{"id":1661,"date":"2025-11-12T09:54:09","date_gmt":"2025-11-12T17:54:09","guid":{"rendered":"https:\/\/extension.wsu.edu\/pnw-gardeners-handbook\/?page_id=1661"},"modified":"2026-04-14T11:43:03","modified_gmt":"2026-04-14T18:43:03","slug":"chapter-25-waterwise-landscaping","status":"publish","type":"page","link":"https:\/\/extension.wsu.edu\/pnw-gardeners-handbook\/chapter-25-waterwise-landscaping\/","title":{"rendered":"Chapter 25: Waterwise Landscaping"},"content":{"rendered":"<div class=\"wsu-hero wsu-width--full wsu-pattern--wsu-light-radial-left  wsu-hero--style-boxed \">\n\t<div class=\"wsu-hero__background\">\n\t\t<div class=\"wsu-image-frame wsu-image-frame--fill\">\n\t<img decoding=\"async\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/09\/Depositphotos_32793155.jpg\"\n\t\tsrcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/09\/Depositphotos_32793155.jpg 1350w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/09\/Depositphotos_32793155.jpg 300w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/09\/Depositphotos_32793155.jpg 1024w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/09\/Depositphotos_32793155.jpg 768w\"\n\t\tsizes=\"(max-width: 1350px) 100vw, 1350px\"\n\t\talt=\"Close-up of a drip irrigation emitter attached to a black hose, releasing multiple small streams of water.\"\n\t\tstyle=\"object-position: 75% 32%\"\n\t\t\/>\n<\/div>\n\t<\/div>\n\t<div class=\"wsu-hero__overlay\">\n\t<\/div>\n\t<div class=\"wsu-hero__content-wrapper\">\n\t\t<div class=\"wsu-hero__inner-content-wrapper\">\n\t\t\t\t\t\t<div class=\"wsu-hero__title-wrapper\">\n\t\t\t\t<h1 class=\"wsu-hero__title\">Waterwise<br>Landscaping<\/h1>\t\t\t\t<div class=\"wsu-hero__caption\">Chapter 25<\/div>\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<div class=\"wsu-hero__content\">\n\t\t\t<\/div>\n\t\t<\/div>\n\t<\/div>\n<\/div>\n\n\n\n<p class=\"wsu-max-width--hero wsu-spacing-after--xsmall\"><strong>Bob Simmons<\/strong>, Associate Professor of Water Resources, Washington State University<\/p>\n\n\n\n<p class=\"wsu-max-width--hero wsu-spacing-after--xsmall\"><strong>Teresa C. Koenig<\/strong>, Adjunct Faculty Member, Department of Horticulture, Washington State University<\/p>\n\n\n\n<p class=\"wsu-max-width--hero wsu-spacing-after--xsmall\"><strong>Richard Koenig<\/strong>, Professor, Department of Crop and Soil Sciences, Washington State University<\/p>\n\n\n\n<p class=\"wsu-max-width--hero wsu-spacing-after--xsmall\"><em>Excerpted and adapted with permission from material published by the authors while they were members of the faculty at Utah State University.<\/em><\/p>\n\n\n\n<div style=\"height:10px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\" \/>\n\n\n<div class=\"wsu-row wsu-row--sidebar-right\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<h2 class=\"wp-block-heading wsu-font-size--xlarge wsu-heading--style-marked wsu-spacing-after--xxmedium\" id=\"learning-objectives\">Learning Objectives<\/h2>\n\n\n\n<ul>\n<li>Understand how to plan your landscape to be efficient in water use.<\/li>\n\n\n\n<li>Understand the concepts behind soil preparation and plant selection for waterwise landscaping.<\/li>\n\n\n\n<li>Know basic principles for waterwise landscape management and irrigation.<\/li>\n<\/ul>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<h2 class=\"wp-block-heading\">Topics Covered<\/h2>\n\n\n\n<ul class=\"wsu-menu--style-sidebar\">\n<li><a href=\"#ch25-introduction\" data-type=\"internal\" data-id=\"#ch25-introduction\">Introduction<\/a><\/li>\n\n\n\n<li><a href=\"#ch25-planning-and-design\" data-type=\"internal\" data-id=\"#ch25-planning-and-design\">Planning and Design<\/a><\/li>\n\n\n\n<li><a href=\"#ch25-soil-preparation\" data-type=\"internal\" data-id=\"#ch25-soil-preparation\">Soil Preparation and Management<\/a><\/li>\n\n\n\n<li><a href=\"#ch25-plant-selection\" data-type=\"internal\" data-id=\"#ch25-plant-selection\">Plant Selection<\/a><\/li>\n\n\n\n<li><a href=\"#ch25-turfgrass-placement\" data-type=\"internal\" data-id=\"#ch25-turfgrass-placement\">Turfgrass Placement in the Landscape<\/a><\/li>\n\n\n\n<li><a href=\"#ch25-mulching\" data-type=\"internal\" data-id=\"#ch25-mulching\">Mulching<\/a><\/li>\n\n\n\n<li><a href=\"#ch25-irrigation-planning\" data-type=\"internal\" data-id=\"#ch25-irrigation-planning\">Irrigation Planning and Practices<\/a><\/li>\n\n\n\n<li><a href=\"#ch25-landscape-maintenance\" data-type=\"internal\" data-id=\"#ch25-landscape-maintenance\">Landscape Maintenance<\/a><\/li>\n\n\n\n<li><a href=\"#ch25-further-reading\" data-type=\"internal\" data-id=\"#ch25-further-reading\">Further Reading<\/a><\/li>\n<\/ul>\n\n<\/div>\r\n\n<\/div>\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\" \/>\n\n\n\n<h2 class=\"wp-block-heading  wsu-heading--style-marked\" id=\"ch25-introduction\">Introduction<\/h2>\n\n\n\n<p>Besides being economical, a waterwise landscape can also be functional, attractive, easily maintained, and can have a cooling effect on its surroundings. Applying the principles of waterwise landscaping can conserve precious water resources, protect our groundwater aquifers, and prevent chemical pollution inputs from harming our groundwater and local waterways. The term \u201cxeriscaping,\u201d from the Greek word <em>xeros<\/em>, meaning dry, is generally synonymous with waterwise landscaping.<\/p>\n\n\n\n<p>In Washington, during the late spring and summer months, a vast amount of municipal water is used for irrigating landscapes. Much of that water is wasted, because more is applied than plants need due to inefficiencies in the irrigation system and methods of application. Overspray, due to poor irrigation system planning, operation, and maintenance, also causes substantial damage to hardscape materials, such as walls, decks, patios, fences, and decorative stone. Excess water use can be reduced by using more efficient irrigation systems and scheduling irrigation according to the needs of the landscape. Besides conserving water, proper irrigation benefits the garden and landscape by encouraging deeper root growth and healthier, more drought-tolerant plants.