Runs drips in evening or morning?

I know grass should be at sunrise, but curious to hear thoughts on when to water shrubs/trees? After a few really hot days, some of my shrubs are looking pretty sad… should they have to wait until morning or should the drips run at sunset to help them out?

Both. I start in the early morning, but my controller has to run nearly all day anyway in these 110+ temps. I have a lot of zones and 1 GPH drips so each zone takes its time. It would probably help a lot with evaporation loss if I could run multiple drip zones simultaneously. Hopefully that will be a new feature in the future.

@Modawg2k, the recommendation to water before sunrise is to lessen the evaporation of water from sprinklers due to sun and wind.

With temps like we’ve experienced the last few days, some plants may need that extra watering in the afternoon.

Flex daily works well for our St. Augustine lawn, but zones that have plants with shallow roots or are not desert plants may need an afternoon watering.

I have an additional fixed schedule that runs a drip zone at 4 each afternoon for some of my flowers and hanging baskets. Without that, those plants would soon turn crispy.

I also have a fixed drip schedule for the late afternoon for the veggie garden. Once the temps cool down (you know–around mid-October :wink: ) those afternoon schedules are not needed.


Like @ldslaron, my 1GPH shrub drips run for 7 hours, so they start at 5:30 and run just past noon. So far my shrubs are looking great through this transition to summer. For my garden I added supplemental watering late afternoon when I was keeping it going at this time last summer, just like @sunny taught me. Like her I also add a second cycle to my pots late afternoon. All but one of my pots are concrete and they become Easy-Bake ovens this time of year.


Ahhh, the Arizona summer heat!:sweat: Just out of curiosity, @azdavidr, are those shrubs on fixed or flex schedule?

My trees, shrubs and lawn are on Flex. Pots and garden are on Fixed. I watered my shrubs once (twice max) during each of the months of December and January, thanks to some rain and a much lower ET. These days it’s firing more like every 4-5 days.

BTW, my potted plants are the biggest challenge these days. Getting enough water without drainage issues is a challenge for me. Pots where the irrigation lines were a bit higher in the run would stop dripping soon after the valve closed, but those down the line would drip slowly all day until the pressure in the line dropped. I just installed a valve at the end of the line that closes when the line is pressurized and drains the line shortly after the valve turns off. It seems to be helping.


Thanks for posting that @azdavidr. I was just curious how you were dealing with these scorching temps. Great to hear that those shrubs are looking good. Hopefully we’ll soon cool down!


I have only two zones, the front yard and back yard, both of which are drips. Front yard is mostly desert landscaping bushes and trees, and the back is a mix of shrubs and trees that aren’t desert landscaping. I have the zones set up on a flex daily schedule which runs every 3-4 days for 95 minutes per zone. The front yard looks fine but my backyard plants look like they’re struggling a bit in the heat - crunch brown leaves on a few of the plants. I live in Vegas which is only a few degrees cooler than Phoenix right now. Perhaps I’ll set up a daily late evening 18 minute watering for the backyard every day and see if that helps them out!

@MisterWil, how many GPH do you put out for the backyard ? I’m delivering about 7.5 gallons per shrub. At 95 minutes it looks like you’re well below that for 1 GPH heads, but maybe you have something higher ?

Given the suggestion from @sunny re the potted plants, I wonder if we could suggest to Rachio that flex water more than once per day given a lower AD value. Effectively it seems like what you’re doing manually, right?

This has come up a couple of times that I can recall. Once was with a garden discussion and another in sandy, coastal types of environments. The short story is that they’re aware of the once-per-day limitation creating problems for some, but the change is a significant one to their algorithms. They’re currently re-working their software so maybe we’ll see it down the line.

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I’ll be honest: I’m not sure - I haven’t measured. I’m using the default Emitter. I should probably figure that out as it appears the default is 1.5gph and that is probably .5 too high?

Curious as what you mean by a 1.5gph default? The nozzle/emitter defaults in Rachio are specified in “in/hr”.

If you’re interested in looking a bit deeper into what is recommended here in Phoenix, and how those recommendations can be made to work with Rachio Flex, take a look at this post. If nothing else, download the spreadsheet and look at the ‘Water-Use-It-Wisely’ information. My concern is that for shrubs you should actually be watering more deeply than you are now, rather than multiple times a day. Adding a second watering my not save your shrubs. Again, the ‘Water-Use-It-Wisely’ is pretty easy to understand and an easy to understand resource.

Ah, hmm, yeah, I only quickly glanced at the default value and didn’t realize that the unit was in/hr. Oops!

I’ll spend some time this weekend looking at those resources and hopefully adjust things a bit better. I don’t think you included a link to the specific post you mentioned?

Oops, I forgot to paste in the link. I corrected the post but here it is as well. I would think it would work well for Vegas too. Keep in mind that if you are watering much more frequently than what’s recommended you might need to make a gradual adjustments over a period of time, just so your plants have time to adjust.

So here are two in question, one is a mexican bird of paradise, and the others are orange jubilees. Not sure of their desert hardiness, but I don’t think they are getting enough water.

Current settings: Each plant has one 2 GPH emitter, Rachio runs for 1h2m with a nozzle of 0.70 in/hr.

Rerunning numbers: Each plant has one 2GPH, but using the 3’ canopy for these, I get 0.17 in/hr. 2’ canopy will produce 0.34.

0.17 in/hr gives a run time of 4h
0.34 in/hr gives a run time of 2h.

I think i’m going to bump the nozzle to 0.34 in/hr to see what happens. I worry that 2gph may start to cause overflow, which I’ve noticed before with long run times.

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Seems like a good plan @Modawg2k. The nice thing about those 2GPH heads is that they create a wider displacement, but like you said you’re more likely to get runoff in areas like that. If it does end up being a problem you can change them to 1GPH and run the zone for longer, or take the step of adding a second 1GPH line to each shrub to get back up to 2GPH but coming out of 2 spots.

That’s cool. I haven’t had my Rachio too long so am not always aware of what’s been discussed. Thanks for filling me in on the history.

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Of course! There are so many great threads and associated conclusions on this forum that some of the issues and resolutions get a bit buried.

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