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Irrigation run time for st.augustine?

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williams lcm

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Discussion starter · #1 ·
I was told 45 minutes min per zone. I was told this deep watering encourage a deep root system. Some sod guy going around my neighborhood says 10 min per zone is enough. What is a good rule of thumb?
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#2 ·
It depends on how much is put out in that time frame and how frequently you run the system.

I know MN is no FL but typically you want long run times once or twice a week equaling 1" of water. My guess would be that further south it'd be like every other day.

I know a lot of FL is Sandy soil so you need to water more often and deep watering isn't as effective since it drains faster.
 
#3 ·
No one can tell you definitively how many minutes to water your lawn without knowing how much water your irrigation puts out and coverage. You're best bet is to run your irrigation for the 45 minutes and have tuna cans spread throughout the zone and measure the water collected. You want to put out 3/4" of water each time you water if you have typical sandy soil. If you have a clay or muck base then you won't require as much water. This time of year, once a week is usually sufficient. I have some customers who water every 10-14 days right now even with the warm weather we've had. You're best bet is to water as needed instead of setting it up for x amount of days per week. The grass will tell you when it needs water. The blades will start to fold in half lengthwise and the color will change from a nice green to a grayish bluish color as it drys out. Every property is different so the guy telling you 10 minutes is enough is not that bright. There's no way to know if 10 minutes is enough without checking your soil and how much your system puts out.
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#4 ·
Drip, spray heads, or rotary heads? What is the temperature? Humidity? Shade? Wind? Soil porosity? What is the evapotranspiration demand for the previous 4 days? Drainage adequate--excessively fast? Does the system have a rain shut-off? Soil moisture level sensors? Is the customer willing to spend plenty on water so as to get excellent quality? Or is slight dryness acceptable? Are there watering restrictions? Are trees, shrubbery and flowers included in the mix along with the St Augi?

I run my rotary heads about 30 minutes per zone, every day. 10 minutes for spray heads. Skip a day or two for a good rain. Skip days during cold weather. We use the percent key if the weather goes over 90 degrees--increase to 125 percent.

However...I have heard that fungus problems can arise on SA when cooler, wetter weather occurs in the fall.
IF THERE ARE POTENTIAL FUNGUS PROBLEMS...cut back to 3 times or 2 times per week, (deeper, but more minutes). The more often the grass leaf blades are wetted--the greater will be your disease problems. To reduce disease--water in the afternoon--making sure that the grass has at least 6 hours of drying time before nightfall.

Check the output per zone and per minute by placing coffee mugs under the sprinklers.
 
#5 ·
RigglePLC said:
Drip, spray heads, or rotary heads? What is the temperature? Humidity? Shade? Wind? Soil porosity? What is the evapotranspiration demand for the previous 4 days? Drainage adequate--excessively fast? Does the system have a rain shut-off? Soil moisture level sensors? Is the customer willing to spend plenty on water so as to get excellent quality? Or is slight dryness acceptable? Are there watering restrictions? Are trees, shrubbery and flowers included in the mix along with the St Augi?

I run my rotary heads about 30 minutes per zone, every day. 10 minutes for spray heads. Skip a day or two for a good rain. Skip days during cold weather. We use the percent key if the weather goes over 90 degrees--increase to 125 percent.

However...I have heard that fungus problems can arise on SA when cooler, wetter weather occurs in the fall.
IF THERE ARE POTENTIAL FUNGUS PROBLEMS...cut back to 3 times or 2 times per week, (deeper, but more minutes). The more often the grass leaf blades are wetted--the greater will be your disease problems. To reduce disease--water in the afternoon--making sure that the grass has at least 6 hours of drying time before nightfall.

Check the output per zone and per minute by placing coffee mugs under the sprinklers.
Click to expand...
Not trying to step on your toes but if you water St Augustine grass 3 times a week or even twice right now, you'll have brown patch fungus bad. You shouldn't even have to water it that much in 90 degree weather. Increasing time won't do any good, you'll just have wasted water running off or puddling up and evaporating.
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#6 ·
^this too. You'll be farming mushrooms. Fungus is an issue. We may have cool evenings but we're still hitting 80 in afternoon.

You gotta take into consideration our soil structure too. Little OM and calcareous sand that drains well. Plus our water tables which fluctuate all over even an individual yard.
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#7 ·
Nunyabisnes said:
Not trying to step on your toes but if you water St Augustine grass 3 times a week or even twice right now, you'll have brown patch fungus bad. You shouldn't even have to water it that much in 90 degree weather. Increasing time won't do any good, you'll just have wasted water running off or puddling up and evaporating.
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Click to expand...
Your not stepping on his toes, he's not from Florida. He really does not know, just like I would not know how to water in Michigan.
easy-lift guy
 
#12 ·
a general guidleine that I give. 20 to 30 minutes on pop ups. 45 to hour on rotor zones. Mixed head zone fix it. Twice a week until we fall back, then once a week until we spring forward. Lawns with extreme exposures like dense shade, climate we are currently facing may all change those but those are pretty solid guidlines IMHO.
 
#13 ·
Any suggestion I make on irrigation is based on an estimate of how much water the grass is losing per week vs how much nature is supplying. Soil type also plays a role in this estimate. So does grass type.

I like that one. Mixed zone fix it. First thing I do when asked to maintain a lawn is fire each zone on the irrigation system. Red flags are mixed heads. Bigger red flag is gear drive heads. I have yet to find a system using gear drive heads that are correctly spaced and nozzled. I buy a lot of 4" pop up bodies for short grass and 6" for St Augustine, as well as MP Rotator nozzles to install in them. The craziest thing I can think of to use in St Augustine is the open case impact sprinklers such as the Rainbird Maxipaw heads. The nozzle only sticks up about 2" above the lip of the case. Don't want to install the case high because the mower will destroy the head. The body and nozzle combination I like in St Augustine is the Hunter 6" pop up and MP Rotator nozzle. Run time on those under conditions of total water loss per week and no replacement by rain looks like a total of 2.5 hours per week. Clay soil can be irrigated twice a week totaling that 2.5 hour run time. In sand, I do not believe in very extended intervals. Sand cannot hold that much water. Excessive watering just leaches whatever herbicides or fertilizers were applied down to the water table. I will actually water grass under conditions of no rain and high ET losses every day on sand. Conversely, I do not like to put small amounts of water often on clay. That just keeps the surface wet and causes weeds to grow.
 
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