July 9, 2022
By David Goldstein
It’s fairly clear by now that Americans living in arid regions have not adequately planned for water shortages.
In the current drought, local governments and water purveyors in the local region have responded with a new set of measures, including restrictions on outdoor watering.
In areas with the hottest climates and the most reliance on the Metropolitan Water District, restrictions include not just limiting outdoor watering to one day per week, but also limitations on the duration of this watering, the flow rate of sprinklers and a ban on runoff.
In these areas, the amount of water possible for application to lawns is far less than the amount recommended in a U.C. Davis Lawn Watering Guide for California, sent to me recently by John Fonti of Newbury Park. Consequently, one local drought response measure will likely be widespread browning or replacement of lawns.
Indeed, according to Dr. Jim Downer, a UC Cooperative Extension farm advisor who specializes in turf grass and is based at the university’s Ventura office, some lawns in some parts of Ventura County will not just go dormant—some lawns will die.
Downer, like most dedicated scientists, provided several caveats. As detailed in his Gardenprofessor.com blog, the wide range of turf grass varieties and species will respond differently to water deprivation.
Warm-season grasses, including Bermuda grass, St. Augustine grass, and kikuyu can survive conditions deadly to cool-season grasses, such as Kentucky bluegrass, rye grass, and tall fescue.
Unfortunately, tall fescue is the variety used in Marathon Sod, which is common in Ventura County.
“If we get the expected hot weather, in areas with tough watering restrictions, this grass will die and it won’t come back,” said Downer.
“In contrast,” he continued, “Kikuyu grass can survive months with no applied water, especially on the coast, but even in hotter parts of Ventura County.”
Similarly, buffalograss can survive “by being brown nine months of the year,” and bermudagrass “can come back after dying in dry ground, all the way to back to the stolon,” said Downer, referring to an underground stem capable of regenerating a lawn after rain returns or watering restrictions ease.
Rather than maintain year-round, lush expanses of green, Downer suggests people limit lawn size and think of lawns as a seasonal garden.
His own garden in Ojai previously had 1,000 square feet of grass. He reduced it to 100 square feet of St. Augustinegrass, shaded by trees and watered only when the trees are watered.
The rest of his yard is now a seasonal meadow. Wildflowers bloom in the spring, die, and set seed for the next year.
Additional variables for grass survival include shade, slope, and soil type. Loam is the best soil. Clay soil holds the most water but does not make it as available to plants.
If you have sandy soil, especially if you previously watered too frequently for your grass to develop deep roots, then you have another reason to consider turf replacement, rather than hope for grass survival.
To find turf replacement incentives in your area, go to the website of the purveyor to whom you pay your water bill.
As a baseline enhanced by some local purveyors, incentives through the Metropolitan Water District include $2 per square foot rebates for replacing turf with a specified list of options.
The options must include three plants per 100 square feet, a stormwater retention feature, and replacement or modification of spray sprinklers. No hardscape is allowed, other than permeable materials, and synthetic turf is not allowed.
This prohibition on incentives for synthetic turf is replicated by other local water purveyors in Ventura County, in part because some people use water to cool or clean the plastic.
Taking issue with this prohibition, Jack Sheehan called me recently and reported, “Fake grass has always been a great way to save water and still have a lawn.”
When reworking your garden, using mulch and compost are important measures for soil health and water retention. Locally, Agromin and Peach Hill are the main sellers of both.
Their decorative walk-on bark is a by-product of fir trees used in paper mills, and both also have attractive mulch ground cover, which can go over a dead or dying lawn, made from recycled wood and brush collected from local trimmings.
David Goldstein is an environmental resource analyst with the Ventura County Public Works Agency. Reach him at (805) 658-4312 or firstname.lastname@example.org.