Cracking the Code on Mobile Irrigation Devices

If your sprinklers have one of those fancy new smart Wi-Fi controllers, this tip is for you! Even the “smartest” controller relies on settings that were chosen the day it was installed. Do you know what they are and what they mean?

Cooler weather and rain means your yard’s water needs have dropped considerably. But your so-called “smart” sprinklers seem to be ramping up the watering now — coming on every three days. What happened?

Like most every issue with sprinklers that isn’t a leak, it usually comes down to (yawn) programming. If your sprinkler controller is one of the new smart Wi-Fi controllers, this tip is for you! Even the “smartest” sprinkler controller relies on settings that were selected the day it was installed. And they’re only as smart as whichever buttons were pushed.

And here’s one you may have missed, especially if you’re using a smart mobile controller like Rachio, RainMachine or Skydrop: Warm season grass or cool season grass?

On Rachio, this appears under “zone type,” i.e, “what am I watering?” This is one of those seemingly fun selections under “edit” on each sprinkler section — the same place where you input photos of your yard and name your different lawn areas. There are various helpful suggestions for zone type: Garden and xeriscape are available, along with the classics including shrubs, perennials and even trees. But the one many people get totally wrong is the type of grass, which apparently comes in two flavors, warm season and cool season.

But “season” does not refer to the temperature outside, rather it means the type of grass. In San Antonio, summer temperatures from 80 to 95 degrees require us to use warm season grasses like Bermuda, zoysia and St. Augustine. When the temperature drops in autumn, these grasses stop growing and go dormant.

Any turf specialist would be cringing already, because with the exception of winter rye, “cool season grasses” like Kentucky bluegrass and fescue aren’t grown in San Antonio. Ever. That’s because they grow when high temperatures are between 60-75 degrees. When does this ever happen in San Antonio? (FYI, in winter.) In warm weather, cool season grasses here would, well, die.

According to one Wi-Fi sprinkler manufacturer, at least 30 percent of customers in San Antonio have their grass type set to “cool” season. If that’s true, their sprinklers will be starting to water in earnest now when the summer grass is going dormant. All that’s growing in winter is weeds!

So if you’re hoping to save on water and weeds this winter, check your grass type. If you’re growing zoysia, Bermuda or St. Augustine, your grass is a warm season grass and doesn’t need supplemental water right now.

You’re welcome.

Picture of Brad Wier
Brad Wier
Brad Wier is a SAWS conservation planner. Years in South Texas landscaping and public horticulture gave him a lasting enthusiasm for native plants that don’t die when sprinklers -- and gardeners -- break down. He’d rather save time and water for kayaking and tubing. He is a former kilt model, and hears hummingbirds.
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