One inch myth

[e Craig]

The advice that we frequently hear, and I've seen several times here, to water one inch weekly is a myth. Often we hear this from salesmen or homeowners who are very proud of their system[s]. Trying to do this will be wasteful of time, money and water. This would equate to 52 inches of rainfall a year! The plants in our lawns do not need these subtropical rain forest conditions to survive.

Watering, or irrigation if you will, should be performed only as needed to help the plants survive dry periods or other stresses, such as transplanting. If you have mostly native plants, or plants that have been well selected for your climate there should be only occasional need for watering.

May I suggest, try watering warily:
1. Water only as needed.
2. Water only where needed, not on paved areas.
3. Use methods that minimize waste such as drip irrigation, soaker hoses, and night watering if using sprinklers.
4. A schedule of occasional heavy watering is considered far better than frequent or light watering.
5. Try to wait for rain, watering carefully only as needed for survival.

Often, we are watering a lot because we are watering a lot. The plants have come to depend on the excess water and do not develop the root system needed to tap into the water table. That is, if they do not develop unhealthy conditions due to over watering. Further, if you have been helping build a healthy organic soil society, it can store a lot of water, as well as develop capillaries that will wick water from the water table up into the root zone.

The lawn and bed watering program we have found most efficient, in terms of water use and time involved, as well as plant response, is:

(1) Wait for the top two inches of soil to become dry.
(2) Apply enough water to saturate the top six inches of the soil.
( This will probably be done in the time it takes your sprinkler to fill a can to about one inch deep. )
(3) Return to step one.

Initially, some areas and plants may demand water sooner. Delay as much as possible, but don't lose your plants. Do keep stretching the intervals. The plant's roots will be encouraged to grow deeper to find the ambient water for its survival. Eventually, as the plants improve, you will even go weeks between waterings!

And in case of a drought, if your municipality should impose rationing, you will be able to skip several official watering days.

Take care.
Craig

[Kathe Kitchens]

Welcome to the forum, and it's good to see you are quite familiar with the basic tenets of healthy soil and its effects on our plants.

Addressing your "myth" statement. To my knowledge, this is meant to be a rule of thumb rather than a strict guideline. Funny how people will take a loose parameter and turn it into an iron clad rule. I have to give snaps to those who try to water this way, though. So many people, at least in my area, water "15 minutes a day, every day" (or some time based measure) and disregard soggy soil, sick plants and even torrential rains.

As a wise woman once told me, most statements that begin with "always" or "never", will require adjustment or even reversals in the future. :wink:

Thanks for your input. We enjoy sharing one another's experience and learning from each other.

Kathe :D

[e Craig]

Thanks for the welcome.

In all my browsing over the weekend, I saw & liked your messages.

I have posted replies to a couple topics in Trees and Pests and Diseases. Then, because I had seen many out of date topics that included watering, decided to try expanding the same messages here in the Gardener's Exchange. Perhaps to get the ideas in circulation ahead of the curve.

Re: your "wise woman"
Someone pointed out to me that most things considered "good" or "evil" are such only as they relate to moderation. i.e. liking money too much is greedy, too little is wasteful. Therefore "moderation" is the key. Moderation in all things, including moderation.

Still learning how to navigate this here forum. Any insights will be appreciated.

Take care.
Craig
.

[Kathe Kitchens]

We are of a mind. Moderation is indeed the key.
Thank you for your comments on my comments. :lol:
I'm sure we'll have some great interactions here.

Bright minds make for great discussions. I'm looking forward to it!
Kathe :D

[Nadine]

The texture of your soil will determine your water needs. Your water needs will change over time as mulch breaks down and as your soil improves. It is a good idea to keep a check on it at least once a year.You can use a fiberglass probe to determine how deep your water is going. :wink:

[merri]

Tell me more about this fiberglass probe...i have never heard of such a thing - is it something you buy or make?

thanks, merri

[Dchall_San_Antonio]

e Craig's (welcome, by the way) intentions are well received. However, he is simplifying, as we usually have to when we want to get our brains wrapped around complicated concepts. If we all had a 52 week growing season; rainfall evenly distributed from week to week; 50% humidity; day temps between 70 and 80 with night temps between 50 and 60; no more than 20% shade; and deep, loamy soil with 5% organic matter, I might agree with him. About half of Texas gets nearly 52 inches (or more) a year. Toward the east they get a lot more than 52 inches a year. Toward the west, a lot less. Toward the east there is more organic material in the soil. Toward the west there is either pure sand or sand covering caprock or alkaline gumbo (sometimes called caliche). Toward the east the humidity goes to 80%. Toward the west it is usually limited to 30%. Toward the east the hot summer day temp seldom passes 95 degrees. Toward the west it reaches 105 easily. In the Hill Country the soil sometimes has negative depth (protruding rocks) while the soil on either end of the state is much deeper.

