Water Landscaping
You can design a landscape that conserves water as well as energy. For tips on how to incorporate energy- and water-saving techniques into your landscaping, explore the Energy Saver 101 infographic on landscaping. Here is a brief overview of some water-conserving landscaping strategies.
Water Landscaping
If you can determine how much water your plants actually need, then you won't overwater them and waste water. It is important to not only understand a plant's particular watering requirements, but also evapotranspiration.
Evapotranspiration (Et) is the amount of water that is evaporated from the soil and transpired through the plant's leaves. This amount of water needs to be replaced through watering. If you know your area's Et rate, you can plan the amount of water to be replaced through irrigation. Call your local water district or cooperative extension service and ask about your Et rate or request an on-site water assessment (if available in your area). Your particular microclimate will also affect evapotranspiration in different areas of your yard.
Xeriscaping is a systematic method of promoting water conservation in landscaped areas. Although xeriscaping is mostly used in arid regions, its principles can be used in any region to help conserve water. Here are seven basic xeriscaping principles:
If you live in Utah, you have undoubtedly heard that Utah is one of the driest states in the nation, second only to Nevada. This fact, along with our relatively high level of water consumption and our population growth, has brought water conservation to the forefront of those natural resource issues currently facing the state.
In Utah, approximately 65% of our annual culinary water consumption is applied to landscapes. Our irrigated landscapes provide us with many benefits that include beautiful surroundings, natural cooling, and the cleansing of our environment.
However, Utah landscapes are often over-irrigated and a great deal of water conservation may be achieved by keeping a few water-wise landscaping principles in mind as we design, install, and manage our landscapes.
Conserving water in the landscape 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.
When choosing plants, identify their water requirements and group those with similar irrigation requirements in the same area or irrigation zone. This will help to more accurately meet plant water needs while conserving water. Zones can be separated into zone 0 (no irrigation), zone 1 (irrigate monthly), zone 2 (irrigate twice per month), zone 3 (irrigate weekly) and zone 4 (irrigate twice per week).
Plants adapted to the dry conditions of Utah will survive with little or no water (zone 0). It is important to know the water requirements of the plants at the site to most efficiently meet these needs without wasting water. The watering zone designs will depend on the amount of water you wish to use for the landscape, how much money you can spend on landscape water, and what you wish to achieve aesthetically and environmentally.
The types of plants that you are growing will have a bearing on the characteristics you require from a soil, but there are some general guidelines to follow. Using plant species that are adapted to the soil will help minimize maintenance and water required.
Plant selection is a fun part of the design process for most people and selecting the right plant for the right place is essential for creating a water-efficient landscape. Visit local water-wise demonstration gardens to get ideas for plant combinations and mature sizes. The following water-wise plant lists were created for arid Utah landscapes.
Lawns have many benefits including cooling effects, erosion control, water filtration and water infiltration. Lawns can withstand trampling and play that no other plant can handle. Lawns also need a lot less water than they are given.
An average golf course, for example, can absorb 4 million gallons of water during a 1-inch rainstorm. A golf course or turf area can absorb far more than one inch of rain water without runoff, assuming it's not coming down too quickly. This is because a dense turf area can reduce runoff to virtually nothing. And when compared to a non-turf area (like a garden or agricultural field), grass areas can reduce runoff-induced soil erosion by up to 600 times (Whiting, et al., 2005).
Turfgrass can be a practical and beautiful component of a water-wise landscape. As a design component, turfgrass invites participation in the landscape while providing unity and simplicity (Welsh, 2001).
Mulch can provide many benefits in water-wise landscapes. Mulch covers the soil and prevents crusting, compaction, and water evaporation, while also providing an important visual design aspect. Choosing the right mulch for the situation is dependent on plant selection, watering regime and site use.
Mulch can provide many benefits in water-wise landscapes. Mulch covers the soil and prevents crusting, compaction, and water evaporation. In fact, mulching around trees, shrubs, and in flower beds can result in a ten-fold reduction in evaporative water loss from soil.
