Conserving water outdoors with native species and design
During the heat of the summer in the Treasure Valley, water provider Veolia says as many as 95 million gallons of water each day flow through taps serving their roughly 260,000 customers. That’s three times as much during most winter days, and they aren’t the only water provider in the area. Much of that summer excess goes to irrigate lawns and gardens.
Some residential properties can water their landscapes off the miles of irrigation canals and ditches fed by the Boise River. None of that existed 150 years ago.
“Without those irrigation canals, we would not have the agriculture that we have here,” said Daniel Murphy, plant collections curator at the Idaho Botanical Garden.
As residential development has gobbled up farmland in Idaho and the American west, more of all that water is used on ornamental cool-season grass lawns - thirsty non-native species like Kentucky Bluegrass.
“We live in a sagebrush steppe, which means your sagebrushes and your bunchgrasses and things that you see out in the foothills,” Murphy explained of the type of plants the area’s modern-day settlers would have found.
Murphy and Botanical Garden Horticulture Director Duran Villegas showed off the "dry garden," an example of plants more native to our high desert environment, and less thirsty too.
“Plants that are very drought tolerant that we would hope could be able to handle not being irrigated at all during the summer time,” Daniel said.
Known as xeriscaping, the word comes from the Greek ‘xeric,’ which means ‘dry,’ or ‘arid.’ Villegas said people don’t always appreciate the look - and often mistake xeriscaping with ‘zeroscaping,’ an absence of plants in a landscape.
“They don't think that it's very pretty,” he said. “They say, oh, that looks like cactus, or that looks like a bunch of dry twigs, but because they don't see it in the proper setting and they don't see it when it's blooming, it's hard to appreciate xeriscape plant material landscape for what it is.”
At the Idaho Botanical Garden, the dry garden includes plants native to sagebrush steppe: penstemons (beardtongue).
“They've got little tubular colored shaped flowers,” Murphy explained as we walked through.
There’s primroses, evening buckwheat, globemallow and members of the aloe and yucca family, too.
“We have our hummingbird trumpet - it's native to eastern Idaho and incredibly drought tolerant,” Murphy continued. “It's more of a low-growing ground cover type of plant, but it flowers all summer long.”
While a rock mixture including red volcanic rock, pea gravel and decomposed granite is used as ground cover between plants in the dry garden, that’s not the only option. In fact, it’s not easy to give blanket advice because soil composition, sun, shade, slope and drainage can vary so much from one property to another.
“You'll get the most out of your garden just by the way you situate the garden,” Villegas said. “The flowers, when they come into season, they're quite beautiful.”
Villegas said the Garden gets regular visitors interested in adding more native plants to their home gardens. Developers are starting to have more conversations about native landscape design, too.
Chad Lorentzen is a landscape designer at The Land Group in Eagle.
“It's being responsible with our resources, the limited resources that we have,” he said. The data he uses show about a one-third reduction in water usage by using more native resources.
“If the only time that you step foot on your lawn is to mow it, it's the wrong plant,” he quipped.
Lorentzen and other professionals shared that sentiment. They all echoed similar versions of the same concept: having the right plant in the right place is, by default, almost always more water efficient.
Lorentzen points to a new development in west Meridian called Owyhee Springs, which has an eight-acre communal space.
“Within that, essentially 50% of that open space is a meadow approach,” he explained. “So it's incredibly resource resilient and does not demand a great deal of supplemental irrigation throughout the year.
Lower maintenance costs appeals to developers, even if they have to wait years for some types of native landscapes to fully mature - in the case of Owyhee Springs, about three years.
Lorentzen says The Land Group drew inspiration from a Utah community that installed a native meadow landscape years ago. The example helped sell the concept here. Local governments are also recognizing the need for updated policy to help guide development decisions.
In September, the city of Nampa strengthened its requirements for water-wise vegetation in public spaces and new developments. It also tightened limits on how much decorative lawn developers can install.
Those recommendations, passed unanimously and without discussion by the council as part of a broader update to city code Sept. 5, were brought to council by the city’s drought task force.
