So, unlike this time last year, my Flex Daily schedule for my Bermuda grass is now watering every two days instead of 4, IIRC. I haven’t changed any settings that I can remember. I live in Phoenix, btw.
I have two zones for the lawn, and it’s watering each zone for about 48 minutes (not including the soak time) every two days. It’s been in the mid to high 90’s here. My sprinkler heads put down .62 inches per hour, so that’s a half inch every two days, averaging out to 1.8 inches per week? That seems like a lot of water, plus why so often? I’ve got root depth set to 8". And soil set to loam. I’m a bit torn on that since I’ve seen many posts saying we have sandy loam here in north phoenix but many saying we have clay loam here in the valley. So, I thought I’d compromise.
EDIT: I just changed it to clay loam and it changed to every 3 days. One of these days I’ll have time to do the jar test to see what I really have. I’m at about 32nd Street and Cactus if anyone lives around here and already knows. TIA.
Ok, I realized I could do this empirically. I took about 7 soil depth readings and it was a consistent average of about 7" (meaning, not much variation). Maybe I’m saying that incorrectly. I’m saying the probe moved fairly easily then just stops at about 7". FWIW, the back yard had been nothing but dirt since about 2010 until last April when we installed this sprinkler system and BOB Sod (short for Bank One Ballpark sod, it’s named this because it’s used for the Diamondbacks baseball team).
Since I’ve had the root depth set to 8" for awhile AND it just watered this morning, I’m going to conclude it is indeed NOT loam (which is what is was set to for the last few weeks) and instead I have clay loam. I’ll try to remember to update this thread in a few weeks and see if the root depth increases. I do have cycle and soak set, to 15 min water, 30 minutes off. With 2 zones this works well with only 15 minutes per cycle of no watering happening in either zone.
I picked a random address near 32nd and Catcus, and the web soil survey shows that the native being versions of what I believe to be sandy loam.
But, you have to always ask yourself, how much non-native soil, or how much was ground turned over when the land prep for your development, or even the soil added with your BOB sod?
That being said, it looks like you also have the brand new feature enabled, which makes the crop coefficient a dynamic setting that adjusts throughout the year. This is a pretty ideal concept, but being brand new, we are all curious to see how it performs. This could explain why you feel it is watering more frequently this year…
Thanks. I’ll say this, before the sod was put down, I spent at least two full days tilling about 2,000 sq ft. The first day, I didn’t realize the dirt was so hard I’d need to soak the crap out of the it first, and the tilling was miserable. Like tilling concrete. I then cycle and soaked the yard for a week and the tilling was a bit easier. I did till to about 8 to 10" and the soil below that was insanely hard. Caliche like?
Maybe I’m mistaken, but I’m fairly confident of the reasoning I used above to determine that since I had been watering for a long time with a root depth set to 8" and it not being that deep, the watering time needs to be increased per cycle which is what’s needed by clay loam vs loam.
Being in the vicinity of the mountain preserve there, it is possible you might have some caliche, but usually I think it is found deeper than 8-10". I suppose if you found that hard pack, assuming a clay loam isn’t really going to hurt things at the end of the day.
Stalking your thread as I’m in Tempe and designing my Irrigation upgrade right now.
I did the Soil Jar Test and found that I actually have Silty Loam (not what I expected). It does get hard as a rock when dry, but main issue is lack of organic matter.
It sounds like Rachio’s “algorithms” don’t quite hit the spot for us here in Phoenix. Ideally I would like soil moisture probes in front (1 zone) and back turf (3 zones) zones. My citrus, succulents (cacti/agave/aloe) are easy enough since I deep water only occasionally through drip or drip into watering spikes (citrus, trees).
Here are a couple of resources that might help if you haven’t already found them.
Have you guys tried soil moisture probes connected to the S1/S2 inputs?
Seems most people setup to essentially over water and let the soil moisture probe skip waterings. Sounds like it would work but not as “smart” as I was hoping.
Not sure I completely agree with this. I’ve been using Rachio flex daily exclusively for nearly 6 years with great results, as have a number of other members on the site. The only thing that was “lacking” was the variable crop coefficients, so I would adjust manually a couple times a year (winter/summer). The average crop coefficients in Rachio did seem to underwater slightly in the summer, and slightly overwater in the winter. With the new dynamic crop coefficients, I’m hoping that variable is removed. Still watching it closely to see how it adjusts heading into the summer months.
Thanks Troy for the clarification and excellent description. I’ll spend some time coming up to speed on it.
Still would prefer the Closed-loop Soil Moisture Sensor if that’s possible to get working.
Cheers, Tom
Apparently, unlike the order that Rachio lists them in the app, Clay Loam has the highest AWC. I can’t imagine that’s right considering many people here in the valley say we have sandy loam, which has an AWC of 0.12. But what throws me off is I’ve had the roots depth set to 8" for a long time and I couldn’t once get a probe down that far. Doesn’t that suggest I need longer watering times? Not shorter?
Bless it, so I changed it to Sandy Loam and now it’s back to every two days, for 52 minutes per zone, which is about 0.5 inches. This is absurd. I’m just going go disable this and do about .6 inches every 3 days and see how it goes.
Rotary nozzle. MP Rotator heads. I did that test (whatever it’s called) and got the efficiency as well as average PR of 0.62" per hour. (there’s a bit of overlap with in all zones so that’s why the net output is higher than the rated 0.5" per hour as spec’d).
I wonder if what’s changed this is them switching to dynamic crop coefficient? I think bermuda is typically about 0.65, it’s at .72 now (dynamic). Since this type of bermuda is supposed to need less water than common bermuda, I think the Crop Coefficient for this grass should be quite a bit lower. Maybe 0.62? Maybe that would push it back to every 3 days?
It honestly depends on where you are in the valley. I’m probably the one posting that, I’ve made a comment similar to this on the pages, only because I grew up in the farmlands of Chandler always hearing that we had “clay soils”, so I just assumed everything was a clay or clay loam. But there are a number of areas near South Mountain, San Tan Mountain, Camelback, etc. that are sandy loam. It really just depends on your proximity to a mountain from what I’ve seen. I’d say that a vast majority of the valley is clay loam though. At my house in Gilbert, the WSS shows me with “Trix Clay Loam”, if I go a few miles south on the map (towards San Tan Mountain), it quickly changes to various types of Sandy Loam.
If you want to DM me your crossroads, I can help you pinpoint your soil via the WSS website.
Interesting about the proximity to mountains. I’m at about 25th Street and Aster, 85032. We’re less than a mile from the south side of a preserve with a small mountain peak, Shadow Mountain. TIA!
Here is what the WSS is showing…I did a area of interest of about 1/2 mile around the intersection provided.
Down to about 24" (which only your biggest trees would be beyond this), this is the description of what “Estrella Loam” is…I’m honestly not sure whether to classify you as sandy loam, or just loam, but for sure, I think it is clear that you are not in a clay loam area…
A and C horizons
Hue: 10YR, 7.5YR
Value: 5, 6, or 7 dry, 3, 4, or 5 moist
Chroma: 2, 3, 4, or 6, dry or moist
Texture: Loam, silt loam, very fine sandy loam (less than 18 percent clay); some pedons have .5 to 1 inch thick strata of finer or coarser material.
Well drained; slow runoff; moderate permeability in the A and C horizons
