What is Xeriscaping? By Sunrise Inc.
Xeriscaping is creatively using landscaping to conserve water usage. Although developed for drought areas or areas with low availability of water it is not exclusively for these areas. Today, Xeriscapes exist in almost every state. Xeriscapes can be used anywhere to conserve water. Residential water usage for landscaping can be reduced as much as 60%. This plus reducing the cost of maintaining the landscape an also adds value to the home and property.
The term Xeriscape is derived from a combination of the words “xeri” and “scape”. The work “xeri” comes fro the Greek work “xeros” which means dry. “Scape” means scene. Even though this translates into “dry scene” it does not accurately reflect the results or the impact of Xeriscaping. There are many aspects to Xeriscaping but at its essence it involves the use of plant materials that are appropriate for the region or to the water availability. This frequently means the use of native plants.
Xeriscape does not mean barren, desert, arid, or any other form of plant material that you might associate with dry climates. The picture below shows a lush display of plants that are compatible with their environment and are part of a well planned Xeriscape.
The seven principles of Xeriscaping deal with specific features of the landscape. However, traditional landscape design concepts still apply. Xeriscape concepts can be applied to any style of design. The same results can be achieved using a Xeriscape approach. The mixture of design elements may be different but the desired theme or style can still be achieved.
The seven principles are:
- Planning and Designing
- Soil Analysis & Improvement
- Plant Selection
- Use of Turf
- Efficient Irrigation
- Use of Mulches
- Maintenance
Each of the seven principles is a common sense way to be more water efficient. The more of the seven principles that are applied, the more water efficient the landscape becomes. The seven principles must also be considered together. Each principle may be related to one or more of the other principles.
Regardless whether you are gradually updating an existing landscape, completely redoing an existing landscape, or starting with a brand new landscape, planning and design are important. Basic landscape design principles are still applied when creating a Xeriscape. You will want to analyze your site and note its characteristics.
For example, noting the orientation will help you determine where the sun areas are located. The shade areas will lose less water from evaporation due to the reduced heat. The creative use of shade will allow you to control water usage and reduce the temperature of the various areas of the landscape.
You should also look at the different soil areas. Are some areas wet? Are others dry? What is the soil itself like? Is it clay, sandy, or some other type? All of these observations and notes should be recorded to help you later during the Soil Analysis sample principle.
Your design should also take into account the different use areas. Public areas that are highly visible tend to have more decorative, varied, and ornamental plantings which will tend to require more water. Private areas on the other hand may have different types of plantings that require less water and include hardscape elements such as decks that use no water.
You may have a theme in mind for your design. Xeriscape principles can be applied to any design theme. Xeriscape designs simply incorporate water usage foresight into the end result.
Xeriscape landscape design adds one unique step to the traditional design process. That is the identification of water use zones. Typically a Xeriscape design will include three water use zones:
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Sample water zone diagram Larger on next page |
This is actually a design step. You need to group plantings into water use areas but they should fit into your planned use areas. Understanding your site and your goals will allow you to create water use zones that will be invaluable in helping you choose plantings that fit your theme and work well in your landscape environment. This will also help you pick plantings that establish the form and texture of your space as well as define it. This is also part of the Plant Selection principle.
Soil Analysis & Improvement
Soil analysis includes both a physical examination of the soil as well as a chemical analysis.
The physical examination will determine what type of soil you are dealing with. There is a wide range of soil from sandy to silt to clay. The texture and composition of the soil impacts drainage. Soil texture is typically plotted across a triangle that measues the proportions of sand, silt, and clay. This determines the soil texture.
The type of soil may vary within a single landscape so your analysis should consider any different areas you are working in. Poor soil structures may need to be improved. Clay soils that do not drain well may be cultivated or may be amended by adding good soil to it. Soils that are dry may benefit from adding organic matter. This should be mixed into the soil as a whole and not on a spot basis.
Having a chemical analysis of the soils in your landscape will tell you if you need to amend the soil with lime or fertilizer and how much is needed. You can usually get a free soil analysis from your local county extension services. You can also purchase soil test kits.
Adding organic matter to individual planting holes for trees and shrubs is not recommended. The use of organic matter may make drainage worse and may actually encourage root systems to stay in the original planting hole rather than expand outward. Making a larger planting hole that is at least two times bigger than the root ball will provide a better alternative in allowing root systems to expand. Larger root systems allow the plants to absorb water more readily.
The purpose of soil analysis is to create soil that is ideal for plants to expand their root systems. Ideal soil has good aeration and drainage but still holds adequate moisture and nutrients needed for root growth. Your moisture requirements will be determined from the water use zones you determined during the Planning & Design principle. The principles are all interrelated. You created water use zones during the Planning & Design principle and now you have determined through Soil Analysis & Improvement what you need to do to create ideal soil conditions. You are now ready to consider Plant Selection.