<\/p>\n\n\n\n<p class=\"wsu-spacing-after--xsmall\">It should be noted that the climate varies considerably across the state; however, there are key principles that are universal. Water can be conserved in a landscape by incorporating one or more of Knopf\u2019s principles, outlined in his 1999 book, <em>Waterwise Landscaping with Trees, Shrubs, and Vines: A Xeriscape Guide for the Rocky Mountain Region, California, and the Desert Southwest<\/em>. His principles include:<\/p>\n\n\n\n<ol class=\" wsu-list--columns-1\">\n<li>Planning and design<\/li>\n\n\n\n<li>Soil preparation and management<\/li>\n\n\n\n<li>Plant selection<\/li>\n\n\n\n<li>Practical turfgrass areas<\/li>\n\n\n\n<li>Mulching<\/li>\n\n\n\n<li>Irrigation planning and practices<\/li>\n\n\n\n<li>Landscape maintenance<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading  wsu-heading--style-marked\" id=\"ch25-planning-and-design\">Planning and Design<\/h2>\n\n\n\n<p>A landscape plan should meet the needs of the people who will use and maintain the area while incorporating the site\u2019s existing environmental assets and constraints into the design. The planning and design stage of landscaping provides the opportunity to consider and prepare for all aspects of the area\u2019s future use. Climate change impacts should also be considered, and incorporate planning for warmer temperatures, greater chance of drought, less irrigation water availability, and heavier rainfall events. Designing the landscape to use water efficiently is a primary objective. This can be accomplished by selecting low-water-use plants, designing and scheduling irrigation systems efficiently, grouping plants according to their water requirements, and using hardscaping materials (patios, stone paths, decks, etc.) appropriately to reduce the area requiring irrigation.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><em>Conduct a Site Analysis<\/em><\/h3>\n\n\n\n<p>Inspect the site and identify the environmental assets and constraints that will influence the design. Take notes on factors such as seasonal effects of sun and shade, soil conditions, slopes, direction of winds, and views from various locations on the site. These will be important in developing the design.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"alignright size-full is-resized\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/10\/Fig_01-14.jpg\" alt=\"Simple plot plan illustration showing a house, driveway, downspouts, utilities, slopes, garden beds, and surrounding vegetation including evergreens and small deciduous trees and shrubs.\" class=\"wp-image-3815\" width=\"591\" height=\"385\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/10\/Fig_01-14.jpg 788w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/10\/Fig_01-14-300x195.jpg 300w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/10\/Fig_01-14-768x500.jpg 768w\" sizes=\"(max-width: 591px) 100vw, 591px\" \/><figcaption class=\"wp-element-caption\">Figure 1. Example of a simple plot plan. Illustration: Noelle Hart.<\/figcaption><\/figure><\/div>\n\n\n<h3 class=\"wp-block-heading\"><em>Develop a Plot Plan<\/em><\/h3>\n\n\n\n<p>Develop a plot plan of the area to be landscaped. This is simply a map of the site with the location of existing structures, trees and shrubs, property lines, driveways, gardens, utility lines, contours of the land, and other possible limitations to the design. Use graph paper to prepare a scale map of the property, letting each square on the paper represent a defined area in the landscape. Figure 1 provides an example, and at the following websites you can find a <a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2056\/2022\/11\/Media-Release-Rural-Stormwater-11.3.22.pdf\" data-type=\"URL\" data-id=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2056\/2022\/11\/Media-Release-Rural-Stormwater-11.3.22.pdf\" target=\"_blank\" rel=\"noreferrer noopener\">Rural Stormwater Solutions fact sheet (links to PDF document)<\/a> and <a rel=\"noreferrer noopener\" href=\"https:\/\/ruralstormwater.wsu.edu\/videos\/\" data-type=\"URL\" data-id=\"https:\/\/ruralstormwater.wsu.edu\/videos\/\" target=\"_blank\">video (opens in new window)<\/a>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><em>Plan the Design<\/em><\/h3>\n\n\n\n<p>Based on the environmental assets and constraints identified in the site analysis, decide where plants should be placed for optimum aesthetic value, screening of undesirable views, shade or windbreaks, and separation of areas of the landscape. Consider the use of hardscaping materials such as patios, paths, and decks. When using hardscape elements, seek permeable options wherever possible. These include permeable pavers, \u201cgreen joints\u201d between pavers or urbanite, and permeable concrete, to name a few options. A goal of waterwise landscaping is to slow stormwater runoff to allow recharge of groundwater aquifers. Using these hardscaping elements can also enhance the landscape design while reducing the amount of area that needs to be irrigated and maintained.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><em>Minimize Energy Consumption<\/em><\/h3>\n\n\n\n<p>Deciduous trees should be placed on the south, east, and west sides of a building to take advantage of the potential benefits of winter sun and summer shade to heat or cool a building. Evergreens are good insulators but limit sunlight, so try to plant them on the north side of a building. To protect a home from cold and snow, use trees and shrubs as insulators or windbreaks along the structure. Structural and safety issues should be taken into account when placing trees and shrubs near structures.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><em>Plant According to Water Zones<\/em><\/h3>\n\n\n\n<p>Installing drought-tolerant plants that require little or no supplemental water is a big part of waterwise landscaping. Plants adapted to dry, arid regions should survive with little or no water. However, during establishment, most plants will need supplemental irrigation. Establish zones according to the amount of water you would like to use or can afford for the landscape, and what you wish to achieve aesthetically and environmentally.<\/p>\n\n\n\n<p>Plants that require more water do not have to be excluded from a waterwise landscape. However, they do need to be grouped together in locations (i.e., zones) that suit their needs, recognizing that more water and attention will be required to maintain them.<\/p>\n\n\n\n<p>When choosing plants, identity their water requirements and group those with similar requirements in the same area or irrigation zone. For example, zones can be separated into zero (no irrigation), one (irrigate once each month), two (irrigate twice each month), three (irrigate weekly), and four (irrigate twice each week).<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><em>Selecting Plants<\/em><\/h3>\n\n\n\n<p class=\"wsu-spacing-after--small\">Select plants that will most effectively achieve the design and use goals of the landscape, and remember the good advice, \u201cRight plant, right place.