Years ago I went to an irrigation seminar hosted by the City of Mesa (Arizona). Based on my sprinkler type (rainbird pop up spray) they recommended a water time of 20-25 minutes three days per week in the summer.
Using Rachio defaults and Daily Flex it’s giving me a water time of about 38 minutes per station and about 2 or 3 days per week.
I have hybrid bermuda sod. What are others seeing for their water duration and frequency in the summer in the Phoenix area?
Should I leave it at 38 minutes (seems too long to me)?
Suggested settings for Daily Flex in Phoenix to get me started? At least something to start with and I can fine tune later.
It depends whether you use HE-VAN, VAN, U Series or Traditional MPR spray nozzles and the distance.
I use the HE-VANs that I installed last September.
I’ve noticed a large decrease in my water bill from switching to HE-VAN nozzles from the VAN nozzles and my October and November water bills were the lowest ever. I didn’t even get Rachio until early December 2020.
My nozzles are the HE-VAN 10, 12, and 15. The Precipitation rate is in 1.58"-2.24" on the extreme ends for my set up, with the vast majority within 1.72-1.99" per hour.
I have a turf-type tall fescue and hybrid bluegrass lawn.
I use Fixed Schedule for the lawn, as I change it a lot and know what it needs from previous years before Rachio. I need to dial in the Flex daily settings to match what I know my lawn wants.
My current schedule for June is 3-4 days a week 20-24 minutes per zone. I split it up into 8 minute cycle and soak for 52 minutes. You should be using less minutes per week than me with Bermuda than my cool season lawn.
I use Flex Daily for the my trees, shrubs and large flower pot zones. Flex Daily has saved so much water for the plants on drip.
I recommend the HE-VAN, U Series, R-VAN and MP rotators for pop up heads. I like the relatively high flow rates of the HE-VAN, U Series, and MP800s so all lawn and drip zones can run between 9pm and 7am minimizing evaporation.
Agree with everything @ECOBEARD says. “Spray nozzles” is a bit too vague. There are so many manufactures and models out there with wildly different precipitation rates (inches per hour) that it is hard to say 38 is too long, or too short. The standard setting in Rachio for a spray nozzle is decent, but depending on what you actually have in your yard, could be off by quite a bit. Standard fixed spray nozzles can have a PR from 1.5"/hr to 2.5"/hr, while a VAN (variable arc nozzle) can have PR’s as much as 3.8"/hr or more.
To start, if you can identify your nozzle manufacturer and model, we can use their spec sheets to get closer. If you are interested in investing some time, you can do a catch cup test or a meter read calculation to dial in the nozzle inches per hour setting a bit more.
Unless you need to switch the 12’s out to get better overlap on your zones, I don’t see a reason to otherwise. They have a pretty uniform PR between them based on the spec sheets. If these U-series work out for you, I’d stick with them over an HE-VAN any day. A fixed spray nozzle is going to be more uniform an efficient over a VAN any day.
Rain Bird claims the HE-VAN are high efficiency.
There’s a video on the Home Depot website stating that both the HE-VAN and U Series were tested and both have excellent efficiency and uniformity. Just an FYI.
HE-VAN efficiency is identical to U Series as both are matched precipitation, unlike the traditional VAN nozzles. I reposted my response on my original uncommon lawn post as this will get deleted here shortly
I like having all zones watering all the same day. This is useful for head to head coverage depth in overlapping areas between zones and to not let the pets play on the lawn right after watering. That’s why I have slightly different precip rates so they would water all the same day if I switched to flex daily to account for the shading in some areas. The lawn then dries out all the same time even with different watering times and depths. I wish I could be more help considering different lawn species. I adjust the frequency manually and use a fixed schedule. I have only had Rachio since December and want to switch to flex daily for the lawn, as it’s the last plant type not already on flex daily.