If I could count on our expected 30 inches or so of rain to fall evenly divided by 52 weeks, I would probably not have to water. Better yet if I could count on the rain falling more heavily weighted toward the hotter time of year, that's even better.

If we all grew plants native to our specific neighborhood climate, I might agree with him. St Augustine is native to South Africa. In our climate if it does not receive water for several weeks, it dies. You could argue that St Aug is not a good species to have here, and that's a good argument; however, the problem is there are millions of St Augustine lawns across the South. Maybe some day we will all have to forgo the luxury of St Aug, but for now the reality is we must water about an inch a week during our respective growing seasons.

Quote: May I suggest, try watering warily:
1. Water only as needed. We would like to.
Quote: 2. Water only where needed, not on paved areas. I think this is universally accepted in Texas.
Quote: 3. Use methods that minimize waste such as drip irrigation, soaker hoses, and night watering if using sprinklers. Great idea. I agree.
Quote: 4. A schedule of occasional heavy watering is considered far better than frequent or light watering. Absolutely!
Quote: 5. Try to wait for rain, watering carefully only as needed for survival. I've given up on this one. I tried it a couple years and this year have gone back to weekly watering unless the rain hits by Tuesday evening. Otherwise, I'm watering Tuesday evening.

Quote: Initially, some areas and plants may demand water sooner. Delay as much as possible, but don't lose your plants. Do keep stretching the intervals. The plant's roots will be encouraged to grow deeper to find the ambient water for its survival. Eventually, as the plants improve, you will even go weeks between waterings! This has always been my advice, too. And it has been pointed out to me that it suffers from being a little too simple. If you live in arid sandy El Paso the situation will be much different than if you live in rainy organic Orange.

I realize there are plants that can live off the moisture in the dew and the air. But if we want to eat fruit and veggies, we must irrigate.

It's really hard to find a good map showing precipitation, but here's a pretty good one.

[Nadine]

I feel it is important to add some information that may or may not be new to you, but is important:

Plant native or adapted plants.
Let grass grow high. The higher the grass, the deeper the roots.
Also, watering deep will allow roots to grow deep. With shallow watering, comes shallow roots. Roots will not grow deeper than the moisture in the soil.
Have tall ornamental grasses along paved areas to lessen the amount of run-off.
http://www.txsmartscape.com/ is a great resource of information.

Educate yourself on rainwater harvesting, it is increasingly important.

[e Craig]

David,

I confess. I like short simple statements, like:

"Only the dead have seen the end of war." __Plato

"Moderation in all things, including moderation"

"Nobody goes there any more. It's too crowded." __Yogi Berra

But I also expect that the short answer should prompt more thinking and paying attention to the right things.
i.e. In keeping with the spirit of the old questions:

Q. When is the right time to plant a tree?
A. Twenty years ago. The second best time is today.

Q. When is the right time to prune?
A. When your saw is sharp.

I expect in the case of:

Q. How often should I water/irrigate?
The simple A. "When it is needed." Should lead us to the next
Q. "When it is truly needed?"

You, I, and others have talked and written at length about all the permutations involved in a complete answer. Knowing the ambient conditions will usually be needed to craft an answer.

All in all we're not so far apart. I say this, having also read your observation on the "Mulching weeds" topic in the "Weeds" forum. Mostly, I think that I am trying to say "Learn what is needed, as best you can in the time you have available". While it could seem that you are trying to craft a schedule, based upon the observed average needs. You may feel that something should be done at least weekly, while I have found that, by monitoring conditions, one may well have several weeks between waterings.

Ahhh well, this has became a longer "conversation" than probably either of us intended. Keep up the good work.

Take care.
Craig

[e Craig]

Merri,
That's not a magic fiberglass probe.
A long screwdriver, or such, will do the job. Anything that will poke a hole into the soil.

Take care.
Craig