Sprinkler system timing (lawns, irrigation, landscaping, grow)

[CptnRn]

I'm looking for ideas on how to reduce our landscape irrigation water usage, while keeping the plants and lawn alive in the heat in Austin, TX

QUESTION: I read someplace that soil can absorb water better if you set two different watering times, say one at 5 AM and one at 6 AM. This reduces the amount lost to water running off of the soil. So I am currently doing this, but I'm wondering if it doesn't also increase the amount lost to evaporation. My lawn has no areas that run off onto pavement so all of the water is staying on the landscaping. Am I better off with one long watering period rather then two?

[no kudzu]

I frankly don't see the difference. you should have it set for at least 30-45 minutes anyway. only 15 minutes between waterinfg would not make much difference. frankly I would set them for 4 a.m. that way nobody will have reduced service cause who is taking shower at 4 a.m. you always want to water really early in the a.m. and never let your lawn go to bed wet. too many diseases set in. too many folks think 6.p.m or after dark is ok (but maybe they are trying to not be caught watering) this does alot of harm wirth so much humidty borne damage. 4 a.m will give plenty of time to soak in before sunrise and very little evaporation too. try that...hope this helps...rememberr light waterings do alot of harm =the roots grow up to meet the water and then dry out when there is none. if you water long and deep then roots grow long and deep.

[CptnRn]

While I appreciate your providing a response..., 30-45 minutes!!

That is a little hard to reconcile. I'm trying to conserve water here in AUSTIN, TX where the heat and evaporation rate already result in high water losses for landscape irrigation. The soil here is also just a little bit of top soil over caliche and limestone.

In the spring of 2008, after having a City water conservation audit performed on my sprinkler system I turned the watering time way down (6, 8 & 12 minutes, 2 times each week) as recommended by the auditor, planning on increasing it as needed, my gut feeling told me it was too low.

After 4 weeks I was getting burned patches and I started turning it up. By the end of summer my lawn had 4 dead patches and it no longer looked healthy. I clearly didn't turn it up fast enough. I have been nursing it back to health since then and its looking pretty good now, but my watering times have increased to this:

Watering twice a week:
12 minutes for shrub zones with spray heads (24 min./wk)
12-14 minutes for St. Augustine lawn zones with spray heads (24-28 min./wk)
16 minutes for St. Augustine lawn zones with rotary heads (32 min./wk)

2 adults living in a 2400 SF house with 3600 SF of landscaped area my water use last year was as follows:

Jan____Feb_____March____April____May ____June___July_____ August_____Sept____Oct_____Nov_____Dec
7300__9400____12400____17600___13300__18500___2060 0____18800_____24600___23600___22300___11400

So at its peak, the water use for landscaping was 17,300 gal/month, or 4,325 gal/week. For a 3600 SF yard, that is 1.2 gal/SF.
At 1 US gallon = 231 cubic inches, that is 277.2 cubic inches of water per SF. Or 1.92 inches of water over the entire landscaped area.

Most of the recommendations I have seen for watering lawns recommends only 1/2" to 3/4" of water for lawns. I'm already watering more then twice that amount during the hottest month. I know I'm loosing a lot due to high temperatures and the evaporation rate during hot summer months. So I'm looking for anyway I can to water more effectively.

[no kudzu]

obviously theconservation audit guy was not a gardener. Do you see that by watering only once a week at the time period I suggested you are still very close to my original suggestion of 30-45 minutes each week? I certainly was not suggesting doing that much twice a week. Again a good soaking watering only once a week beats two for shorter times. I'm sorry if I was not clear. Try earlier in the morning only once a week and hope for rain.

[Shagbark Hickory]

If you have clay soil and it goes a while without any rain or irrigation, it is recommened to water a little first to get the soil receptive. Otherwise it will run off. If you don't have clay soil then I wouldn't worry about that. I don't see why it would evaporate any faster or slower by watering an hour later.

[CptnRn]

Originally Posted by no kudzu

obviously theconservation audit guy was not a gardener. Do you see that by watering only once a week at the time period I suggested you are still very close to my original suggestion of 30-45 minutes each week? I certainly was not suggesting doing that much twice a week. Again a good soaking watering only once a week beats two for shorter times. I'm sorry if I was not clear. Try earlier in the morning only once a week and hope for rain.

Thanks, I will give it a try. It does make sense that a deeper watering should soak in more. I used to water only once every 5 days, but the city changed its requirements last year and only allows me to water on Wed or Saturday.

@ Shagbark, not much clay soil on this West side of town, but the East side of town has some of the most expansive blackland prarie clay soil to be found anywhere.

[FLPL75]

CptnRn
You can calibrate your irrigation system to see how long it takes to get the 1/2 to 3/4" amount of water by following the steps in this link
Calibrate Irrigation (http://santarosa.ifas.ufl.edu/Portal/module%204%20fertilize/Calibrate.html - broken link)
According to our extension office 1/2 to 3/4 " twice a week is all you need to keep your lawn looking good
We also have St. Augustine grass here in FL. In our county they just went to twice a week watering restrictions based on addresses.

Deeper watering will encourage a deeper root system. Also if you cut your grass using the highest setting on your mower during the really hot season this will help to retain the moisture

Also keep in mind if your woody ornamental (bushes) are established they only need to be watered every 10 days if you have not received rain. So if your bushes are on a separate zone you can manually control when these get watered.

Here is another link that has some good information on Lawns
The Lawn (http://santarosa.ifas.ufl.edu/Portal/module%204%20fertilize/turf4.html - broken link)