Reducing soil water loss means more water is available to plants and less water needs to be provided. Mulch also reduces the number of weeds in a water-wise landscape by preventing light-induced germination of weed seeds. With fewer weeds, less cultivation is required, which can prevent damage to plant roots, soil structure, and soil organisms. In addition, mulch moderates soil temperature and protects plant roots.
In winter, moderation of soil temperature can prevent plants from heaving out of the ground due to freezing and thawing. Mulch also can be an important visual design element in a water-wise landscape, and it is used along walkways, in plant borders, and for color and structure in a landscape or garden.
Mulch is a great way to recycle yard waste, such as pruned woody plant materials, fallen leaves and needles, and even grass clippings. To ensure adequate water infiltration and aeration and to slow decomposition, make sure mulch particles are larger than the underlying soil particles (usually larger than a half inch in diameter).
Over time, organic mulches break down and will need to be replenished. Replenishment can be accomplished simply by adding more mulch over the top of the decomposed mulch material. Before adding new mulch, roughen up the old mulch layer to prevent formation of a water-impervious surface between old and new mulch.
A weed barrier may be placed on the soil surface before using either organic or inorganic mulch material. The best choices are landscape fabrics of various types that allow air exchange and water infiltration.
In Utah, urban landscape irrigation accounts for 50-65% of the annual municipal water use, and much of it is applied in excess of the plant's needs. Scheduling irrigation according to landscape plant water needs can reduce excess water use. In addition to conserving water, proper irrigation can encourage deeper root growth and healthier, more drought tolerant landscapes.
An important component of water-efficient landscaping is creating hydrozones for your irrigation needs. To provide adequate water to all plants without over or under-watering some, group plants with similar irrigation needs in one zone.
Once your plants are grouped into zero, low, medium and high water groups, you should plan your irrigation schedule to apply the appropriate amount of water to each zone. You can learn a great deal about plant-water requirements simply by observation.
A great deal of water is wasted when automatic irrigation systems are continually programmed for the hottest part of the summer without adjusting for times when temperatures are cooler and more natural precipitation is occurring.
Drip Irrigation systems consists of plastic pipes with emitters that deliver water directly to plants. These types of systems are great for water-efficient landscapes as water goes directly to the plants roots and is not wasted on areas that do not need to be watered.
Turfgrass has shallower roots than other landscape plants and therefore should be irrigated more frequently, but not as deeply as other landscape plants. Consider using turfgrasses with lower water requirements to reduce water use even further.
Plan and design irrigation systems so that turfgrass areas are irrigated separately from other landscape plants. There are several resources available to determine the appropriate watering schedule for turf areas in Utah.
Trees and shrubs have much deeper and more extensive root systems than turfgrass so they should be watered less frequently but for longer periods of time. The optimum time to water is just before you can observe any water stress. Therefore, it is important to determine sub-surface soil moisture. Soil moisture can be determined using a soil moisture probe.
Sandy soils absorb water the fastest (about 2" per hour), followed by loam soils (3/4" per hour). Clay soils have the slowest absorption rate (1/2"per hour). By allowing water to penetrate deeper into the soil profile, you are encouraging deeper rooting and a more drought tolerant plant.
Frequent, light irrigation will lead to plants that have a shallow root system and that are more prone to water stress. When using sprinkler systems about 1/2 -1 inch of water may be required weekly for shrubs and smaller trees (
These amounts would be higher in southern Utah and lower in northern Utah and would also depend on plant size. Large trees (>4" trunk diameter), depending on the size of the tree, may require hundreds of gallons of water per week. Water newly planted trees and shrubs more frequently until the root system is established.
Irrigation system maintenance is necessary to ensure the most efficient use of water that is being applied. Irrigation controllers should be checked at the beginning of each growing season before running sprinklers for the first time. 041b061a72