Plant Selection
Your goal is obviously to select plants that are compatible with your design. However, you also need to select plants that are going to be compatible with the site and environment. This means you need plants that match the available moisture and light. They should also be able to adapt within the local fluctuations in temperature and moisture. It is a common misconception about Xeriscape designs that they use plants that are drought tolerant. That is an important consideration but not the only one. A plant’s ability to survive periods of heavy moisture if necessary may also be a selection criteria.
In addition to the considerations of the planting site environment you may also want to consider other factors:
What is the plants size and form going to be when it is mature? Will it overgrow the site or crowd out other plants? Will it’s mature size maintain the proper scale in the design?
What is the plant’s growth rate? Will it require a lot of maintenance to keep it pruned and nicely formed?
What is the plant’s appearance? What is the leaf texture and how does it fit in with other plants? What are the plant’s colors and do they mix well with other adjacent plants or landscape elements? Does the plant have seasonal colors?
Does the plant serve the correct functional purpose? Does it serve as a screen or provide ground cover? Is it the correct form and size for the specific planting site?
It is important to remember that one of the key elements of the initial Planning & Desgin was the creation of water use zones. You want to select plants that are also appropriate for each of your zones. This may seem like a lot to consider and it may seem very constraining. Many plants and grasses can survive without supplement water once they are established. The key is group your plants according to their water needs and then match those to your site conditions and design.
The Use of Turf principle is your next big consideration. This should have been considered during the initial Planning & Design in terms of what areas need to be turf to meet the design requirements and to meet the use requirements.
Efficient Irrigation
By establishing water use zones we are trying to minimize the amount of supplemental water required for irrigation. Irrigation may be a necessity but it should be applied in the most efficient and effective manner to make sure that maximum benefit is received from the minimal amount applied.
Since we have established water use zones it only makes sense to establish irrigation zones that match. Irrigation is applied just enough for the needs of the plants in each zone. The water requirements within a zone may vary depending upon the type of planting. For example, new plants will need more supplemental water while that are getting established.
The method of applying the supplemental water will vary also. Since plants in low or moderate water use zones do not need water on a regular basis, temporary watering systems such as hoses or watering cans may be used. High use areas may warrant the installation of a permanent system. All permanent systems need to be well designed to evenly distribute water in the correct area and they should have automatic controls. Whenever possible efficient watering systems such as drip irrigation should be used.
Whatever water is applied to the landscape, whether it be from natural rainfall or from irrigation, it should be retained in the soil for as long as possible in order to maximize the benefit. This is accomplished through the Use of Mulches principle.
Use of Mulches
Mulching is often considered to be decorative. In fact it is one of the most beneficial practices in landscaping to conserve moisture. Mulches help reduce evaporation from soil and thus reduce the need for supplemental watering. By slowing down evaporation they also help maintain soil moisture at a even level. This helps roots grow more deeply.
Mulches also serve to insulate plants from heat and cold. They also help control weeds that compete with plants for water and other nutrients. Organic mulches are usually best. The more fine-textured mulches hold moisture better and allow air and water for flow more freely through them.
Different materials can be used for mulches. The wood and other organic mulches allow for oxygen to get to the root system more easily than rock or stone mulches. They will also return some nutrient components back to the soil over time as the break down. Course compost can also be used as a mulch, but be sure to ask for weed-free certified composts.
Rock or stone mulches can also be used selectively. Rock mulch will stay in place more effectively, especially in windy areas. Like any other mulch, it must be selected to the area and its usage.
Mulches must be applied correctly in order to obtain the maximum benefit. Usually 2-3 inches of organic mulch is adequate to hold in moisture. Mulches should be spread outside of the plant canopy to encourage full root expansion. It is usually best to clear away a inch or two of much from the trunk or main stem to prevent wood rot.
Mulches must be maintained also. As the mulch breaks down, is compacted, or is otherwise removed it should be replaced with fresh mulch. This is just one aspect of the Maintenance principle.
Maintenance
The role of maintenance in Xeriscape is to discourage new growth that demands more supplemental water. Your objective is to maintain health plants but you can still do this while controlling growth that will mean higher water requirements.
One of the more basic controls is to reduce the amount of fertilizer applied. This can be done by fertilizing less or fertilizing less often. Another approach is to use fertilizers that are released slowly over time.
Fertilizers should be applied at the appropriate rate. Make sure your application is correct for establishing plants versus established plants.
Another method of controlling growth is to reduce pruning and then to prune lightly. Pruning promotes new growth so by reducing the amount and intensity of pruning you are controlling growth.
Related to this is mowing. Turf should be mowed to the recommended height and only be mowed when approximately one-third of the leaf will be taken off the top. Turn is shaded areas should not be mowed as much as sunny areas. Also, during periods of dry conditions the amount cut off should be reduced. This encourages the turf to root deeper.
Removing weeds is another important maintenance task. Weeds compete with landscape plants for water and other nutrients. By eliminating the weeds you eliminate the competition for the natural resources that are available in the soil. Weeds can be minimized through the Use of Mulches principle. Mulches must be replaced as they break down or wear away over time.