\u201d Consider using native and noninvasive plants and approved waterwise non-native species and cultivars to fill in where native plants do not provide for the needs of a particular site and its goals. Use species that are adapted to the soil, water, temperature, light, and pest conditions of the landscape environment to help minimize maintenance and water requirements. When choosing plants to include in the landscape design, consider:<\/p>\n\n\n\n<ul>\n<li>Aesthetics\u2014Size, shape, color, and form that will best accomplish the design goals.<\/li>\n\n\n\n<li>Function\u2014Plant to conserve energy or water, block undesirable views or noise, provide food for people or wildlife, and control erosion on steep slopes.<\/li>\n\n\n\n<li>Soils\u2014Most plants do well under a range of soil conditions; however, many plants have an optimum pH range, salt tolerance level, soil texture, soil drainage, and soil moisture requirement (see Chapter 3: Soil Science for more information). Check labels for more information on specific plant requirements and adaptations.<\/li>\n\n\n\n<li>Water\u2014Select low-water-use plants or plants adapted to the water situation in the region. Incorporate smaller plants into the design; they will use less water at maturity than large species.<\/li>\n\n\n\n<li>Climate adaptation\u2014Choose plants adapted to the USDA\u2019s local hardiness zones, which are based on the minimum, annual survival temperatures for plants. Washington has a range of hardiness zones throughout the state. Contact your local Washington State University Extension office to learn more about the hardiness zone for your area, or go to the <a href=\"https:\/\/planthardiness.ars.usda.gov\/PHZMWeb\/\" data-type=\"URL\" data-id=\"https:\/\/planthardiness.ars.usda.gov\/PHZMWeb\/\" target=\"_blank\" rel=\"noreferrer noopener\">USDA Plant Hardiness Zone Map (opens in new window)<\/a>. See Chapter 11: Herbaceous Landscape Plants for a discussion of hardiness zones and choosing suitable landscape plants. Note that microenvironments, created by a plant\u2019s immediate surroundings, and microclimates can also influence its hardiness in a region.<\/li>\n<\/ul>\n\n\n\n<p>For more detailed information on planning and designing a waterwise landscape, see <a href=\"https:\/\/pubs.extension.wsu.edu\/drought-tolerant-landscaping-for-washington-state-home-garden-series\" data-type=\"URL\" data-id=\"https:\/\/pubs.extension.wsu.edu\/drought-tolerant-landscaping-for-washington-state-home-garden-series\" target=\"_blank\" rel=\"noreferrer noopener\">Drought Tolerant Landscaping for Washington State (opens in new window)<\/a> and consult other references listed in the Further Reading section at the end of this chapter.<\/p>\n\n\n\n<h2 class=\"wp-block-heading  wsu-heading--style-marked\" id=\"ch25-soil-preparation\">Soil Preparation and Management<\/h2>\n\n\n\n<p>Soil is the most important component of the landscape. Many well-designed landscapes have failed because of inadequate soil preparation before planting or soil management after planting. Proper soil preparation and management also improves landscape water conservation by increasing plant rooting depth and soil\u2019s water-holding capacity and reducing water runoff and evaporation. When choosing plants for Washington, remember that soil pH varies statewide. Alkaline pH (i.e., above 7.0) soils with moderate salt levels can be found in the center part of the state, while more acidic (i.e., below 7.0) pH soils can be found west of the Cascades.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><em>Soil Preparation<\/em><\/h3>\n\n\n\n<p>Soils should be tested for pH, salinity (i.e., salts), texture, organic matter, and nutrient levels, since these represent common soil problems in Washington which should be identified and, if possible, addressed before planting. Installing a new landscape provides a unique opportunity to make major improvements to the soil before permanent vegetation is established and sprinkler systems and hardscape features are integrated. The soils in each planting zone should be considered separately, however, to ensure that the soil and improvement efforts are appropriate for the plants planned for that area. Refer to Chapter 3: Soil Science for more information on soil improvement.<\/p>\n\n\n\n<p>Generally, the better the topsoil, the better the conditions for plant growth. A minimum of four inches of topsoil is recommended for turf; eight inches for trees. Deep, uniform topsoil encourages deeper rooting and provides a larger reservoir of water for plant use. If additional soil is brought to the site, it should be placed in lifts (layers). Lay the first third of the new topsoil and thoroughly blend with the native soil on site to create a transitional layer. Place the remaining soil on top of this transitional layer.<\/p>\n\n\n\n<p>Compaction is a significant problem in new developments due to the activity of heavy equipment during construction. Break up compacted soil with a ripper blade or heavy-duty tiller before placing new topsoil and planting. The addition of organic matter on the surface may assist in loosening compacted soils over time.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><em>Soil Management<\/em><\/h3>\n\n\n\n<p>Along with plant selection, soil texture also dictates the frequency of watering and duration applied in the landscape. Sandy soils absorb water faster but have lower storage capacities than silt and clay soils. In general, sandy soils should be irrigated more frequently but in smaller amounts than silt and clay soils. Allowing irrigation water to penetrate deeper into the soil profile encourages deeper roots, resulting in a more drought-tolerant plant. Frequent, light irrigations will lead to plants with shallow root systems, making them more prone to water stress. However, in the case of newly planted trees and shrubs, more frequent and deep watering is necessary to promote good root establishment.<\/p>\n\n\n\n<p>Once the landscape has been established, various management practices can help maintain quality soil conditions and conserve water. For turfgrass, aeration is a common practice to improve water infiltration and aeration (i.e., gas exchange properties) in soil. Aeration removes small plugs of soil, creating air space and pathways for water movement into the root zone. Aeration should be done once a year in either the spring or fall in soils with a high clay content, or in situations where turf is exposed to heavy foot traffic.<\/p>\n\n\n\n<p>To maintain or improve soil physical conditions, annual planting areas, such as flowerbeds and gardens, can be amended with one-half inch to one inch of new organic matter each year. In perennial areas, such as turf and around trees and shrubs, organic matter cannot be incorporated without damaging roots. In these cases, top dressing with compost and mulch is recommended.