‘Be prepared for some brown’: Spokane horticulturists offer yard advice during drought
For many Americans, a lush lawn of green grass is the essence of summer.
It’s a status symbol for the proud homeowner. An inviting Wiffle ball field. A beacon for barbecues.
In arid Spokane, however, keeping a lawn green can be hard work. Rain alone usually can’t do the job, which means yards in the Inland Northwest typically need watering.
With the city’s new water restrictions, keeping plants alive will be more difficult.
Spokane last week instituted more stringent drought response measures after flows in the Spokane River fell below 1,000 cubic feet per second. Residents aren’t supposed to water their lawns more than twice a week, for two hours a day. The Spokane City Council approved the policy last year, although this is the first time low river levels have triggered it.
The Level 2 restrictions are an add-on to the city’s Level 1 rules, which go into effect from June 1 to Oct. 1 every year and limit water use to four times a week from 6 p.m. to 10 a.m.
The ordinance includes an exemption for watering trees and vegetable gardens, and allows for watering that mitigates fire risks.
Spokane’s water cutbacks won’t doom all yards, but they will force people to prioritize certain plants over others, according to Tim Kohlhauff, a master gardener coordinator with the Washington State University Extension in Spokane County.
“People should be prepared for some brown in their landscape,” Kohlhauff said. “Budget the water you have so it goes to the plants that are important to you.”
Different lawns need different amounts of water. It all depends on the species of grass, the amount of shade, the type of soil and how healthy the roots were before the heat of summer arrived.
In general, Eastern Washington lawns need about an inch of water a week, Kohlhauff said. They get thirstier when it’s hotter, however.
Cindy Deffé, a horticulture instructor at Spokane Community College, said it’s good to water an extra half-inch for every 10 degrees above 60 degrees.
A lawn could need 2½ inches of water a week to stay green in 90-degree heat, she said. Setting empty tuna cans under the sprinkler’s coverage area, and measuring the water the cans catch, is an easy way to track how much water a sprinkler delivers.
People frequently overwater their lawns. Deffé said watering every day is a mistake.
Grasses that get constant water in spring don’t develop deep roots, and without deep roots they have a hard time weathering droughts.
“We never need to water daily for anything, unless it’s a brand-new planting and we’re trying to get seeds to germinate,” she said. “Water as necessary in the spring – so it might be every couple weeks, depending on how much rain we’re getting.”
Deffé recommends watering early in the morning, ideally before sunrise, to avoid excessive evaporation. It’s best to avoid watering when the washing machine’s running or someone’s in the shower, too, because that can reduce water flow.
Yard lovers needn’t despair when they see brown blades of grass. Grasses can go dormant when they’re stressed, Kohlhauff said, to conserve energy. Plants that go dormant in summer can often re-emerge healthy next spring.
While turf does best with smaller doses of water, trees tend to fare better with a good soaking once or twice a week.
Deffé said people should check the soil around the tree, an inch or two below the surface, to see if it’s dry. If it is, the tree could use some water.
Kohlhauff said native trees, such as ponderosa pine, are well-adapted to drought and generally need less care to make it through summer. Birches, Japanese maples and other trees that wouldn’t naturally grow in Spokane’s front yards need more attention.
Both plant experts said people should expect more dry summers in the future. Paring back the amount of turf in yards, when possible, is wise.
“Reducing that amount of turf so that the whole open area is not turf grass is certainly recommended,” Deffé said. “But having an area for kids to play is still good as well.”