LSU AgCenter Horticulturist
(07/10/20) Water is our most precious natural resource. According to the American Water Works Association Research Foundation, on average, Americans use 29 billion gallons of water per day, with 30% or 8.5 billion gallons per day being used for gardening and lawn care. With two-thirds of the world’s population projected to face water scarcity by 2025, according to the United Nations, it’s time to plan for shortages.
As a homeowner, you can make water-wise landscaping decisions. It doesn’t mean that your lawn cannot be attractive. You can create a functional, easily maintained landscape by following a few guidelines to help conserve water. It will save money on your water bill and help you cut back on the need for irrigation.
The EPA recommends these key tips for water-smart landscaping:
— Plan before you plant.
— Make water-wise plant selections.
— Go easy on the turf.
— Water wisely. The timing matters.
— Use automatic irrigation that is efficient and well designed, and work with irrigation professionals.
— Use mulches to conserve moisture.
— Harvest rainwater.
Planning before you plant is the first essential step when making water-wise landscape decisions. Did you know that plants help conserve water and improve water quality by slowing and collecting rainwater?
Plants prevent soil from eroding into our waterways; they lessen impacts of flood damage and serve as natural filters to protect our streams, rivers and lakes. Trees alone can capture up to 50% of rainfall, thereby reducing stormwater runoff.
Select the right plant for the right place. Perhaps the most important step in making water-wise landscaping decisions is selecting plants based on your regional conditions. Take into account the annual rainfall and average temperatures for your area. To plan for minimum irrigation, choose plants that are adapted to low-water environments, such as native plants.
On average, Louisiana has 88% daytime humidity and 60 inches of rain per year, with average low temperatures of 56 degrees and average highs of 77 degrees. We average 81 days above 90 degrees and only 20 days below 32 degrees. Be sure to also consider microclimate conditions, soil type, existing topography and intended use of the space, then group your plants based on their water needs.
In my opinion, shopping for plants is the most exciting part of the process. Remember — right plant, right place. Work with local nurseries and cooperative extension agents to help guide you to appropriate plant selections for your location.
For the most water conservation, go easy on the turfgrass by limiting or eliminating grassy areas in your landscape. This will not only conserve water, but it will also conserve time and money spent on maintaining grass and cut back on watering and mowing tasks — a bonus. Keep in mind that some grasses, such as centipede and zoysia, are more drought tolerant than others. St. Augustine, Bermuda and carpet grass require more water.
Group plants with similar water needs. This helps create “hydrozones” and reduces water use according to each zone — for example, turf versus bedding plants versus shrubs and trees. Turf and bedding plants will require the most water, whereas well-established shrubs and trees with extensive and deep root systems require less.
Water wisely. Automatic irrigation systems can be a real time saver. They also can help you get a little extra shuteye because the best time to water plants is early in the morning between 2 and 8 a.m.
Watering during the heat of the day reduces the efficiency because more water is lost to evaporation. You can water in the evening between 6 p.m. and midnight, but this can encourage fungal diseases when plants remain wet for extended periods.
Schedule irrigation according to each hydrozone, for particular plant needs and in response to decreased rainfall. In addition to conserving water, adequate irrigation is more effective and efficient, encouraging deeper root growth and creating healthier plants that are more drought tolerant.
It is important to work with irrigation specialists when designing, installing and scheduling irrigation systems. A properly designed irrigation system will conserve water while an improperly designed and scheduled system will waste water and money.
Use mulch. Mulch covers the soil, conserving water by preventing evaporation and preserving water at the root mass while providing a source of organic matter to landscape beds. Mulch can also help prevent compaction and provide weed control. It’s also attractive.
Finally, harvest rainwater. Rainfall is free and frequent in Louisiana. Our average annual rainfall of 60 inches provides ample opportunity to harvest rain. Use rainfall harvesting equipment such as barrels and cisterns to help supplement your irrigation program. Many local nurseries, co-ops, tractor supply stores, large box stores and online retailers carry them.
Do your part to help conserve water for future generations by following these water-wise guidelines. Consult LSU AgCenter publication No. 3062, “Introduction to Landscape Irrigation in Louisiana,” at https://bit.ly/LaIrrigation for more tips.
Group plants according to water needs. Photo by Heather Kirk-Ballard/LSU AgCenter
Water early in the morning between 2 and 8 a.m. Photo by Heather Kirk-Ballard/LSU AgCenter
A rain barrel can collect rainfall so you don’t have irrigate your landscape with household water. Photo by aqua.mech licensed under CC BY 2.0.