Underwatering?

[snmhanson]

This seems pretty obvious to me but I'll ask it anyway. Most of our grass is yellowing a bit as the heat of the summer starts to take hold. The only places that it are not yellowing are about a 1' radius around the sprinkler heads, under trees that get hit by the water streams and in some areas that get alot of shade. Is this a sure sign that I am not watering enough? If so, how long does it take to see results when you increase the watering? I doubled my watering times about two weeks ago and I can't tell if it is making a difference or not yet. I think it is making a slight difference but should I see big improvements by now. I am now watering twice a week at a little over 1/2" each time. Thanks.

Matt

[sheshovel]

Sounds to me like your useing Rainbirds occilating sprinklers and need to change over to Hunter or ano9ther kind that put out a fine spray.You may be overshooting the grass.

[br1dge]

I would also increase the amount to 1" or more per watering event.

[out4now]

Ground drys from the top down so even though the surface may appear dy it may not be underneath. When in doubt I take a core sample and look at the profile to see how far down it is wet. What type of grass is it? It may need more water depending on variety, also what type of soil is it in? Your local cooperative extension office may have a wesite that you can get with specific water recommendations for the area you live in. From the sound of it though I'm guessing that it is underwatering but it could be something else. In fact this should help if I found the right area : http://gardening.wsu.edu/text/lawns.htm

[snmhanson]

Thanks for all the replies. The lawn is a rye/blue/fescue mix. I actually am using all Hunter I-20 heads so I think I have a good quality sprinkler. I put between 1/2" to 3/4" on the front on Monday and Thursday mornings and the same on the back on Tuesday and Friday mornings but until two weeks ago I was only doing one day a week. I would water a little more if that would help but they recently doubled our water rates here and it is already costing about $400 a month to water our 1/2 acre of grass. We're getting close to the point where it will just make more sense to let it go dormant during the summer then to keep pumping money into it trying to get it to green up. Should I give it a couple more weeks to see what happens, increase my watering times a little or take another course of action? Thanks.

Matt

[Critical Care]

Putting down 1 - 1.5" of water per week is pretty slim for this time of the year without getting additional help from rainfall. I just checked your temperatures on the Web and see them up into the 90's and upper 80's. In these temperatures, like here, you should expect to put down about 2.5" of water. Cost of the water unfortunately doesn't change what the turf needs, alas. Watering two days a week normally would be fine if you were deep watering turf which had good long roots in rich organic matter.

You may want to try .5" every other day, and would probably have to do this for a while until the grass begins to recover, and then begin to back off slightly while keeping an eye on things. Other options... plant more shade trees in key areas, or (not so easy)reconfigure your irrigation zones to water more in the dry open areas and less in the shaded areas. Third option... tap into your neighbors main water line. Good luck.

[snmhanson]

Thanks for all of the replies on this. I have upped my watering amounts considerably and although it is not very apparant yet I think I am starting to see results. How long should it take to see results assuming I am putting enough water on?

Also, on really warm days when the sprinklers aren't set to go off is it beneficial at all to run a short cycle through the system? I am talking about 20-25 minutes per zone on mostly ~1/4" precipitation per hour nozzles and head to head spacing throughout. Does doing this just get the blades and top layer of dirt wet and basically evaporate or does at least some of it make it deeper into the soil? Will it help reduce the stress from the heat or is it a waste? Thanks.

Matt

[Critical Care]

It doesn't take long to brown up a lawn, but turning it back around can be a bit frustrating since it can take quite while.

Since this is your own property, you can monitor the system closely. When temps drop and/or you begin to get rainfall, you'll want to go back to less frequent but deeper watering. Needless to say, you could become a real pro with your controller.

On very hot days, especially with consistant dry wind, you can syringe the turf with a light sprinkling. Though this doesn't replace the normal watering schedule, it does cool the turf down and therefore should help reduce its stress.

By the way, as you know, you can water the living daylights out of some types of soils, such as marine sand, and before you know it its bone dry. There's a lot underground that determines what you results you see above ground. I wonder if you have a soil sampling tool such as the one below? It's a good tool to have to see what's happening down there.

[BryPaulD]

Have you put any fertilizer down??

[snmhanson]

I have put down fertilizer manually and I also have a Fertigator installed which I have been using this year. Incidently, I increased the watering substantially and changed the schedule a little and it really seems to be coming back. I will get a better idea over the next week or two but both my wife and myself agree that there is more green and less yellow now. And for some more good news, I made a mistake on the spreadsheet I was using to figure out my watering costs and they are only going to be about 1/2 of what I thought. So now I am watering away and enjoying some greener grass. Thanks for all of the help.

Matt

[Critical Care]

Ya know, you feel better because that decimal point on your water costs moves to the left on your spreadsheet instead of to the right. In the latter case you'd be screaming and hollering so loud I'd hear you all the way down here. Okay, we got the dry turf figured out, but now for the spreadsheet...

Any problems with the Fertigator?

[Ric]

snmhason

I going to throw some terms at you. Infiltration, Percolation, Hydraulic Conductivity and Field Capacity. These are scientific terms used to measure how water reacts in the soil. With out a soil profile I can not begin to tell you what steps might need to be taken or material applied to increase your Field Capacity. Top dressing might have to be done several times a year until you control this problem, then once a year there after. But I believe the infiltration rate is too high and you have a very small Field capacity. Someone else started to hit on this by suggesting pulling a plug to check where the moisture level might be. Do this at timed intravals after irrigating. In Most cases top dressing with a good organic material after a hollow core aeration will increase Field Capacity and Hydraulic Conductivity. You might contact an agronomist in your area to do a soil profile to see if this is the reason you are dry. It would be a lot cheaper in the long run and like you said water isn't getting any cheaper. Use it wisely.

[snmhanson]

Thanks for the input. The spreadsheet mistake was pretty simple. For each of our four pricing tiers I calculated the cost for ALL of the water above the minimum for that tier instead of only the water within the min and max for that tier. Then I added them all together thus just about doubling the cost of our water. It was a mistake but at least a mistake in my favor.

Critrical Care, so far the Fertigator seems to be working well. When I first hooked it up last year I put it before my pressure reducer and was pumping ~100 psi into it (which the manufacturer said it could handle) and I got a reverse flow so it ended up just pumping water into the fertilizer container. This spring I reinstalled it after the reducer and it appears to be working well now (at least mechanically). Once my grass greens up a little more I will get a better idea of how effective it is.

Ric, I just went out and bought a soil sample tool so I can at least get a better look at how well the water is penetrating and how quickly it is leaving the soil. I did have the soil tested before planting our grass and it was good except for one item which I adjusted according to recommendations. However, I don't think the tests covered alot of the things you are talking about. If my lawn doesn't continue improving I will take your advice and look further into those issues.

Matt