Nampa Spokeswoman Amy Bowman said the memory of drought conditions several summers ago remains fresh in the community and they want to ensure that the resource is protected and available for continued use in the important local agriculture economy. They developed a landscape guide as a resource for residents to use.
The City of Boise’s code prohibits the use of decorative, high-water grass varieties from being used in non-active areas, like roadway medians, and limits the use of those same grasses to just 33% of turfed space within a new development, unless they’re used for recreation spaces.
So what do you do if you’re considering making a change but you also still want to have some turf grasses because you have kids and pets?
“There's a lot of movement and talk about eliminating lawns from landscape in today's world because of water use. And I feel that that's a mistake,” said Brett Van Paepeghem. He’s the southern Idaho project manager for Idaho Firewise.
If you’ve seen their xeric, specifically fire resistant garden next to the Idaho Botanical Garden, you’ve seen his work - including a row of a dozen turf squares no bigger than 50 square feet each, with the thirstiest grasses at one end and low-water grasses at the other. Van Paepeghem says the project hopes to educate people that, “there's more than one kind of grass out there; that we can have grass and not use so much water.”
Common lawns use cool-season grasses, which are, “naturally actively growing and green, and in their natural state would be going dormant during the warm season of July and August,” Van Paepeghem explained.
He doesn’t have a favorite plant (the question he’s most often asked) but does like the sheep fescue, a more natural cool-season turf that can be cut and managed just like a kentucky bluegrass lawn but with less water.
The warm-season grasses, like ‘dog-tuff,’ a proprietary blend, and blue grama, need about half the water compared to bluegrass, but they go dormant quickly each fall. Their growth season is during the hottest time of the year, but when I visited, they were already straw-yellow. That’s a turn-off for some homeowners and homeowners associations, groups that can control or restrict the appearance of someone’s property.
Some HOAs require decorative lawns and penalize homeowners who don’t keep them trimmed and green. State Sen. Rick Just (D-Boise) is ready to propose a new bill that would change at least part of that.
“What my legislation would do would prohibit HOAs from requiring lawns,” he said. “If you want a lawn, you can still have one, but you don't have to have one anymore.”
Just xeriscaped his property four years ago and said he’d never go back to grass. He’s heard from a few folks in the community concerned about not being able to alter their yards the same way because of HOA restrictions, or the common misconception that it’s only rock and cacti.
Just thinks he could find widespread support for his bill by pitching it as a protection of private property rights.
In the meantime, the advice to homeowners in an HOA is to communicate your plans and maybe even join your HOA board to push for change. Some of the pushback could be solved by educating neighbors on what xeric landscaping is. Starting small is another option.
“The term that we use often is ‘editing’ a landscape,” said The Land Group’s Lorentzen. “Going in and finding if there are some simple switches for plant material for example, or switching a turf area that's underutilized and moving it into a pollinator friendly space.”
He said no matter how you start, re-thinking the irrigation system is also important - and often overlooked. The Botanical Garden’s Murphy thinks many homeowners can likely reduce their water use just by fine-tuning what they have.
“Some people over-water already,” he said. “So even just cutting back a little, their plants are going to be fine. So it's really just watching the plant and seeing how it's responding to the climate and to the conditions.”
Xeric landscape installation is still in its early adoption stage here, because there’s been no widespread drought or catastrophe to spur more people into making a change.
“Isn't that always the truth, that we don't change our behavior until something mandates us to change our behavior. And so a drought could pretty well do that, as well as hitting your pocketbook” said the Botanical Garden’s Villegas.
He should know, having recently relocated to Idaho from California, where government-issued water use restrictions are becoming more and more common. But, he said, it took 6-7 years of drought conditions - and the associated cost increases - for people there to really start to change their consumption habits.
“There will be times where we have lots of water, lots of snow, lots of precipitation, and other times where that won't be the case. And so how do you best manage that resource? Some people believe you just live within your means. Others believe that it's an unending resource; we should be able to use it as we feel fit. And of course, there are consequences to that when the resource kind of starts to go away or is limited.”