<\/p>\n\n\n\n<h2 class=\"wp-block-heading  wsu-heading--style-marked\" id=\"ch25-plant-selection\">Plant Selection<\/h2>\n\n\n\n<p>One of the most pleasurable aspects of landscaping is choosing plants that appeal to you. Whether aesthetically, as with flowering plants, or practically, as with vegetables, plant selection is indicative of your personal taste. It is also important to select plant species that are adapted to the soil, water, temperature, light, and pest conditions of the landscape environment to help minimize maintenance and water requirements and encourage healthier plant growth. One suggested resource is the <a href=\"https:\/\/www.savingwater.org\/lawn-garden\/\" data-type=\"URL\" data-id=\"https:\/\/www.savingwater.org\/lawn-garden\/\" target=\"_blank\" rel=\"noreferrer noopener\">Saving Water Partnership (opens in new window)<\/a>, developed by the City of Seattle and participating area water utilities, which lists plants that are adapted to the Pacific Northwest. This site provides information on light level preferences (sun vs. shade) and mature plant heights, categorized as small, medium, or large. Other resources on selecting waterwise plants are listed in the Further Reading section of this chapter.<\/p>\n\n\n\n<p>Some morphological traits, or physical characteristics, are good indicators of plant adaptation to low water situations. Plants with smaller leaves or highly dissected leaves have evolved to reduce water loss through transpiration. Protective coverings, such as thick, waxy cuticles or pubescence (hairy) leaf surfaces, also serve to conserve water. Dense pubescence often makes plants appear gray-blue or gray-green. Plants have also evolved various root systems to cope with limited soil water. Some plants have a large taproot to scavenge water deeper in the soil. Others have a dense, fibrous root system to access soil moisture over a large area or volume of soil.<\/p>\n\n\n\n<h2 class=\"wp-block-heading  wsu-heading--style-marked\" id=\"ch25-turfgrass-placement\">Turfgrass Placement in the Landscape<\/h2>\n\n\n\n<p>Turfgrass covers most of the landscaped area in Washington. It is also the plant most often over-irrigated. For this reason, it is important to consider the placement of turfgrass.<\/p>\n\n\n\n<p>Avoid using turfgrass in areas that are hard to irrigate, such as steep slopes or oddly shaped or narrow spaces. Always consider if turfgrass is the best strategy for an area and consider alternatives that may be more water efficient or easier to maintain.<\/p>\n\n\n\n<p>One management strategy under low water conditions is to let the turfgrass go dormant during the hottest part of the growing season. Dormancy is the physiological process turfgrass undergoes to protect itself during drought and heat. Often, turfgrass that has turned a golden or brown color as it enters dormancy is mistaken for dying grass. However, as the temperatures begin to cool and more moisture is available, the grass will recover from dormancy.<\/p>\n\n\n\n<p>If you choose to let turfgrass go dormant, eliminate all traffic on it, including mowing. Mowing will not be necessary anyway, due to the reduced growth rate of the grass. Adjust the automatic irrigation timers or use hose-end sprinklers to apply approximately one inch of water per month. This is known as <a href=\"https:\/\/extension.wsu.edu\/pnw-gardeners-handbook\/glossary\/#s\" data-type=\"URL\" data-id=\"https:\/\/extension.wsu.edu\/pnw-gardeners-handbook\/glossary\/#s\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>survival watering<\/strong> (opens in new window)<\/a> and will be sufficient to maintain turfgrass through a drought period. When drought conditions subside, begin regular applications of water to bring the turfgrass out of its dormant state. If you let the turfgrass go dormant, remember that landscape plants nearby still require adequate irrigation.<\/p>\n\n\n\n<p>If the appearance of dormant turfgrass is not acceptable and you wish to maintain a green lawn, less water will be used if you reduce traffic to minimize wear and soil compaction. Also, reduce mowing frequency to avoid further stressing the turfgrass. Increasing mowing height will also aid root growth and reduce plant stress. Withhold fertilizers (particularly nitrogen) during dry periods.<\/p>\n\n\n\n<h2 class=\"wp-block-heading  wsu-heading--style-marked\" id=\"ch25-mulching\">Mulching<\/h2>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"alignright size-full is-resized\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/10\/Fig_02-6.jpg\" alt=\"Landscaped area beside a building with trees and shrubs planted in soil and mulch, showing how mulched areas reduce erosion and enhance appearance.\" class=\"wp-image-3816\" width=\"450\" height=\"300\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/10\/Fig_02-6.jpg 600w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/10\/Fig_02-6-300x200.jpg 300w\" sizes=\"(max-width: 450px) 100vw, 450px\" \/><figcaption class=\"wp-element-caption\">Figure 2. Landscape plantings without mulch show signs of soil erosion and drying. Mulched areas add visually to the landscape. Photo: R. Koenig.<\/figcaption><\/figure><\/div>\n\n\n<p>Mulching is the process of maintaining a relatively thick, continuous layer of material, such as bark, wood chips, or decorative rock, on the soil surface. Mulching is fundamentally different than amending soil with organic matter: amending refers to the incorporation of organic matter into the soil, whereas mulch is layered over the soil.<\/p>\n\n\n\n<p>Mulch reduces moisture loss from the soil and promotes rooting near the surface. Greater rooting near the soil surface increases water, nutrient, and oxygen absorption, leading to healthier plants. Mulches can also moderate surface soil temperatures, control annual weeds and grasses, reduce weed seed germination, decrease runoff and soil erosion, protect the trunk of woody vegetation from mower damage, and allow easier movement through landscapes and gardens during wet periods. Properly used, mulch also improves the aesthetics of a landscape (Figure 2).<\/p>\n\n\n\n<p>Organic mulches include plant-derived materials, such as bark, straw, leaves, or arborist chips. Inorganic mulches include landscape fabric and decorative rocks. Organic mulches have the advantage of supplying all or part of the nutrients required by plants, moderating soil temperatures, and supporting healthy soil biota and mycorrhizal fungi; however, organic mulches decompose and require replenishing where maturing plants have not yet filled in. Inorganic mulches do not provide nutrient benefits but may last longer than organic materials. Choice of mulch material should be based on personal values, cost, availability, and the desired physical, chemical, and visual effects (see sidebar Characteristics of Some Commonly Used Mulch Materials).