Are frequent short waterings ok?

Hi - new user here. Love it so far!

Does anyone know if frequent short waterings are ok? I’ve always heard infrequent (2-3 days a week) but deep waterings are the best for root systems. I live in Florida right by the coast and have probably the sandiest soil possible. I started customizing the Advanced Settings with what I know and now my Flex Daily is running very short times at very high frequencies. For example, my fixed nozzle zones are running for 5 minutes at a time on a daily basis. My rotor zones are running for 12 minutes at a time on a daily basis.

It feels like I should be running longer watering times every 3-4 days but since my soil is so sandy who knows?? I looked at NRCS website and my AWC is .04. I have almost all St. Augustine grass which has an average root depth of 6 inches. Any insight? Thank you!!

It is certainly best to water only 2-3 times per week, but with sandy soil (which has limited moisture capacity) and hot weather (Florida, duh), you will probably end up watering almost every day. Not best for the grass, but about all you can do with sand.

Using your AWC of 0.04 and 6" deep, with say 50% allowed depletion, Rachio calculates your soil can only hold 0.04 x 6 x 0.50 = 0.12" of water at a time. So even watering every day only gives you 0.84" of water, which won’t be enough in Florida in the summer (might be okay now). Sand is a bummer.

You might get by watering twice a day, allowing quite a bit of time between, to water less days. But I’m not sure.

Thank you this is really helpful. You’re not kidding; water just goes straight through here. I’ve drained hundreds of gallons from my pool at a time and the dark spot at the end of the hose never got bigger than a foot or two. It’s nice being able to walk to the beach though and we’re on a well so calculating the cost of irrigation is a little different.

Am I correct then that Rachio is setting it’s watering times to deliver 0.12"? So a five minute run from my fixed nozzles (at the default flow rate) is delivering that amount of water? I ordered measuring cups to get the precise delivery amount. I was going to do the math myself to determine run times but I’m guessing that’s what Rachio is doing for me?

Well, I calculated the 0.12" based on the AWC of 0.04", root depth of 6" and Allowed Depletion of 50%. Multiplying those gives 0.12", so that would /normally/ be what Rachio would do with Flex Daily (not as sure with other schedules).

Maybe. Probably. 0.12" in 5 minutes is 1.44" per hour Nozzle Flow in/hr. If that’s what your nozzles actually put out on your zone, then yes, although that’s with 100% efficiency (you didn’t mention your efficiency).

Good to confirm flow with measuring cups. You can also run the zone for a given number of minutes and measure the area of it in square feet, to calculate Nozzle Flow as:

Nozzle in/hr = Gallons_Of_Water_Used / Minutes_Run / Area_Sq_Ft * 96.25.

BTW, many sites refer to the Nozzle in/hr as Precipitation Rate, which I think is much better, but within Rachio it’s Nozzle in/hr. The reason I think it’s better is that Nozzle in/hr has nothing to do with actual nozzle flow, but is the average flow for all the nozzles over the zone.

I know this was a while ago but just wanted to say thank you! I measured the precipitation rates of all my zones and got everything dialed in nicely. It’s still running short watering times almost every day but your explanation makes a lot of sense and the lawn is starting to come back nicely. Appreciate the time and help - thank you!!!

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