Senior Horticulturist, Fort Worth Botanic Garden
Don’t go with the flow of many homeowners in your neighborhood who try to make a splash by using entirely too much water in the landscape. Rather, tap into current thinking about wise use of this precious resource and become a wellspring of information that you can leak to your friends and neighbors. Let’s take a look at eleven easy tips anyone can absorb for saving water in the landscape.
The first thing a good steward of landscape water should do is determine what level of irrigation, if any, the landscape will need. Try to use a majority of plants that won’t even need irrigation after establishment. However, if your landscape will feature plants that have different water needs, group the plants according to their water needs: very low water (no irrigation after establishment), low water, medium, or high water use. Place high water-use plants, such as annuals, in one area so it’s easier to water them. Since annuals are short-lived, most don’t have a chance to develop extensive root systems that will store a lot of water, so they need frequent watering. Moisture-retaining polymers can be incorporated into the soil where annuals are planted. These polymers absorb and retain moisture that benefits such small plants as annuals. These same polymers don’t work for larger plants because their roots quickly outgrow the area with the polymers.
A critical tip for retaining soil moisture in Texas is to mulch beds after planting them. A two-to-three-inch covering of the soil with organic mulch such as shredded hardwood mulch greatly retards the loss of moisture from the soil through evaporation. Furthermore, mulch inhibits weed growth, stabilizes the soil temperature, and adds organic matter to the soil as it breaks down. When applying mulch to beds, avoid piling it up around stems of plants because the mulch can rot the stems. When applying mulch around trees, pull the mulch two to three inches away from the trunks. Pine bark is a popular mulch in most of Texas, but it can easily wash away during a heavy rain. Shredded hardwood and cypress mulch stay in place much better.
One of the best ways to reduce water consumption in the landscape is to reduce areas of grass. Lawn grasses use more water than any other plant in the landscape. Furthermore, an extensive lawn is nothing but a monoculture that contributes little diversity to the plant palette. Replace areas of grass with beds of groundcovers, shrubs, and/or perennials that provide more visual interest and consume considerably less water.
Next, water plants only when they are thirsty! Don’t set the irrigation system on automatic; rather, run the irrigation only when plants need to be watered. Most plants show they need water by wilting or turning a pale, grayish-green color. Or, push your finger into the soil to see if it feels dry. Buy a rain gauge to measure how much rain falls on your garden. Install a rain sensor on your sprinkler system. These sensors keep the system from operating while it’s raining. Soil moisture sensors measure the moisture content of the soil and turn on your sprinklers only when the soil is dry.
Create shade in your landscape. Shady areas can be twenty degrees cooler than sunny spots, and plants need much less water in shade than in sun.
If you install an irrigation system in your beds, install one that uses water efficiently. Overhead sprinkler irrigation is the least efficient because so much of the water is lost to wind and evaporation. Drip irrigation, on the other hand, places water right where the plants need it: on the root zone. Drip systems use 20 to 70 percent less water than overhead irrigation systems.
Conserve water by planting in fall rather than in spring. Fall is the best time of the year to plant trees, shrubs, and perennials in Texas because the plants have a chance to establish their root systems for several months before the onslaught of summer’s heat. Plants planted in the fall also take advantage of fall rains and cooler temperatures and therefore experience less evapotranspiration.
Space plants appropriately according to their mature size to reduce competition for water. Overcrowding increases the need for water in a particular area. It also increases the insect and disease pressure in that area.
Collect rainwater from your roof. Rather than let this water run off your property and into storm sewers, capture it with a rain barrel and use it to irrigate your beds and containers. Many different sizes and shapes of rain barrels are on the market now.
Finally, fertilize correctly. Use slow-release fertilizers that send nutrients slowly to the plant roots rather than fertilizers that release all their nutrients quickly and cause growth spurts in plants. Over fertilization causes plants to get sick or to grow too fast. In both cases, plants use more water than they need.
Now that you’ve absorbed all this information about water conservation, put it into practice and let it have a trickle-down effect on others in your neighborhood!
This article is adapted from Steve’s book, Easy Gardens for North Central Texas, published by Color Garden Publishing.
Posted June 6, 2014
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