Tweak Setup for Las Vegas / Desert Landscape


#1

Spent 2 days reading and reading and trying to understand where I should put my zone settings at and I think it’s time I ask a couple questions.

Landscape type, do I have Shrubs or Xeriscape?
Right now working with front yard zone which is all drip and all established plants like Texas Sage. Still need to figure out what the current emitters GPH is, but I would say each plant has 2 emitters at 1GPH each. Shrubs RZD defaults to 15 inches. Should I leave that?

PR Rate:
Using the calculator spreadsheet seems like I am doing something wrong. 2 GPH per shrub, 8 gallons per shrub, The inches of water from my schedule says .75 in the future. Gives me a nozzle setting of .19, that seems super low. When I change to that I get a run time of 4 hours, which is drastic. Max I have ever run that zone is 60 minutes, but usually I am down in the 30 minute range. The plants are fine, could be healthier in the summer I think so more water is fine. But 4 hours is too much.

Basically I really bought this for these smart features and just to do a fixed schedule was kind of a waste of money. Can someone help me get all these settings corrected?


#2

Las Vegas and Phoenix have very similar growing conditions: very hot and dry summers, mild winters and little rainfall.

What other plants do you have in your xeriscape? Once established, Texas Sage needs little supplemental water. The well-established ones in my front yard do very well with little irrigation. What little rain we do get is usually sufficient, and even though we didn’t have much rain this winter, they bloomed profusely.


#3

Front yard is nasty Rosemary bushes and Tex Sage with 2 trees. Only 1 zone and I cant easily change that. Back yard is Tall Cypress trees in the back and brand new desert plants that were just planted, wife bought them no idea what they are. the Sages are alive and probably need to be pruned, but they never bloom, so I am assuming I am not watering enough.

Should I be changing my landscape type to Xeriscape?


#4

LOL, the “nasty rosemary” is very drought tolerant like the Texas Sage. If over-watered, it will succumb to root rot. These two plants are used in xeriscape because of their drought tolerance.
Can you identify the trees?


#5

Sounds like to me you are suggested a fixed schedule? I really wanted to get all these settings right and let the smart functions work.


#6

A fixed schedule? Nope, not at all.:smiley: To take advantage of all the smart features, a flexible schedule works great with xeriscape and drip. @azdavidr’s handy calculator is a great help to set up schedules. The emitter GPH really needs to be identified.


#7

Would you change any of these settings short of me trying to figure out the emitter GPH?


#8

Here are the plants I can identify:

Front: Texas Sage, Rosemary
Established plants
What should I have Root depth, Crop Coefficient at?
How many Gallons should I assume they want? I have it at 4 right now.

Back Trees: Italian Cyprus, Fan Palm
Established Plants
What should root depth and crop coefficient be at?
How many Gallons should I assume they want? I have it at 4, probably too low.

Looks like all plants and trees have 2-1GPH emitter on them


#9

Well I’m on the verge of returning this.

The smart system does not work very well for Drip. I have no idea whats going on now but my system is set to run every day at this point. I followed the water guidelines and even lowered the gallons required since even the trees are desert adapted, I set up everything based on that drip emitter spreadsheet and my trees were watered for 3 hours last night and are basically watering every other day for 3 hours. there is no way this is right.

Of course I can go in and change some settings to water less, but this is kind of ridiculous at this point. LAs Vegas Water suggests a blanket watering schedule without considering plant types of 60 min for 2GPH and 90 minutes for 1GPH and I think a max of 3 days per week.

Any suggestions before I go hookup the old system and return Rachio?


#10

Post all of your advanced settings and precipitation rate for the tree zone. The 3 hours isn’t out of the question, but there’s another setting you have that is creating the issue you have with frequency.


#11

Here is all data I have:
Las Vegas Desert Landscape and no grass.
Sandy Loam for all Zones
AWC .10 per Soil Website

Tree Zone:
Established Italian Cyprus Trees
1 Brand New Tree
100% Sun Exposure
Root Depth 15 inches
MAD 50%
Efficiency 90%
Crop Coefficient 75%
Nozzle .21

Backyard Plants
All brand new planted last week, all desert plants, a couple grassy things, but mostly shrub type things.
Root Depth 9 inches
MAD 50%
Efficiency 90%
Crop Coefficient 50%
Nozzle .36

Front Yard:
All super established Texas Sage
Root Depth 12 inches
MAD 50%
Crop Coefficient 50%
Nozzle .3

Seems like if I change all zones to Xeriscape instead of Shrubs or Trees, the Crop Coefficients drops to 30%. Basically if the trees get 3 hours of water I would think they should go another 7 days before needing more water.


#12

Forgot to mention that everything has 2 emitters on them and all are 1GPH.


#13

If you walked through the Water-Use-It-Wisely site’s Plant Watering Guide linked to in the drip calculator, you should have seen a table like this.

Note that the root depth for trees is typically 24-36 inches. You have 15" for your root depth, which will cause you to water more frequently. Mine are set to 30" for my established trees. After that tweak your crop coefficient if you don’t like the frequency (higher CC means more frequent watering).

Your watering duration is going to get longer after that change, which you probably won’t like. Two 1GPH heads on established trees is not sufficient, regardless the controller that you use. The goal is to water the periphery of trees and shrubs as uniformly as possible, and you can’t do that with 2 heads. I have three 2 GPH heads on each tree and my trees should probably have more. At minimum use heads with a rate higher than 1GPH so your runtime doesn’t get ridiculously long. For reference my runtime is 5 hours with three 2 GPH heads on each tree, so I deliver 30 gallons per watering about every 9 days. As I type this I think I need to bump up my root depth and deliver more, but right now it’s working for a 3 very well established Ficus trees and a couple of Brazilian Peppers. My 30 gallons are recommended for a tree with a 7ft canopy. Again, this information can be found at the ‘Water-Use-It-Wisely’ site.

For the shrubs follow the same procedure. Go through the Water-Use-It-Wisely site to pick the right root depth and amount of gallons that you should deliver.

Make sure that after you change the root depth and any other settings you run through the drip calculator again! The ‘inches of water’ will change in the Rachio app. and that will change the values that the calculator recomments.


#14

I will go through this again and see what happens. Here is some of my thought process.

The cyprus trees are tall and skinny, so I went with between 5 and 11 gallons for them. But they are probably 20ft tall.

Honestly everything has been living, maybe not thriving, but living just fine with very little water, thats why I was seriously surprised about the watering requirements. I am good with long run times as long as the frequency starts to match the guidelines listed above.

What does Crop Coefficient mean and do? Trees are 75% default.


#15

#16

i think that was the missing link.

I now have the trees getting 12 gallons each watering (once I change the heads) and running about once per week. The shrubs in the front are getting 8 gallons once per week and the newly established plants in the back are getting 3 gallons every 2 days.

Thanks for putting it all together. I will keep on eye on this schedule and see how it goes.


#17

You’re welcome. Definitely keep an eye on it, especially since the desert heat will be intense in no time.