By Kathy Hansen, WSU Extension, Master Gardener, Stevens County
The National Weather Service’s Climate Prediction Center recently released its three-month outlook for July, August and September, which calls for above-average temperatures and below-average precipitation for the Pacific Northwest. “The seasonal drought outlook is calling for the drought to persist for central and eastern WA,” the report stated. Last August’s gardening column discussed garden watering, but after a strikingly dry 2021 spring, we take a deeper dive into waterwise gardening to confront heat and drought conditions.
Some waterwise strategies need to be implemented at the beginning of the season. Thus, consider for next year selecting drought-resistant plants (see Oregon State University Extension Service’s list at https://extension.oregonstate.edu/gardening/techniques/incorporating-pacific-northwest-native-plants-your-water-wise-landscapes), encouraging a deep root system to collect water by prepping the soil, and, as Rod Smith suggests, “grouping plants according to water needs.” Since grassy lawns are the biggest water hogs, consider replacing all or part of your lawn with drought-resistant or low-water-use plants. In the meantime, a mowing height of 2.5-3.5 inches will help cool the soil and cut down on the lawn’s need for water.
The goal of waterwise gardening, Smith writes, “is to conserve water by using it efficiently.” Oregon State University Extension notes that across the nation, irrigating landscapes uses about a third of the water supply. Here are tips for efficient water use that you can implement even if you’ve implemented none of the early-season strategies:
Help plants establish root systems: A well-established root system is one of the keys to waterwise gardening. Thus, when watering, prioritize new plants you’ve introduced this year.
Add compost to soil: Organic matter helps plants retain water. Swanson’s nursery recommends amending soil with 4-6 inches of compost.
Water early in the day: No matter how hot it gets here in Stevens County, we can usually count on cool mornings. Water between sunrise and 10 a.m. to reduce evaporation. Smith recommends spreading tuna cans around the watering area to gauge whether water is being evenly distributed.
Consider drip irrigation or soaker hoses. WSU Extension’s publication, “Drip Irrigation for the Yard and Garden,“ notes that sprinklers are only 70 percent efficient in delivering water to plants, while drip irrigation is up to 95 percent efficient. (Check out this publication at https://pubs.extension.wsu.edu/drip-irrigation-for-the-yard-and-garden for how to set up a system)
Retain moisture with 2-3 inches of mulch. In addition to holding moisture, mulch provides protection for ornamentals and garden plants susceptible to heat damage. Wood chips and fallen deciduous leaves are excellent mulching materials. If using a soaker hose or drip-line, consider covering the hose with mulch to help prevent evaporation.
Water deeply but less often. Deep watering a couple of times a week is more efficient than shorter, more frequent waterings. Avoid overwatering, which not only wastes resources but can remove oxygen from the soil and suffocate roots.
WSU Extension Service Publication EB1090: Watering Home Gardens and Landscape Plants: https://pubs.extension.wsu.edu/watering-home-gardens-and-landscape-plants
WSU Extension Service Publication EM087E: Drought Tolerant Landscaping for Washington State: https://pubs.extension.wsu.edu/drought-tolerant-landscaping-for-washington-state-home-garden-series
The WSU Extension Master Gardener Program trains volunteers to be effective community educators in gardening and environmental stewardship. Master Gardeners provide information generated from research at WSU and other university systems. Kathy Hansen is an educator, writer, social-media junkie, career practitioner, and 5-star short-term rental superhost at Hansen Woodland Farm (http://www.hansenwoodlandfarm.com/) in Kettle Falls.