MSU:Water lightly and frequently during summer?

[Duekster]

Originally Posted by Kiril

tmax = [1 / (P * b)] * {fo - P + fc * [ln (fo - fc) / (P - fc)]}

Do not be pulling that Hung So Cal School of irrigation crap on me Mister, in Texas we like charts, tables and graphs.

[R&S Lawn Care]

How deep for fescue blends. Ive found where seeds have sprouted that were washed into expansion joints of concrete. This grass is a little tougher than i had originally thought. Something i noticed is under the trampoline the grass has not wilted, whereas the grass outside shade of trampoline has wilted and some has gone dormant. Tttf planted last fall, watered once a week and its been 95-103 for a week or so. Appears ambient temp does not effect as much direct sunlight.
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[RigglePLC]

I am from Michigan. My irrigation runs lightly every day. And most irrigation companies will set up new systems this way. Grass does not think. Roots do not grow towards water, like we reach for a cold beer. My professor friend says that necrotic ring spot damage is much reduced by light daily irrigation. "Grass does not turn brown at night. Water during the hot part of the day. Use about 1/10 of an inch. Grass has maximum transpiration during the heat of the day. This is when the roots cannot keep up because they cannot pull enough water out of the soil fast enough to satisfy the transpiration demand."

We need some experiments guys--who is willing to conduct a side by side comparison?

Who is willing to dig up their grass to see how deep the roots are growing on the individual plots?

And we cannot forget about the soil type, percolation and aeration--roots need air. Sandy soil, fine, (but may drain too fast). Clay soil may be oxygen deficient or experience carbon dioxide at toxic levels in the deeper layers.

Low humidity and wind increase transpiration.

If there is a fungus situation--I usually recommend deeper--twice per week irrigation to reduce the average lawn humidity and hours per week of leaf wetness.

This is not easy. The top baseball groundskeepers are the experts. They have a critical eye for this. They can tell by looking if the grass needs water, but they want the soil firm for good ball bounce and playability. Greenskeepers just the same.

[ReddensLawnCare]

So you're saying that roots don't grow towards water. Why then do septic systems irrigation heads irrigation emitters constantly get clogged with roots
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[greendoctor]

I can see Riggle's point. When dealing with cool season grasses in extreme heat, you cannot exactly invite the lawn into your house or truck where the AC is keeping things at 75 or less. The light waterings in the day are for temperature management. Look at what golf supers do to keep bent grass alive. They do not water 1" once a week. No, in hot weather it is light waterings, up to several times a day if needed. I do it too, when it suddenly goes up to the 90s. You might be doing what the water board wants you to do, but the water board is not responsible for damaged grass from their recommendations.

[suzook]

Its unbelievable how after all these years of growing grass....we REALLY don't know if too much watering is bad. Myself.....I'm a believer of watering EVERY day of extreme heat. It has always worked well for my lawns.

[greendoctor]

If it works on golf courses and sports fields. I cannot imagine not instituting some means of temperature management on cool season grasses.

[Smallaxe]

Originally Posted by RigglePLC

... My professor friend says that necrotic ring spot damage is much reduced by light daily irrigation. "Grass does not turn brown at night. Water during the hot part of the day. Use about 1/10 of an inch. Grass has maximum transpiration during the heat of the day. This is when the roots cannot keep up because they cannot pull enough water out of the soil fast enough to satisfy the transpiration demand." ...

That is an interesting point about NRS, that I don't recall hearing about before...

Cooling the grass and wetting the leaves makes sense to a certain degree also... and I believe what is said about the sun being the culprit as well when it comes to the wiltdown...
As soon as a cornfield edge comes into shade you can see the 'relief' in those stalks... Morning Glorys will come back to life as soon as the shade hits the garden after afternoon sun... cloudy days in the 90s are less severe to the plants than 70s in full sun this time of year...

There really is no reason to assume that grass would behave/feel differently...

[greendoctor]

Non agronomists/horticulturists/plant physiologists have no business dictating irrigation practices.

It pizzes me off when those types tell people to water at night or to water infrequently when it is not appropriate to do so.

[Duekster]

Originally Posted by suzook

Its unbelievable how after all these years of growing grass....we REALLY don't know if too much watering is bad. Myself.....I'm a believer of watering EVERY day of extreme heat. It has always worked well for my lawns.

The dif is in areas where you have droughts and people are told to water twice a week and in some cases 1 per week.

Then your grass is not pre-stessed and dies.