Flex Daily watering way too infrequently

My Flex Daily is watering way too infrequently. I’ve been setting-up and tweaking my Rachio for two months now and I’m at my “wit’s end”. In short I evolved from manual to Flex Daily schedules and tuned the parameters using the best advice from:

How to setup a Flex Daily Schedule
How do I calculate my precipitation rate
Drip emitter calculator for precipitatin rate
California Crop and Soil Evapotranspiration

and I’m confident that the output per run is correct (tested empirically by putting my drip lines in a bucket and measuring the output) yet the frequency of runs is way too infrequent. As an example from one zone, based on ~6 years of gardening experience and a soil moisture meter, irrigation should be running about every 3-4 days, yet the Flex Daily schedule wants to run every 20 days. This is obviously a huge disparity.

Nevertheless, I decided to trust the Rachio and went on vacation because I figured that I’m only gone for 10 days, it’s September, and most of my landscaping is either mature or semi-drought-tolerant, so how bad can it be? Well, I came back and my lemon tree is dead, so needless to say my wife and I are pretty upset and she’s yelling at me to “fix it” but I’m out of time to tinker on my own and could really use some help.

Diving through the discussions it seems that increasing the crop coefficient is the suggested way to increase watering frequency; however, manual crop coefficient calculation from the last above link suggests a value of 0.30 for immature citrus in my location yet the default for the zone was 0.75, so something just seems wrong. What should I do? I’m thinking despite confidence in my soil type setting to lower Available Water, but perhaps that will just shorten the watering duration that I already worked so hard to get right?

So going back to the point that I’m out of time to tinker on my own because things are dying, I’m looking for a multiplier to a parameter that will simply get the watering frequency in-line with my expectations for this time of year as a better starting point and to stop my landscaping from dying, and then I can refine the settings over time.

Any advice appreciated. Thanks!

@mfuller I think there are a few things at play here. The first is I typically recommend starting with one or two zones in flex daily, get those dialed in and then roll out to other zones as your confidence in the programming increases. It’s definitely a different way of watering than what most customers are used to. In your case it seems like you are using flex daily on a lot of different crop types than just grass (e.g. trees, shrubs, etc.) IMHO these are sometimes harder to dial in since the default values we use are harder to validate since there are so many varieties versus just cool or warm season grass which are usually spot on.

For your 20 day watering on your tree this is due to our default root zone depth of 24 inches (2 feet!). All types of trees have different root zone depths and this goes back to understanding the type of tree and how deep the roots go. The easy fix here would be to move that value down to something like 9 inches which would have your frequency increase. After changing an advanced zone value you can immediately look at the soil moisture graph and see what the simulated watering will be for the next two weeks. One other thing to note is if you decrease root zone you will water more frequently but your durations will be much less.

Now I know @Kubisuro is one of our tree masters so maybe he can help with some adjustments.

I do appreciate you as a customer and hopefully we can get that system dialed in. Hope this helps.


I use mature tree crop evapotranspiration since I have mature and immature trees on the same drip. I do adjust the emitter rate based on the tree (canopy) size. Citrus does not seem to mind “wet feet” as much as, say, stone fruit (which I found out the hard way recently with root rotted plum --whoops–and manifested visibly while I was away on a business trip… it may survive after reducing the emitter to 0.5gph from 1gph).

I like @franz’s suggestion of using a shallower root depth, perhaps a few inches past the current root depth, to encourage deeper root growth. Shallower depth will rapidly increase frequency. Adjust to a deeper root depth and assess emitter rates annually based on canopy size/tree response. 24" may be too much for a recently planted tree. Hand supplemental watering of the immature trees may be necessary if you have mature trees mixed in with immature trees.

Anyway, I think we’ve both learned to closely monitor our trees :slight_smile:

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Thanks, I’ve divided the Root Depth by 4 to increase the frequency and divided the Nozzle Inches-per-Hour by 4 to preserve the run time. I guess part of my original question was if these parameters are linear in their effects, which seems to be the case.

Another part was if there is a better way to “lie” to the Rachio to get the desired results. E.g., it’d be a much simpler user interface if I could input how often and how long I think it should run per-zone under current conditions and it adjusted from there for seasons and weather instead of reverse-engineering lies upon lies of parameters, or if it had a single “multiplier” like the “seasonal adjustment” setting on manual controllers.

Maybe Fixed or Flex Monthly is supposed to do this, but it appears to me that the Rachio still tries to track soil moisture based on its perceptions of water delivered and what happens to it over time, so if its beliefs are wrong, then everything is still wrong. E.g., when I was on a Fixed schedule I was getting “saturation skips”, and I figured if I have to sort-out the various parameters I might as well go full Flex.

@Kubisuro thanks. FWIW my understanding on citrus is that they are sensitive to overwatering, too (and I lost one newly-planted tree this summer for that reason). Recommendations I’ve seen are to water deeply once/week in summer, but for younger trees in my climate (90-100 degrees in the summer and low humidity). I’ve had both 2x and 3x/week work, though at 3x you really have to watch soil moisture carefully. The problem with citrus is, once they show signs of distress it may be too late. With underwatering you can add water and maybe it will recover (we’ll see what my lemon tree does), but with overwatering the excess moisture lingers and the roots may drown before it dries-out.


Good to know. I almost lost an avocado this year with overwatering too. It’s flourishing now with half the water. Many lessons I’ve learned.

For summer, that’s roughly what Rachio schedules at 24” root depth, .13 AWC and 0.75 crop coefficient. The interval is lengthening as fall set in. I’m mainly adjusting emitters to reach desired soil moisture. Thus not ideal that I’ve got mixed tree ages on single zones.

Yikes. I’d hope to see at least some signs of distress before that downhill!

Best of luck with the lemon tree.

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