South Gilbert, AZ Initial setup

I just installed my Rachio and have 1 drip zone front and back and 3 grass zones back. I set it to flex daily just for the drips and it is set to water one a week or so for an hour. I havent set up the grass yet because I dont have winter grass planted, will turn on next month when bermuda comes back. Right now I have adjustable emitters on my plants so I havent calculated the gpm or anything.

It seems like the flex daily isnt watering nearly enough. Maybe I have the soil type wrong?
If you are in AZ and have your system set up, what did you adjust or do you run a manual schedule?

Thanks for any suggestions or help.

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There are quite a few of us in Arizona on this forum and are very willing to help. You might want to start with this thread:

@azdavidr has put together a great spreadsheet to get you started.

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The flex daily schedule is the one you want to use. It will monitor the weather and add up the daily water use of the plant material until it gets to the allowed depletion amount and then it starts the watering. You should allow it to happen any day it wants when using this schedule, especially with drip because you aren’t worried about watering on a mow day like you are with grass. For grass you would want to create another flex daily schedule for those zones but then put in the one no water day for the day you normally mow the lawn.

For Gilbert you want to select clay loam as your soil choice. Clay loam has a high water holding capacity so it does go for longer periods in between watering than courser soils like sand.

Selecting the proper root depth will be important too. Normally here we tell people to water shrubs at 18-24" deep. However in watching how the Rachio controller accounts for the water use at that depth it goes for very long times in between watering. I would suggest setting the root depth to around 12" for shrubs and 18" for trees as a starting place. If you had been previously watering very frequently before installing the Rachio you may need to start out at a shallower root depth to begin with and then adjust it deeper incrementally after monitoring how well the plants are doing to make sure they have the roots to take advantage of the deeper less frequent watering. At this time of year for established desert adapted shrubs the recommendation is to water them about once every 21 days. High water use shrubs would be watered a little ore frequently, around once every 14 days.

The first thing I would recommend is changing out the micro bubblers, what you are calling adjustable emitters, to pressure compensating emitters. The micro bubblers can apply the water at very high precipitation rates. With our clay loam soil that is not good because trying to water longer for deep roots causes the water to run off, it will not soak in. The micro bubblers are good to use for flower pots and such which have very loose soils.

The other reason to get away from the micro bubblers is that you don’t know how much water is coming out of each one. This makes calculating a precipitation rate impossible. You will always have more pressure at the first emission point on the zone than you do at the last one. Pressure compensating emitters put out the same amount of water in a wide range of pressures.

As a Gilbert resident you can also contact the water conservation office at and set up an appointment with a conservation specialist that will come to your home and help you with these settings based on your landscape and your irrigation system. The first thing that will be recommended is to install pressure compensating emitters.

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which size pressure compensating emitters should I use? I have established plants bushes and trees.

Do you currently only have 1 emitter going to each shrub or tree? Are both shrubs and trees on the same zone?

Some trees have 3 emitters but trees and shrubs on same zone

It isn’t an exact science, but you will want to figure out what each plants watering needs are, and mix and match drip accordingly. This table from the “Water Use it Wisely” website is like the Holy Bible for us watering here in the desert. You might need to get a mixture of 2gph, 4gph, and 6gph to correctly balance your system with both shrubs and trees being on the same zone.

What I’m not certain of, is whether you should shoot to get the total gallons covered in 1 hour, 2 hours, or more. Typically longer run times with lower gph emitters does better as it gives the water plenty of time to soak in and not pond at the base of the tree/shrub. For reference, my shrub zone runs for 2h 51 minutes, and my tree zones run for 3h 45m. Maybe @robertokc or @Sprinklerman can give their opinions on this…

:+1::+1: for the reference to the holy grail for us desert rats @tmcgahey. Water Use It Wisely has lots of info for Arizona desert landscapes.

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@tmcgahey @azchad
With mixed plants on the same zone, you will have to balance out the best watering time for the trees and shrubs. Troy has given you some good info.

In North Texas, new homes have bubblers on trees most of the time now days. Shrubs are usually on a drip zone with flowers and other plants. We have clay here. A lot of time landscapers dig a huge bowl to plant a tree. It gets bubbled and the bowl fills with water and drowns the tree. Lots of dead trees (I’ve got a soap box to pull out here, but I’ll leave it put away).

If the tree survives for three years, I tell my customers, they no longer need to use the bubblers. More than likely the water is not watering the tree root zone any more. The water from the bubbler at the trunk just hurts the tree in the long run.

Shrubs on the other hand don’t have choice, they get watered a lot. They too, could be turned back to little watering once established, but home owners tend to plant flowers in the beds. So, the shrubs get a lot more water than they need. It’s a constant battle.

Do the trees and shrubs you water now, need water once they are established or will they survive on their own without supplemental water?