Put Your Landscape On a Water Diet

Brad Wier

If you’re starting up irrigation for the year, now is a good time to make sure you’re not needlessly adding water weight to your plants.

The approach of warm dry weather can invite worries about slimming down for summer. I’m talking about your water use, of course — and your outdoor landscape. If you’re starting up irrigation for the year, now is a good time to make sure you’re not needlessly adding water weight to your plants.

Think about it. What in your landscape most needs weekly watering to stay looking healthy? You probably already know the answer, and it’s not the trees, shrubs, native perennials, cactus or mulched shade garden. It’s usually just the lawn, and often only the lawn in full sun! That’s why most modern irrigation systems are hydrozoned — to water grass separate from landscape plants, so plants with similar water needs can be watered together or not at all.

Water-smart landscapes in south-central Texas are already loaded with tough watersaver plants. But if you’re running the entire irrigation system once-a-week, they’re all being watered on the same interval, defeating the purpose of using hardy plants in the first place. If you see xeriscapes getting hit with irrigation all summer long, it’s worse than junk food: it encourages them to put on tender extra growth at a time of year when they’d be better off getting by on their own.

A few savvy gardeners have adopted an ingenious workaround: they keep only the grass on weekly watering and leave the xeriscape beds either on a separate biweekly schedule or run the system manually in summer as needed. It’s one of the fastest ways to drastically decrease the water used for irrigation.

Examples of plants that can get by without scheduled irrigation include established shrubs, trees, perennials, yuccas and everything included on our WaterSaver Coupon list. Many of them are loaded with flowers and color all season long. Overwatering these plants all summer long leaves them more — not less — vulnerable to August conditions.

The sample watering schedule from Tucson, Arizona below demonstrates this method. If the irrigation is hydrozoned, irrigation can be reduced from once a week to once or twice a month.

Plant Types

Weeks between watering, in summer

Trees 1-3
Shrubs 1-3
Cacti & Succulents 2-4
Vines & Groundcovers 1-3
Annuals 1
Warm Season Turfgrass 1

Careful scheduling can really slim down your landscape’s irrigation bill and put water where it’s needed most — and it’s why many WaterSaver programs focus on ways to decrease the grass area. As a bonus, the savings can be used on summer vacations instead!

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