I suppose that depends on how deep the rabbit hole you want to go. The most basic advice would say you're okay to wait a full week as 2" satisfies what you need. If you wanted to really understand your irrigation needs, check out this thread.

ET and irrigation guide

ET and Irrigation Guide Water management on soils keeps evolving as technology allows moisture sensor to help drive the decision on when to soil needs water. But before we had moisture sensors, we used some prediction models to help determine the water needs. Most of the practices come from the...

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I have 419 on some pretty sandy soil. Drainage is very good.

We got about 2” of rain on Monday. How long should I wait before watering again. Normally I water 3 days a week.

You water when the grass shows signs of needing it.

 

I struggle with the answer when the grass needs it. I cannot differentiate what wilting grass looks like.

 

Plan for an inch a week, maybe more during really hot periods.

put on some polarized sunglasses and look at the yard from various points. The darker spots are dry. They won’t reflect the light as well, once you look close you’ll see the wilted and tighter curling of the leaf matter.

 

You'll see certain areas starting to stress out first. Their color will be off. In my yard the stressed area gets a little darker in color and if you get down low and look at the blades you will see them starting to roll up. Some people call it "bluing out" but it doesn't look darker in a good way in my opinion.

 

Also, If you have have good soil and its not too hot, it's best to only water once a week. This encourages the grass to grow deeper roots to find the water.

 

In Texas A&M has an evapotranspiration calculator. It helps you estimate when you need to water. TexasET Network

 

I have 419 on some pretty sandy soil. Drainage is very good.

We got about 2” of rain on Monday. How long should I wait before watering again. Normally I water 3 days a week.

My first question would be, what kind of grass do you have on your lawn? And as for watering 3 days a week, more importantly, how much water are you applying each week? St Augustine needs more water than Bermuda, and being in Florida I'd track how much rain you get weekly and go from there. Use a rain gauge or get on weather underground and find a neighbor with a PWS that measures rainfall and see how much they have gauged. And then late at night go out and talk to your lawn, ask it how he's feeling, ask if he's thirsty, look it over, the grass will tell you when he needs water. LOL!!!

 

+1

Get a rain gauge and and hang it on the fence or somewhere in the lawn that isn't obstructed, it will be money well spent.

Now for talking to your lawn at night, I wouldn't recommend that as you don't want to disturb it while it is sleeping and recovering from the heat of the day and getting ready for the next day But all jokes aside, that is the best advice you can get, know what right looks like so when something is off you can investigate and use some deductive reasoning to figure out the cause. Also, knowing how much water your irrigation puts out over a given time is good to know so you can supplement the rain fall with the correct amount. Sorry, there is no definitive answers as everyone has different soil, grass and micro climates they have to deal with and it's all a learning experience.

 

1 week after rain stops. No need to complicate this one. Resume as usual after 1 week.