Lawn turning brown


I think that there are assumptions buried in some of your statements that do not match Rachio’s algorithm. I would recommend a) moving all but one of your zones to a fixed schedule. This will allow you to dial in one zone while the other zones are getting watered the way you want. b) Change parameters on the flex daily zone then go into your soil moisture graph and flip to the right to see how your changes affect the watering schedule. This will allow you to get a “feel” for the evapotranspiration curve and what effects will come from your changes.


It only knows if you don’t change the zone watering duration in the schedule.

At this point, your probably tired of going back and forth on the issue (I know I am). Just tell me what settings to put in there so it will water my brown grass, but not for 16 hours and not water if there’s an inch of rain forecast for tomorrow.


Thanks for the reply, my town only lets my side of the street water on Sunday, Wednesday, and Friday due to the summer water ban.


I would start with one zone first with daily flex schedule For a few weeks and put the others zones on a fixed schedule. And if you like the results of flex daily apply it to the rest. I also have cool season grass and I had to make some changes i start with one zone and the zone run for 3 hours including cycle and soak which it make it seem is running for ever but it’s not because there is cycle and soak in between now the one the I started on a flex daily is really healthy and I will be applying it to the rest of my zones .


Pains me to say this but the Flex method is not very compatible with three watering days a week. I’d go to fixed, watering as you’re used to,during the summer ban and use flex the other parts of the year. This is still taking full advantage of the controller :slight_smile:


I agree.

But I still think it is a bug in their software. If I specify that the Nozzle Inches Per Hour is 0.25”, the system shouldn’t say that 0.6” of water was added to the soil when the zone only ran for an hour!

Having to tweak Available Water and Root Depth then checking the Soil Moisture graph forecast graph until I see a reasonable outcome is bogus.


If my wife saw a zone running for 3 hours, she’d rip the controller of the wall in the garage and drive over it in her SUV.


We’ll see who gets there first. Your available water is 0.2 (in/in). Your root depth is 6 in. Your MAD is 50%. .2 * 6 = 1.2 * .5 = 0.6 is the size of your “gas tank” (before the warning light comes on).

On another note, 0.25 in/hr is a really low flow for a sprinkler. What are your sprinkler heads, and how did you calculate flow rate?

Edit: I did not see the “zone only ran for an hour.” That part does not sound right unless the zone received additional water.


What type of sprinkler do you have and, and/or what nozzle?


Great explanation of where the 0.6 comes from!

I took my flow rate in GPM * 60 minutes to get gallons per hour, then converted gallons to cubic feet, then divided by 5000 square feet in the zone to get the depth of water over the area. But in the past I put an empty tuna fish can out in the grass and measured how much water was in it after the zone ran for an hour. I have since become a vegan so don’t have any empty tuna cans to validate the number but recall there was about 1/4 of an inch of water.


I have Hunter rotor heads typically with 1.5 GPM for the 90* sweep heads, 2.5 GPM for the 180* sweep, and 4.0 GPM for a head that sweeps 360*.


Rotors like this

Rotors like this




These are nozzle type for the series on the 1.5 I would start with 0.60/ 0.69 precip in/hr start with one zone first for a few weeks and if the grass is happy apply it to rest. leave the other zones on a fixed schedule !



After a happy hour beer and a motorcycle ride home to think about this I don’t actually know if flex daily would really ever work with your watering restrictions. It would water Wednesday and then could probably make it to one of the other days but would usually water only two days a week. With your restrictions and only three days allowed I’d say a fixed schedule with Weather intelligence features turned on is your best bet to avoid browning but also benefit from any precipitation events.



I have a very long thread around flex and altering the durations. I’m not a fan of how it is working but I’m pretty sure this could fix your problem.

First, make sure your available water capacity is in fact .2 ( I just looked at middlesex and without a precise location, I can’t tell exactly, but .2 might be too high). If it is not, adjust and delete your flex schedule the recreate it. That will readjust their schedule coefficient.

The duration times in that schedule is what is required based on the data to fill the soil column with water. If you lower those durations the flex will assume that based on that new runtime, you will fill your soil column with water.

Again, not a fan but I ran into this issue by lowering my duration in an attempt to get Mother Nature to cap off the soil column (causing flex to run shorter so that flex would want to run more frequently) and my yard got hot.

You really need to catch cup your zone. Head placement has a big effect on your pr. I have 4 turf zones with the same heads in all, one of my zones has 2x the pr than 2 of my other zones, so they have to run much longer.

Ugh, I just saw this, and I think you are right, unless flex can run on any day, he will just continue to fall behind each day it can’t run, ultimately leading to drought, yuk.


allthough dry weather can cause your grass to turn brown, colder weather than the grass is used to, can too. Not sure if that is in play, but it could play a factor.


I had similar problems on top of a $300 watering bill and a brown lawn. The only way to get my Gen2 to work is just dumb it down and use what features you can and wing it. I can’t use a rain station unless I get my own. These days any station further than several hundred yards is of no help. It could rain there everyday for a week and 90° at my location. So no watering a dying lawn. Oh, and I hate the new app. And . . .

I could go on but the damage is done. There’s a lot that is not implied and a lot implied that these controller just can do, but . . . in order to get it all set up the way they need it, you have to be a Botanist and bit County Extension Agent.


I am on a three day flex and zones often skip one or two cycles so I’m unclear why the three day flex shouldn’t work. If it was watering on every schedule day and still could but deliver enough, I’d understand.

However my lawn is stressed a bit from the California heat too lol. I did a catch test and adjusted to 1". I also reduced to allowed depletion to 40% allow my lawn to adapt to the deep water and soak cycles. We’ll see.


Are these gear drive rotors? Their application rate is .50 to .60 inch per hour. Rachio’s default of 1 inch per hour for rotors is completely wrong. I have mentioned this repeatedly. Rachio you need to look at the specification catalogs for Hunter, Rain Bird and Toro and make this correction with your default values.