<\/p>\n\n\n\n<p>Mulches are applied after seedling emergence or after transplanting. The thickness of your mulch layer will vary depending on the material used. To get the maximum benefit from mulching, apply 1 to 2 inches of fine, dense material (less than \u00bd-inch diameter) or 3 to 6 inches of course, fluffy material (between \u00bd inch and 3 inches in diameter). Note: a one-inch-thick layer of mulch requires approximately 3 cubic yards of material per 1,000 square feet of area. Distribute mulch evenly around the base of plants but avoid having mulch directly against stems. Avoid packing mulches, especially if the material is wet when applied. Maintain as much air space in the mulch material as possible to allow for oxygen movement to roots.<\/p>\n\n\n\n<p>Mulch layers should be maintained at their prescribed thickness. As organic mulches decompose (and the layer shrinks), add new material. The decomposition of organic mulch releases nutrients. Also, insects and other soil organisms live and feed in the mulch, incorporating organic matter into the soil beneath the mulch layer.<\/p>\n\n\n<div class=\"wsu-callout wsu-border--color-vineyard wsu-callout--style-basic wsu-color-background--gray-5 wsu-border--add-left wsu-align-item--center wsu-spacing-after--large wsu-spacing-before--large wsu-max-width--xxmedium\" >\r\n        \n\n<h3 class=\"wp-block-heading has-text-align-center  wsu-font-size--xxmedium\">Characteristics of Some Commonly Used Mulch Materials<\/h3>\n\n\n\n<p class=\"wsu-font-size--medium\">Wood chips, arborist chips, and barks\u2014These materials can tie up nitrogen in soil and induce a nitrogen deficiency in plants.<\/p>\n\n\n\n<p class=\"wsu-font-size--medium\">Straw, leaves, and grass hay\u2014Chop or shred material before use to create a better mulch.<\/p>\n\n\n\n<p class=\"wsu-font-size--medium\">Lawn clippings\u2014Do not use fresh clippings as mulch. Dry or compost clippings first.<\/p>\n\n\n\n<p class=\"wsu-font-size--medium\">Compost\u2014Test for high levels of soluble salts and high pH before using as a mulch. May also promote the growth of weed seeds from nearby weeds.<\/p>\n\n\n\n<p class=\"wsu-font-size--medium\">Legume hay\u2014May heat upon wetting. Compost first or mix with other mulches before using.<\/p>\n\n\n\n<p class=\"wsu-font-size--medium\">Plastics\u2014May generate excessively high soil temperatures if in direct sunlight during midsummer. Cover plastic with other decorative mulches during hot periods. Will not decompose and may cause future problems as landscape is altered.<\/p>\n\n\n\n<p class=\"wsu-font-size--medium\">Landscape fabrics\u2014Effective in weed suppression and allows for water and air penetration into soil. Spread the fabric over the soil, cut holes for existing or new plants, then cover the fabric with a mulch, such as bark, gravel, or other material. Will not decompose and may cause future problems as landscape is altered.<\/p>\n\n\n\n<p class=\"wsu-font-size--medium\">Rocks\u2014May generate high soil temperatures during midsummer.<\/p>\n\n<\/div>\r\n\n\n\n<h2 class=\"wp-block-heading  wsu-heading--style-marked\" id=\"ch25-irrigation-planning\">Irrigation Planning and Practices<\/h2>\n\n\n\n<p>Water is essential to plants. Unless plant roots have a continuous supply, the plant will eventually wilt. Some exposure of a plant to water stress can increase its ability to withstand drought. Eventually, however, if water is not added to reverse wilting, the plant will die. It should be noted that most plants need more water during the establishment period and that supplemental irrigation can be curtailed once plants have established. The establishment period varies among species. Turf may only take a few months, while trees and shrubs may take one to three years.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><em>Hydrozoning<\/em><\/h3>\n\n\n\n<p>The first step toward properly irrigating plants is arranging them into <a href=\"https:\/\/extension.wsu.edu\/pnw-gardeners-handbook\/glossary\/#h\" data-type=\"URL\" data-id=\"https:\/\/extension.wsu.edu\/pnw-gardeners-handbook\/glossary\/#h\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>hydrozones<\/strong> (opens in new window)<\/a> according to their water requirements. This could be a specific area of the landscape or an area under the control of a specific zone of the irrigation system. Once plants are arranged into hydrozones, schedule the irrigation to apply the appropriate amount of water to each of the zones.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><em>Assessing When to Water<\/em><\/h3>\n\n\n\n<p>The optimum time to water is before you observe any stress on plants from lack of water. Monitoring plant condition and soil moisture can help determine when irrigation is needed.<\/p>\n\n\n\n<p>It is possible to measure or estimate the amount of water lost from the landscape in order to predict how much water needs to be replaced. This is known as irrigating based on <a rel=\"noreferrer noopener\" href=\"https:\/\/extension.wsu.edu\/pnw-gardeners-handbook\/glossary\/#e\" data-type=\"URL\" data-id=\"https:\/\/extension.wsu.edu\/pnw-gardeners-handbook\/glossary\/#e\" target=\"_blank\"><strong>evapotranspiration<\/strong> (opens in new window)<\/a> (ET). Evapotranspiration is the sum of the water lost from the soil surface through evaporation plus the water lost through transpiration from the plant. This method is specific for plant species and climatic conditions, such as temperature, humidity, and wind. Refer to <a href=\"https:\/\/region8water.colostate.edu\/PDFs\/hg523.pdf\" data-type=\"URL\" data-id=\"https:\/\/region8water.colostate.edu\/PDFs\/hg523.pdf\" target=\"_blank\" rel=\"noreferrer noopener\">Efficient Irrigation of Trees and Shrubs (links to PDF document)<\/a> in the Further Reading section of this chapter for more information on ET.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><em>Visual Signs<\/em><\/h3>\n\n\n\n<p class=\"wsu-spacing-after--large\">Visual signs such as wilting are good indicators that landscape plants need water. Wilting and leaf scorch are both symptoms of water stress (Figure 3). However, overwatering plants can create similar browning symptoms and even cause the leaves to senesce. Roots need oxygen to survive, and when the soil is saturated with water, oxygen levels in the root zone are reduced. Without a healthy root system the plant is unable to absorb water and will show signs of water stress. Many gardeners assume stress symptoms are from a lack of water and will compound the problem by overwatering, eventually causing the plant to die.