An Irrigation Zone w/ Shade & Sun

Hi all,

Last year we bought a new house in Phoenix (Climate Zone 2B, dry / hot). We are in the process of redoing the backyard.

We have a 2 story home that casts quite a bit of shade over the south portion of our lawn. Unfortunately, the sprinkler zones (2) were set up on the east and west.

As you can guess, we have overwatering in the shaded areas and dry spots in the full sun areas. Yikes!

We also have a crabgrass invasion that we plan to remedy by pulling out the existing lawn and replacing with a more shade tolerant St Augustine that only needs 4-5 hours of full summer sun. Our southern portion of the lawn will get this.

Ideally, we know that the sprinkler system should be N/S so we can regulate the zones appropriately, However, bids for the sprinkler redesign are high and it would be great if we could avoid it.

That said, does anyone know of reduced flow sprinkler heads or other solutions that might be a remedy for this problem?

Thanks in advance!

If you are using rotor head, you can change the nozzle so that reduce the pr for some portion. If using fixed spray, change the spray head to different range version,

You can see how PR is changed in here:

@smogowski, I’m not sure what sprinkler head and nozzle type you currently have, but it would be good for you to check out this support article from Hunter on matched precipitation rates. Rotor heads have a lower precipitation rate (PR) by design, but if you have spray heads you can retrofit them with rotary nozzles to reduce the PR.

Hope this helps! Good luck with the crabgrass :crab:

If you’re replacing the lawn anyway, could you take advantage of that and reconfigure the lines so that one zone is in the sun and one in the shade? I’m guessing by your description that you have two parallel lines. If you trenched between them in the middle (or at the sun/shade line) and reconfigured them into two U-shaped lines, you’d have what you need. Does that make sense?

I’m just learning about irrigation… and attended a great class in Gilbert, AZ. You’re in perfect alignment with the very knowledgeable instructor. Modify the sprinkler heads to adjust for varying conditions in a single zone. Good place to start (they can also link you up with great public organizations dedicated to educating the public about AZ landscape and plant care… e.g. xeriscape):