You can design a landscape that conserves water as well as energy. Here is a brief overview of some water-conserving landscaping strategies.
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. Your particular microclimate will also affect evapotranspiration in different areas of your yard.
It’s best to water or irrigate your plants in the early morning when evaporation rates are low. This also provides plants with water before mid-day when the evaporation rate is the highest.
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:
- Planning and design. Provides direction and guidance, mapping your water and energy conservation strategies, both of which will be dependent upon your regional climate and microclimate.
- Selecting and zoning plants appropriately. Bases your plant selections and locations on those that will flourish in your regional climate and microclimate. Always group plants with similar water needs together.
- Limiting turf areas. Reduces the use of bluegrass turf, which usually requires a lot of supplemental watering. Consider substituting a turf grass that uses less water than bluegrass.
- Improving the soil. Enables soil to better absorb water and to encourage deeper roots.
- Irrigating efficiently. Encourages using the irrigation method that waters plants in each area most efficiently.
- Using mulches. Keeps plant roots cool, minimizes evaporation, prevents soil from crusting, and reduces weed growth.
- Maintaining the landscape. Keeps plants healthy through weeding, pruning, fertilizing, and controlling pests.
Solar heat absorbed through windows and roofs can increase cooling costs, and incorporating shade from landscaping elements can help reduce this solar heat gain. Shading and evapotranspiration (the process by which a plant actively moves and releases water vapor) from trees can reduce surrounding air temperatures as much as 9° F (5°C). Because cool air settles near the ground, air temperatures directly under trees can be as much as 25°F (14°C) cooler than air temperatures above nearby blacktop.
Using shade effectively requires you to know the size, shape, and location of the moving shadow that your shading device casts. Also, homes in cool regions may never overheat and may not require shading. Therefore, you need to know what landscape shade strategies will work best in your regional climate and your microclimate.
Trees are available in the appropriate sizes, densities, and shapes for almost any shade application. To block solar heat in the summer but let much of it in during the winter, use deciduous trees. To provide continuous shade or to block heavy winds, use dense evergreen trees or shrubs.
Deciduous trees with high, spreading crowns (i.e., leaves and branches) can be planted to the south of your home to provide maximum summertime roof shading. Trees with crowns lower to the ground are more appropriate to the west, where shade is needed from lower afternoon sun angles. Trees should not be planted on the southern sides of solar-heated homes in cold climates, because the branches of these deciduous trees will block some winter sun.
Although a slow-growing tree may require many years of growth before it shades your roof, it will generally live longer than a fast-growing tree. Also, because slow-growing trees often have deeper roots and stronger branches, they are less prone to breakage by windstorms or heavy snow loads. Slow-growing trees can also be more drought resistant than fast-growing trees.
Courtesy of Energy.gov