Tom Ingram Ask a Master Gardener
‘AAt this point in the summer, I try not to ruin myself by watering my lawn and landscape. What can I do to minimize my water consumption? —BF
Water use is usually not one of the first things we think about when planning our landscaping or selecting our plants, but next to plants, water will probably be our second. largest expense for the lawn during the year. So, let’s talk about some ways to conserve water on those brutally hot summer days.
First, know your water needs. As for grass, it’s pretty simple. During the summer, Bermuda grass needs about an inch of water per week and fescue needs about 2 inches. If you water your lawn with a sprinkler system, chances are you’re overwatering. Why? Because it’s hard to guess how much water your sprinkler system is applying to your garden. To be sure, you’ll need to do something we call an ‘irrigation audit’.
Irrigation auditing is a fancy term for determining how much water your sprinkler system puts into your garden. To perform an irrigation audit, you will need something to measure the water delivered to your lawn by your sprinkler. There are official water irrigation measuring cups for this task, but you could also use something like a tuna can. You’ll need more than one, so just make sure all of your water-catching containers are the same so your results are consistent.
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Once you have the water catchment containers, scatter them in a single sprinkler area, turn on your sprinkler system in that area for about 20 minutes, and wait. After the 20 minute cycle is complete, gather your containers and measure the water in each. Hopefully they will all hold about the same amount of water.
Now we have to do some calculations. Let’s say that after 20 minutes, your containers held an average of about half an inch of water. So if you have a lawn in Bermuda that needs about an inch of water per week, you know you’ll need to water that area for about 40 minutes to meet its needs. If you have a fescue lawn, you’ll need to double that, or about an hour and 20 minutes per week in that area. At this point, you can either assume that all zones are delivering water at approximately the same rate, or repeat the same process for all of your watering zones. The second option will be the most accurate.
Now that you know how long your sprinkler should run, it’s time to program the sprinkler controller. Watering best practices tell us that it is better to water less often and more deeply. Here’s why.
Deep watering encourages plant roots to grow to reach the water. By doing this, your plants will become hardier during the summer as they will have a stronger root system that is able to reach water deeper in the ground. When we water more frequently, we encourage the plant’s roots to stay closer to the surface where they will be more sensitive to changes in water levels. And plants with roots near the surface will need to be watered more often.
Another point to remember here is that if you want to conserve water in your lawn, plant a lawn grass that requires less water, such as Bermuda grass or buffalo grass. Fescue is a cool-season grass that will do well in the summer if (and that’s a big if) you’re willing to provide it with the water it needs to survive.
An additional strategy is to add a sensor that will turn off the sprinkler system when it rains. Plus, there are several sprinkler controllers that have technology that checks the weather online to see if you need to water, or they give you access from an app on your phone to turn the sprinkler off. remotely, in case of surprise rain when you are away from home.
There is a growing trend in landscaping that encourages homeowners to move from a grass lawn to a more “natural” landscape made of native flowers and grasses. There are several advantages to this strategy. Low water usage is a side benefit since native plants have learned to adapt to our climate and because of this they generally have lower water requirements. These plants have been hardened to survive our Oklahoma summers…much like those of us who have lived here our entire lives versus visitors from a more temperate climate.
For those of us who remember when it used to rain… rain barrels are a great way to supplement your garden’s water needs. The city of Tulsa usually holds a rain barrel sale every year, or you can find them locally or online. Rain barrels help capture and reuse rain that falls on your roof. Once you’ve made the initial investment in equipment, you’ll have a convenient water supply nearby for years to come.
For more information on water conservation and low-water plants, see the Hot Topics section of our website, tulsamastergardeners.org. See you soon in the garden.
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You can get all your gardening questions answered by calling the Tulsa Master Gardeners Helpline at 918-746-3701, visiting our Diagnostic Center at 4116 E. 15th St., or sending us a email to [email protected]