More Granular Crop Coefficient Settings

REQUEST: Enable a table for users to enter crop coefficents as monthly values and have the program grab the Kc for the current month from said table.

Rachio currently auto-adjusts on a magical basis I’m not looking up right now. :wink:. It also defaults to a Crop Coefficient (Kc) of 80 at my location (California central valley south). The result for my Fescue is a superb winter lawn and a stressed summer lawn. Like maybe no-one-else I am a lazy guy, so I’ll put a lot of effort into something once hoping to never touch it again.

Enter UC’s Kc data set: University of California Turfgrass Kc

If the user is sufficiently inclined to use the “Advanced” settings and willing to go to the effort, allowing them to use this table to guide the Rachio could be a real help.

For example, my Rachio has been adjusting for climate, advising me, etc. But I see my turf is stressed. Hmm? Checking out the Kc table I see my turf, transitioning out of winter cold toward summer heat, actually needs a Kc significantly higher then .80 to keep it happy in April, then in May, even though the weather is warmer, the turf has adjusted to it’s environment and the Kc can drop back some.

Now being the “lazy guy” mentioned above, I’d really rather not have to remember to make these changes to my Rachio programming every month to keep my turf really happy, but using an annual average just doesn’t cut it at 110°F.

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I’ve set reminders to adjust my Kc for fruit trees and lawn. But yes, having some way to adjust the Kc automatically would be pretty great. That’s next level advanced stuff right there! The turf webpage has been my go-to as well but usually I’m looking at the minimum Kc for turf that I can get away with hah.

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I like this idea but to be realistic it would take too much engineering time to build this.

We don’t actually adjust anymore (we did this in V2 of the software :wink:) Since V3 those values are static.

I was hoping that we would have baked this back in this year (I definitely see the value of dynamic crop coefficiency(?) ) but our plates are full with other initiatives. At some point I hope to re-implement this and maybe do something simple like a steeped % per month or something similar.

Unfortunately for now if you want higher values in Summer and lower values in Winter it is manual user adjustment.


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You are the hero we don’t deserve. :smile:



It seems a pretty simple table if it remains unused unless the user enters data and activates it. (But that doesn’t mean implementing it is actually simple at all.) Meanwhile, back at the ranch…

I’ve co-opted Kubisuro’s idea and scheduled it into my calendar.

BTW, that v2:v3 drop of functionality you point out might go a long way toward explaining why the efficacy of the Rachio took a nose dive in environments with large climate swings (15°-115°F maximum winter-summer temps) last year. Even though my Rachio was all setup and tweaked “just so”, when v3 came out havoc ensued with my turf. Now it appears the only way to restore the “magic” will be to manually perform the adjustments on a regular basis.

Just what is that Rachio does when it “seasonally adjusts”?


Thanks! I’ve co-opted your idea and scheduled it into my calendar.

— 7

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The Flex Monthly Schedule FAQ appears to say the Kc is “baked-in” using the Flex Monthly schedule.

The Flex Daily FAQ implies it may not be, or perhaps is just different as frequency but not duration changes.

I use Flex Daily. Am I using the wrong Flex-type? Or might I be on the right track with fine-tuning Kc values?

I am sooooo confused!


Flex Daily is our most dynamic schedule. I call it the anti schedule since it doesn’t run until it has to. If your grass is straining a bit in the summer just bump the crop coefficient up 5% or 10%. It only impacts frequency.

Flex monthly is a lot more predictable but only changes once per month so you might not get the full efficiency that Flex Daily can provide.

You could always put some zones on each and do a quick comparison.

Hope this helps.


Can you please do this NOW!!! Please, please, please, please, please, please, please!!!

The old way was purrrrr-fect. This new-fangled way isn’t nearly as good.


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Know your grass genus and species.
If you have a ‘cool season’ grass, it will thrive in your winter and as my botany teacher said, “languish in the summer”. You will have to water even more in the summer so set your specs for the hottest month in the warm season.

The reverse is true for warm season grasses.