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large wsu-spacing-after--large\"><img decoding=\"async\" loading=\"lazy\" width=\"1024\" height=\"512\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/10\/Fig_03_LR-1024x512.jpg\" alt=\"Two close-up photos showing water stress symptoms on tree leaves: left, California buckeye leaves with brown, dry edges; right, littleleaf linden leaves with browned, curled margins.\" class=\"wp-image-3818\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/10\/Fig_03_LR-1024x512.jpg 1024w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/10\/Fig_03_LR-300x150.jpg 300w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/10\/Fig_03_LR-768x384.jpg 768w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/10\/Fig_03_LR.jpg 1200w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Figure 3. Symptoms of water stress on a California buckeye, (<em>Aesculus californica<\/em>) (left photo) and littleleaf linden (<em>Tilia cordata<\/em>) (right photo). Left photo by Jim Kropf, right photo by R. Koenig.<\/figcaption><\/figure>\n\n\n\n<p>Trees and shrubs have much deeper root systems than turfgrass; therefore, depending on the size and type of tree or shrub, they should be watered to a soil depth of at least 18 to 24 inches. In general, trees and shrubs should be watered less frequently than turfgrass but for longer periods of time (i.e., deeper watering).<\/p>\n\n\n\n<p>Trees and shrubs located in turfgrass areas benefit from normal lawn irrigation. However, during the months of July and August, a deep watering one to three times per month using either the turfgrass irrigation system or watering by hand may be needed where trees and shrubs are growing in turfgrass areas. Arborists, however, recommend a two- to four-inch layer of mulch under the drip line of trees instead of turf. See Chapter 12: Trees and Woody Landscape Plants for more details.<\/p>\n\n\n\n<p><strong>Feel method<\/strong>. This method involves feeling a handful of soil to evaluate its moisture level. Sandy and loam soils are considered dry, with little or no available moisture for the plant, when the soil runs through your fingers and no stain remains on your hands. Clay soils are hard to break apart when they are dry. When moisture levels are optimum for plants, you should be able to form an intact ball of soil and a thin layer of moisture and stain will be left on your hands. If water seeps out of the soil ball, it contains more than adequate amounts of moisture and should not be irrigated.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"alignright size-full is-resized\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/10\/Fig_04-11.jpg\" alt=\"Person holding a soil probe and a tile probe over grass, showing about six inches of soil moisture penetration depth.\" class=\"wp-image-3820\" width=\"450\" height=\"300\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/10\/Fig_04-11.jpg 600w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/10\/Fig_04-11-300x200.jpg 300w\" sizes=\"(max-width: 450px) 100vw, 450px\" \/><figcaption class=\"wp-element-caption\">Figure 4. Soil probe (top) and tile probe (bottom) indicate similar depths of water movement (about six inches in this example). Photo: R. Koenig.<\/figcaption><\/figure><\/div>\n\n\n<p><strong>Probe method<\/strong>. Soil probes can be used to determine soil moisture and watering depth. The advantage of probes is that they allow rapid inspection of conditions beneath the soil surface with minimal disturbance. Probes can also be used to check for compaction in lawns, tree planting holes, and gardens. There are two main types of probes: the tile probe and the open-faced probe.<\/p>\n\n\n\n<p class=\"wsu-spacing-after--large\">A tile probe is a solid metal rod with a pointed tip fixed to a handle. These probes are inserted into the soil but do not allow a sample to be removed (Figure 4). Inexpensive tile probes can be constructed from a \u00bc-inch diameter rolled steel rod welded to a 12-inch long section of 1-inch diameter metal pipe as a handle.<\/p>\n\n\n\n<p>Use a tile probe one to two hours after irrigating to monitor the depth of water movement. A tile probe enters moist soil easily. Resistance increases noticeably when the probe encounters dry soil. Stop applying pressure when resistance increases to a level where the probe begins to flex. Grasp the probe at ground level and remove it, noting how much of the probe was below the surface. This is an estimate of the depth of water movement. Sample in several locations to estimate the average depth of water movement. Using tile probes takes some practice; however, once you are accustomed to these devices you can rapidly and accurately assess the depth of water movement in soil. Do not use probes in areas where utility lines are located, and use them carefully around sprinkler lines. If you do not know the location of utility lines, contact 811 to have your utilities marked out.<\/p>\n\n\n\n<p>An open-faced probe can be used to remove intact soil cores. Before irrigating, sample in several locations and inspect the soil to determine if it is dry or still moist from the previous irrigation. Between one and two hours after irrigating, remove intact soil cores from several locations and look for a color change between wet (dark) and dry (light) soil (Figure 4). This dark\/light color change indicates the depth of water movement in soil, or the <a href=\"https:\/\/extension.wsu.edu\/pnw-gardeners-handbook\/glossary\/#w\" data-type=\"URL\" data-id=\"https:\/\/extension.wsu.edu\/pnw-gardeners-handbook\/glossary\/#w\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>wetting front depth<\/strong> (opens in new window)<\/a>.<\/p>\n\n\n\n<p>Soil probes can also be used to monitor the uniformity of irrigation and determine if maintenance and improvements might be needed. Check the wetting front depth around and between sprinkler heads. If the depth varies, inspect sprinkler output rates and water distribution.<\/p>\n\n\n\n<p>When water is applied frequently and for just short periods of time, it is common for soil to be wet to a depth of only a few inches. Over time, short, shallow watering limits plant rooting depth to a shallow surface layer. Additional water is needed to wet the soil to a greater depth to encourage deeper rooting. Less frequent but longer irrigation will achieve this. If the depth of wetting exceeds 18 inches, the water is likely to move beyond the roots of many plants. For lawns, 6 to 12 inches of moist soil is sufficient. Gardens and established trees often root deeper than turf and can benefit from less frequent irrigations, applied less often. A wetting depth of around 24 inches is a good goal for trees.<\/p>\n\n\n\n<p>Soil probes can be purchased at certain landscape supply outlets as well as from mail-order sources. Some suggestions, such as Forestry Suppliers, Inc., are located at the end of the chapter.