Double check my drip configuration


We were using the default emitter nozzle for our trees until today. It was running that cycle for 3.5 hours, every 5-6 days it seemed. I went out in the yard today and noticed it to be very wet so I contacted Rachio.

They pointed me at a spreadsheet,

For each of my trees, I have 2, 2.0GPH emitters so it’s telling me my nozzle rate should be 6.4167.

After changing it, my trees are now set to water for roughly 25 minutes. Does that sound right? I was watering them for about 2 hours, every few days before rachio. So I’m trying to get a good idea if I was overwatering before, or now I’m under watering?

I’d be hesitant of those numbers. I lost a plant and almost lost a whole fence line of shrubs with high numbers like that. If you care to go down the rabbit hole

Hi, again!

I see you are using 2GPH emitters too and you changed yours from 3.2 to 0.9. Since I have two per tree, do you think it’s safe to put them at 1.8? With 1.8, it says it will water for 1 hour, 16 minutes.

Do you only have trees on that zone? My problem that I have is that my yard was built having both trees and shrubs on the same line.

Only trees on that zone.

If you haven’t, check out the link below to see some of the concepts of watering our plants/trees.

And then use @azdavidr’s spreedsheet which is how I decided on my drips.

My drip system is on such autopilot since I used these numbers, I don’t even think about it. I just make sure there are enough drips for each plant as they grow.


That seems like a ridiculously high number. I believe it uses the assumption of (area=1) in the PR calculation, which I have long argued is wrong for the type of drip systems that we have. That’s why I made the calculator that @Modawg2k refers to. Purely for a reference point for you, I have three 2 GPH emitters per tree for my trees, and my PR is 0.4 in/hr. I’d encourage you to go through the calculator to see what PR it recommends. It would be great if you could share your calculated PR and watering duration.


Love seeing AZ people on here! They can relate to our crazy temps.

I’m super new at all of this, so I’ll start reading and hopefully figure out what I need. In the mean time, I removed my custom nozzle so I don’t kill the trees.



So, I put

GPH per plant: 4
Gallons you want to apply to each plant: 5 (They are brand new trees, still pretty small)
Inches of water applied in Flex daily schedule: 2.13
Total plants: 13

It came up with 1.70 custom nozzle type, which waters for 1 hour, 20 minutes.


Well, 4GPH * 1.33 hours = 5.3 gallons. According to the Water-Use-It-Wisely site 5.3 gallons corresponds to about a 2-foot canopy tree. Since you said they’re new it sure seems like a reasonable starting point to me.

The question I have is how long have you had them planted and what was your watering interval and duration before? It’s important not to drastically change things immediately.

Also, be sure to continue updating this frequently as the tree grows. You’ll want to move to the right on the chart above. You’ll need to increase the root depth in the app., find the new ‘inches of water applied’, and calculate a new PR from the calculator. I have some fairly well established trees and am putting down closer to 27 gallons vs. your 5, but probably not as frequently.

Interesting, if I were to water for 27 gallons, it would take 7 hours, 5 minutes. My trees were flooding at 3.5 hours.

You might have harder soil than I do @optize. As your tree grows, it might be better for you to switch to 1 GPH heads and put down more of them per tree. There’s also a chance that they are putting down more than 2 GPH. You can try measuring their output to see if that’s the case. If so, I know that there are pressure regulated emitter heads that folks around here have used.

FYI, my watering time is around 4.5 hours, but I have 3 emitters per tree. That will factor in too as you’ll want to spread apart your existing heads as your tree canopy grows, and add more heads. As an example, when your trees get a bit bigger and you add a 3rd emitter, you’ll be putting out about 8 gallons instead of 5.3 without changing the duration at all. Since you’ll have spread the emitters further apart I doubt you’d have any flooding, but you’ve delivered more water. Does this make sense ?

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