coastal California
by David Salman
Inspiration For Replacing Lawns in the Intermountain West
California, which has been suffering the effects of prolonged drought for the past 4 to 5 years, has a huge palette of non-cold hardy waterwise plants that they use to create xeric landscapes. Those of us in the rest of the western US should look at their landscapes as inspiration and borrow their designs and design elements using plants suitable for colder regions, such as the Intermountain West.
Say No to Gravel and Yes to Groundcovers
Front and side yard lawns are the most obvious component of many yards that can be replaced when converting a conventional landscape to a xeric (waterwise) one. These lawns are used simply as green groundcovers because their value as foot traffic tolerant turf goes unused. So why not use low care, low water groundcovers instead? The amount of work and expense that goes into mowing, fertilizing and watering a lawn will be greatly reduced. And groundcovers provide beautiful flowers that grass doesn't.
Most commonly, homeowners will chose gravel to replace the lawn. But gravel is:
Ugly and creates uncomfortable visual glare.
Has no value as habitat for pollinators and songbirds.
Increases the need for home air conditioning as the gravel absorbs heat and the cooling effects of the lawn is gone.
Often results in the loss of valuable shade trees when the irrigation water once used on the lawn has stopped.
Extensive use of gravel and other hardscapes that absorb heat, contribute to the bigger problem of urban environmental heating (the "urban heat island" effect).
However, areas of gravel mulch are an excellent environment into which heat tolerant groundcovers can be planted. And we have a plethora of cold hardy groundcovers from which to choose as you'll see below.
Techniques for Replanting Groundcovers
When replanting into gravel or replacing the sod directly with groundcovers, leave the old sprinkler system in place. Sprinklers are the best way to irrigate big areas planted with groundcovers. This saves the expense and effort of putting in a new drip system. And you'll be using the sprinklers much less often once the groundcovers are established.
Use a variety of groundcovers species to improve the habitat value and visual beauty of your landscape. Or plant only one type of groundcover if the uniform look of your old lawn is desirable, and you want to duplicate it in a much more water efficient way. With either choice, most groundcovers can be planted on 15-18" by 15-18" centers and will generally fill in by the end of the first growing season.
When planting multiple species or varieties, group them in "drifts" (large patches of the same plant) to maximize visual interest.
It is a nice design element to plant islands of taller growing ornamental grasses and flowering perennials into the groundcovers to give your ex-lawn a less flat, and more visually interesting look to your front yard. Create patches of natural nectar to attract hummingbirds or fruit bearing shrubs to attract songbirds.
Place some stepping stones or flagstone pieces to create walkways across the groundcovers. But first, observe where you've been walking previously so to minimize the wear and tear on your new groundcovers.
Soil preparation is important, especially when replacing old lawns where the soil has been worn out and compacted. Dig individual holes for each plant and enrich the soil with Yum Yum Mix and compost. Or spread compost and Yum Yum Mix over the whole area and rototill it in to facilitate the groundcovers to root more readily as they grow out across the soil.
Use corn gluten as a natural pre-emergent herbicide to reduce weeds while the groundcovers are filling in.
Cotula (Creeping Gold Buttons)- an outstanding evergreen groundcover with attractive flowers. Good tolerance to foot traffic. Deep roots and attractive ferny foliage.
Delosperma (Cold Hardy Ice Plants) - There are so many great choices. My favorites include Red Mountain Flame. 'Blut', 'Lavender Ice' and D. nubiginum (great for partial shade). You must use stepping stones to walk through big patches of Ice Plant, as they crush underfoot.
Hardy Plumbago (Ceratostigma plumbaginoides) is one of the most versatile groundcovers for cold climates growing in both sun and shade and most soil types. Plumbago blooms in late summer with deep blue flowers followed by the foliage that turns burgundy red in fall.
1" tall x 18" wide. Pink Chintz Thyme (Thymus Pink Chintz) is a tight, low growing creeping thyme with thick stems of woolly green foliage that blooms in mid-spring with a profusion of salmon-pink flowers.
Pink Creeping Thyme is an outstanding selection with glossy, dark green leaves covered with light pink flowers pushing form rose-pink buds in early summer. This variety is impressively xeric, with tough woody stems. Drought resistant/drought tolerant plant (xeric).
Veronica pectinata (Woolly Speedwell) is one of our finest groundcovers. Growing with long stems of wooly evergreen foliage, the plants cover themselves with blue blooms, aging to lavender-blue flowers in early to mid-spring. 2" tall x 18" wide.