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><em>Irrigation Scheduling<\/em><\/h3>\n\n\n\n<p>An irrigation schedule should be devised and then monitored throughout the year as part of a comprehensive irrigation plan. Less water is lost from plants and soil during the cooler spring and fall months, so less irrigation water is needed at those times. Water is wasted when automatic irrigation systems are programmed for the hottest part of the summer without adjusting for times of day when temperatures are cooler and more natural precipitation is occurring. Water between 6 p.m. and 10 a.m. to minimize water losses due to evaporation. Note that to prevent mildew and other wetness-related diseases and problems, watering between 4 a.m. and 10 a.m. minimizes the amount of time for water-foliage contact. Websites listed at the end of this chapter, such as <a href=\"http:\/\/irrigation.wsu.edu\/\" data-type=\"URL\" data-id=\"http:\/\/irrigation.wsu.edu\/\" target=\"_blank\" rel=\"noreferrer noopener\">Irrigation in the Pacific Northwest (opens in new window)<\/a> and <a href=\"https:\/\/weather.wsu.edu\/\" data-type=\"URL\" data-id=\"https:\/\/weather.wsu.edu\/\" target=\"_blank\" rel=\"noreferrer noopener\">AgWeatherNet (opens in new window)<\/a>, provide further information.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"alignright size-full is-resized\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/10\/Fig_05-10.jpg\" alt=\"Lawn with irregular brown patches and green spots caused by uneven irrigation from low water pressure.\" class=\"wp-image-3821\" width=\"450\" height=\"300\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/10\/Fig_05-10.jpg 600w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/62\/2025\/10\/Fig_05-10-300x200.jpg 300w\" sizes=\"(max-width: 450px) 100vw, 450px\" \/><figcaption class=\"wp-element-caption\">Figure 5. Brown patches in turfgrass areas due to low water pressure and poor uniformity of application. Photo: R. Koenig.<\/figcaption><\/figure><\/div>\n\n\n<h3 class=\"wp-block-heading\"><em>Irrigation Maintenance<\/em><\/h3>\n\n\n\n<p>Routine maintenance of an irrigation system is essential. In early spring, prior to using an irrigation system, perform general maintenance to ensure the system is providing uniform coverage of the turfgrass, gardens, or ornamental areas (Figure 5). This is a good time to identify and repair broken or damaged sprinkler heads and nozzles and adjust sprinkler heads that are tilted or buried too deeply.<\/p>\n\n\n\n<p>Confirm the application rate of the irrigation system to help determine the irrigation run times required to apply the desired amount of water. One way to measure the irrigation rate is to space metal cans or straight-sided catch cups uniformly around the landscape. Run the irrigation system for at least 15 minutes and then measure the depth of water in each can to determine the output rate (depth in inches divided by time in minutes) and the distribution uniformity of your irrigation system.<\/p>\n\n\n\n<p>Monthly examination of the irrigation system while in use will help to identify and repair any broken, misaligned, or clogged sprinkler heads and keep the system running efficiently.<\/p>\n\n\n\n<p class=\"wsu-spacing-after--xsmall\">Other water-efficient irrigation practices include:<\/p>\n\n\n\n<ul>\n<li>Watering between 6 p.m. and 10 a.m. to minimize water losses due to evaporation. Note that to prevent mildew and other wetness-related diseases and problems, watering between 4 a.m. and 10 a.m. minimizes the amount of time for water-foliage contact.<\/li>\n\n\n\n<li>Set the irrigation system to run in cycles instead of applying all the water at once to avoid oversaturation and runoff.<\/li>\n\n\n\n<li>Shut off automatic systems on rainy or windy days.<\/li>\n\n\n\n<li>Aim the sprinkler heads correctly: water the landscape, not the sidewalks.<\/li>\n\n\n\n<li>Hand-water individual plants for an adequate length of time.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading  wsu-heading--style-marked\" id=\"ch25-landscape-maintenance\">Landscape Maintenance<\/h2>\n\n\n\n<p class=\"wsu-spacing-after--xsmall\">One of the most important components of managing a beautiful and lasting landscape is maintenance. Maintenance practices for conserving water in the landscape include:<\/p>\n\n\n\n<ul>\n<li>Managing and removing weeds to reduce competition for water. Consider close plant spacing to crowd weeds out.<\/li>\n\n\n\n<li>Covering all bare soil: mulch to reduce water evaporation from the soil and reduce weeds. Mulch also slows runoff and allows for greater infiltration.<\/li>\n\n\n\n<li>Fertilizing conservatively or using slow-release products to eliminate excessive flushes of growth that require more water.<\/li>\n\n\n\n<li>Regularly mowing turfgrass, cutting no more than one-third of the grass-blade, using a mulching mower on a high setting. This would take advantage of the mulch provided by the clippings.<\/li>\n\n\n\n<li>Pruning landscape plants to reduce leaf surface area and transpiration.<\/li>\n\n\n\n<li>Aerating turf areas to relieve soil compaction, encourage better water penetration, and prevent runoff.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\" \/>\n\n\n\n<h2 class=\"wp-block-heading  wsu-heading--style-marked\" id=\"ch25-further-reading\">Further Reading<\/h2>\n\n\n\n<p><a href=\"https:\/\/pubs.extension.wsu.edu\/\" data-type=\"URL\" data-id=\"https:\/\/pubs.extension.wsu.edu\/\" target=\"_blank\" rel=\"noreferrer noopener\">WSU Extension publications (opens in new window)<\/a>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><em>WSU Extension Publications<\/em><\/h3>\n\n\n\n<p><a href=\"https:\/\/weather.wsu.edu\/\" target=\"_blank\" rel=\"noreferrer noopener\">AgWeatherNet (opens in new window)<\/a>. 2024. Washington State University.<\/p>\n\n\n\n<p>Brun, C. 2015. <a href=\"https:\/\/pubs.extension.wsu.edu\/drought-tolerant-landscaping-for-washington-state-home-garden-series\" target=\"_blank\" rel=\"noreferrer noopener\">Drought Tolerant Landscaping for Washington State (opens in new window)<\/a> (Home Garden Series). <em>Washington State University Extension Publication<\/em> EM087E. Washington State University.<\/p>\n\n\n\n<p><a href=\"https:\/\/irrigation.wsu.edu\/\" target=\"_blank\" rel=\"noreferrer noopener\">Irrigation in the Pacific Northwest (opens in new window)<\/a>. 2024. Prosser Irrigated Agriculture Research and Extension Center. <em>An informational website focused on helping growers learn about water management in Washington, Idaho, and Oregon<\/em>.<\/p>\n\n\n\n<p>Maleike, R., and M. Ophardt. 