Watering in Winter in the South

I live in central South Carolina and have Centipede grass, which requires more water than normal in summer, and has shallow (6") roots, but which turns brown and goes dormant in the winter. It’s starting to turn now (we had a 31 degree night time temperature last night).

It is normally accepted by homeowners here (not landscapers or horticulturalists, but homeowners) that no irrigation is necessary in the winter. Grass is supposed to be tan/brown anyhow, right? Plus, SC usually gets a good amount of precipitation in the winter. But I’m reading some sources that indicate that during dry periods, even in winter, it is best to irrigate some. Well, the last rain we had was 5 days ago, there’s no rain forecast for 6 days, and not much then.

So, should I water? I use Flex Daily and like it, but can’t imagine putting down almost a half inch of water at once like I do in the summer. I was considering reducing my root depth to result in less water, maybe to half or even a fourth of it’s normal value. But with the ET running about .05 to .06, a fourth would water every other day, and that really seems like too much/often. People are going to think I’m crazy. I’ve also considered halving my Crop Coefficient so as only to require half the water. I don’t know. Right now I’m watering everything with 0.1" water manually because my graph says it’s down to 17%.

For those living in similar climates with grass that goes dormant, do you water during winter? What are your thoughts? IF I’m going to water at all, I like the idea of letting Rachio handle it; just not sure what to change for this non-standard applications.

We have similar problems in the summer with California Native plants and those from other mediterranean climates. They like water in the winter and a little in the summer. I would like the ability to set a once monthly setting so I could give it a deep or light soak once a month in the summer and also if it doesn’t rain in So. Cal. in the winter.

I have found that if you start adjusting all of the settings you loose the value of the controller which is to irrigate based on the plant and weather conditions. When you do that, you really don’t know which setting needs to be adjusted next. It turns into, as another in the community said, “A Hot Mess.” One of my designer friends will not recommend the Rachio for that reason.

I WISH- They could just add a Non-Traditional schedule setting to the Advanced Menu and add a Monthly setting to the frequency.

Now, you & I have to remember to do a manual irrigation. I’m old and so is my memory.

Here in NC, our backflow prevention valves are above ground. Not worth keeping things hooked up and risk burst pipes for us here.

While there are a lot of settings, just two can be adjusted to change what Rachio does any way you want: Root Depth will change how much water is applied at one time (so if I put in 3" it will water half as much as my standard 6"), and Crop Coefficient, which changes how much water over time is applied. Here, my lawn requires 0.85, so halving it would apply half the normally “needed” water. Those two settings would be easy enough to change, and then to change back. I just don’t know how much I should really change it. Or IF I should even try.

FYI, I decided to change my settings as follows, and for now, continue through the winter using Flex Daily:

  • Lawn root depth was changed from 6" to 2.5", resulting in 40% of the amount of water being applied during one day.
  • Crop Coefficient was changed from 85% to 50%, resulting in 59% of the water being applied per week than it normally would apply.
  • Similar changes to the drip zone.
  • Since this obviously takes a lot less time, I’ve moved my start time from 5AM to 8AM.

All these are based on a SWAG (Scientific WAG). For now, I just like the idea of applying SOME water during the winter, as we’ve had 80 degree Christmas days here, but realize that dormant grass requires much less water over time and at once. Most sources agree that in South Carolina, some irrigation should be applied during spells of warmer and dryer temperature, and this should provide for that automatically. This will also insure that shrubs and trees have some water during a time when I normally wouldn’t have watered them. Of course, if it’s too cold, the system will skip watering with the Freeze Skip. I’ll have to see how much this will cost me, but don’t think it will be too much. At this point, no watering is scheduled until December 9.

To document these changes, as well as to remind me to turn them back to more reasonable values, I’ve set up a Calendar task/message outlining the changes made as well as stating to turn them back, for March 15 of next year (about when we should start watering normally again).