2001. <a href=\"https:\/\/pubs.extension.wsu.edu\/drought-advisory-water-conservation-in-gardens-and-landscapes\" target=\"_blank\" rel=\"noreferrer noopener\">Water Conservation in Gardens and Landscapes (opens in new window)<\/a>. <em>Washington State University Extension Publication<\/em> EM4834. Washington State University.<\/p>\n\n\n\n<p>Peters, T. 2009. <a href=\"https:\/\/pubs.extension.wsu.edu\/washington-water-rights-for-agricultural-producers\" target=\"_blank\" rel=\"noreferrer noopener\">Washington Water Rights for Agricultural Producers (opens in new window)<\/a>. <em>Washington State University Extension Publication<\/em> FS014E. Washington State University.<\/p>\n\n\n\n<p>Pinyuh, G., M. Ophardt, and R. Maleike. 2002. <a href=\"https:\/\/pubs.extension.wsu.edu\/watering-home-gardens-and-landscape-plants\" target=\"_blank\" rel=\"noreferrer noopener\">Watering Home Gardens and Landscape Plants (opens in new window)<\/a>. <em>Washington State University Extension Publication<\/em> EB1090. Washington State University.<\/p>\n\n\n\n<p>Simmons, R., A. Jayakaran, D. McNamara, C. Thompson, B. Boyd, and E. Guttman. 2022. <a href=\"https:\/\/ruralstormwater.wsu.edu\/\" target=\"_blank\" rel=\"noreferrer noopener\">Rural Stormwater Solutions (opens in new window)<\/a>. Washington State University.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Other Resources:<\/h3>\n\n\n\n<p>Cerny, T.A., R. Hefelbower, L.A. Sagers, and W. Bitner. 2003. <a href=\"https:\/\/digitalcommons.usu.edu\/cwel_extension\/20\" target=\"_blank\" rel=\"noreferrer noopener\">Water-Wise Plants for Utah Landscapes (opens in new window)<\/a>. <em>Center for Water-Efficient Landscaping Extension Publication<\/em> Paper 20. Utah State University.<\/p>\n\n\n\n<p>Cerny, T., M. Kuhn, K.L. Kopp, and M. Johnson. 2002. <a href=\"https:\/\/region8water.colostate.edu\/PDFs\/hg523.pdf\" data-type=\"URL\" data-id=\"https:\/\/region8water.colostate.edu\/PDFs\/hg523.pdf\" target=\"_blank\" rel=\"noreferrer noopener\">Efficient Irrigation of Trees and Shrubs (links to PDF document)<\/a>. <em>Utah State University Extension Publication<\/em> HG-523. Utah State University.<\/p>\n\n\n\n<p><a href=\"https:\/\/www.forestry-suppliers.com\/\" target=\"_blank\" rel=\"noreferrer noopener\">Forestry Suppliers, Inc. 2024 (opens in new window)<\/a>. Homepage. <em>Source for soil probes<\/em>.<\/p>\n\n\n\n<p>Keane, T. 1995. <a href=\"https:\/\/digitalcommons.usu.edu\/extension_histall\/975\/\" target=\"_blank\" rel=\"noreferrer noopener\">Water-Wise Landscaping: Guide for Water Management Planning (opens in new window)<\/a>. Utah State University Extension.<\/p>\n\n\n\n<p>Knopf, J. 1999. <em>Waterwise Landscaping with Trees, Shrubs, and Vines: A Xeriscape Guide for the Rocky Mountain Region, California, and the Desert Southwest<\/em>. Chamisa Books.<\/p>\n\n\n\n<p>Kopp, K.L., T. Cerny, and R. Hefelbower. 2002. <a href=\"https:\/\/region8water.colostate.edu\/PDFs\/hg518.pdf\" target=\"_blank\" rel=\"noreferrer noopener\">Water-Wise Landscaping (links to PDF document)<\/a>. <em>Utah State University Extension Publication<\/em> HG-518. Utah State University.<\/p>\n\n\n\n<p><a href=\"https:\/\/savingwater.org\/\" target=\"_blank\" rel=\"noreferrer noopener\">Saving Water Partnership (opens in new window)<\/a>. n.d. Homepage. <em>A service of Seattle and participating area water utilities<\/em>.<\/p>\n\n\n\n<p><a href=\"https:\/\/tilthalliance.org\/resources\/water-smart-watering\/\" data-type=\"URL\" data-id=\"https:\/\/tilthalliance.org\/resources\/water-smart-watering\/\" target=\"_blank\" rel=\"noreferrer noopener\">Seattle Tilth\u2014Water Smart Tool Kit (opens in new window)<\/a>.<\/p>\n\n\n\n<p>Steinegger, D., R. Gaussoin, and G. Horst. 1993. <a href=\"https:\/\/digitalcommons.unl.edu\/extensionhist\/1059\/\" target=\"_blank\" rel=\"noreferrer noopener\">Evaluating Your Landscape Irrigation System (opens in new window)<\/a>. <em>University of Nebraska-Lincoln Extension Publication<\/em> G93-1181. University of Nebraska-Lincoln.<\/p>\n\n\n\n<p>Stryker, J. 2022. <a href=\"https:\/\/www.irrigationtutorials.com\/\" target=\"_blank\" rel=\"noreferrer noopener\">Landscape Irrigation Tutorials (opens in new window)<\/a>.<\/p>\n\n\n\n<p><a href=\"https:\/\/planthardiness.ars.usda.gov\/PHZMWeb\/\" target=\"_blank\" rel=\"noreferrer noopener\">USDA Plant Hardiness Zone Map (opens in new window)<\/a>. n.d. 2023 USDA Plant Hardiness Zone Map.<\/p>\n\n\n\n<p><a href=\"https:\/\/conservewater.utah.gov\/\" target=\"_blank\" rel=\"noreferrer noopener\">Utah Division of Water Resources (opens in new window)<\/a>. n.d. Conserve Water.<\/p>\n\n\n\n<p>WaterRight. 2021. Homepage. <em>An educational and irrigation scheduling resource for water managers<\/em>.<\/p>\n\n\n\n<p><a href=\"https:\/\/www.waterstewardship.org\/\" target=\"_blank\" rel=\"noreferrer noopener\">Water Wise (opens in new window)<\/a>. n.d. City of Spokane Water Department.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Bob Simmons, Associate Professor of Water Resources, Washington State University Teresa C. Koenig, Adjunct Faculty Member, Department of Horticulture, Washington State University Richard Koenig, Professor, Department of Crop and Soil Sciences, Washington State University Excerpted and adapted with permission from material published by the authors while they were members of the faculty at Utah State [&hellip;]<\/p>\n","protected":false},"author":241,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_wsuwp_accessibility_report":null},"categories":[],"tags":[],"_links":{"self":[{"href":"https:\/\/extension.wsu.edu\/pnw-gardeners-handbook\/wp-json\/wp\/v2\/pages\/1661"}],"collection":[{"href":"https:\/\/extension.wsu.edu\/pnw-gardeners-handbook\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/extension.wsu.edu\/pnw-gardeners-handbook\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/extension.wsu.edu\/pnw-gardeners-handbook\/wp-json\/wp\/v2\/users\/241"}],"replies":[{"embeddable":true,"href":"https:\/\/extension.wsu.edu\/pnw-gardeners-handbook\/wp-json\/wp\/v2\/comments?post=1661"}],"version-history":[{"count":31,"href":"https:\/\/extension.wsu.edu\/pnw-gardeners-handbook\/wp-json\/wp\/v2\/pages\/1661\/revisions"}],"predecessor-version":[{"id":4778,"href":"https:\/\/extension.wsu.edu\/pnw-gardeners-handbook\/wp-json\/wp\/v2\/pages\/1661\/revisions\/4778"}],"wp:attachment":[{"href":"https:\/\/extension.wsu.edu\/pnw-gardeners-handbook\/wp-json\/wp\/v2\/media?parent=1661"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/extension.wsu.edu\/pnw-gardeners-handbook\/wp-json\/wp\/v2\/categories?post=1661"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/extension.wsu.edu\/pnw-gardeners-handbook\/wp-json\/wp\/v2\/tags?post=1661"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}