Irrigation Question

[lVlrBoJang1es]

I'm very familiar with the mantra of 1" cumulative water input per week (via natural or irrigation), deeply and infrequently. I also realize that, similar to most other lawn care guidelines, this "mantra" is purely a recommendation since other factors can serve better as signs that your lawn needs a drink…

Since I’m far from an expert and my lawn behavior is inconsistent for other reasons, I’m going to do my best to abide by the 1"/week rule. I recently had an irrigation system installed in my yard and I will actually have the ability to accomplish this weekly 1” by reasonable means this year.

I've heard a lot of mixed information in my research on the proper way to achieve this 1"/week when rain is involved. The part that I’m trying to wrap my head around is the element of Mrs. Unpredictable Mother Nature.

Consider the following:

Scenario 1
Does it make sense to follow up a rain storm with watering? For example, if it hasn’t rained in 6 days, and on the 7th day 0.5” drops. Is it best to irrigate for another 0.5” (assuming I can do so without puddling and runoff) immediately after the rain storm? This would be similar to dropping down 1” all at once and thus following the “deeply and infrequently” rule.

Scenario 2
Any tips for irrigating when Mother Nature refuses to follow the “infrequent” part and the weekly total doesn’t equal 1”? For example, no rain for 2-3 days, and 0.1” called for on days 4, 5, 6, and 7 (0.4” total). I drop down 0.5” on day 6, then the storm on day 7 (predicted 0.1”) swells into 0.75”. Now my lawn is drowning during that 7th day storm (total of 1.65” over 4 days)!

Scenario 3
Extreme drought – no rain for 2-3 weeks. I’ve heard mixed reports on whether or not it’s best to drop 1” all at once or break it up into 2x0.5” watering. I think that breaking up the watering would allow more leeway for Mrs. Unpredictable Mother Nature.

On a side note:
I was honestly thinking of writing some python code to perform a daily scrape of reported rian accumulation averaged from several reputable weather source websites, then compiling the gathered data into a shifting 7 day window. Then I stumbled across the option of Wi-Fi capable rain gauges. Does anyone have any experience with theses Wi-Fi rain gauges? I was hoping such a device would offer immediate, remote, feedback that's more accurate than looking at an “analog” rain-collector-gauge that may half evaporate by the time I get home from work.

Am I over thinking things?

[Riverpilot]

I'm not sure about the irrigation part.. I'm also getting irrigation installed, just waiting for the weather to cooperate at the moment.

As for the rain gauge, I have a acurite, which I purchased from their web site. Depending on how much you want to spend, they have all kinds of applications. I've had mine since last summer, and it works very well. Accurate, etc...
The only thing I have a bit of problem with is the wi-fi signal. The weather station, with rain gauge etc... sends out a signal to a receiver (which connects to your wi-fi router), that receiver needs to be put in a good spot.

My new irrigation controller (Hunter) is going to be able to use my weather station to base when to turn on/off irrigation, etc..

[lVlrBoJang1es]

As for the rain gauge, I have a acurite, which I purchased from their web site. Depending on how much you want to spend, they have all kinds of applications. I've had mine since last summer, and it works very well. Accurate, etc...
The only thing I have a bit of problem with is the wi-fi signal. The weather station, with rain gauge etc... sends out a signal to a receiver (which connects to your wi-fi router), that receiver needs to be put in a good spot.

Nice, i'll look them up. I haven't researched WiFi rain gauges yet. I'm surprised that it's not a stand alone device that connects to your WiFi network and uses a transmitter/receiver setup instead.

My new irrigation controller (Hunter) is going to be able to use my weather station to base when to turn on/off irrigation, etc..

Nice, you'll love it! Mine was installed with at Hunter Pro-HC controller. The web based phone app gives you great control! Make sure you thoroughly spend some time setting it up and exploring every feature!

My controller only supported 2 sensors. I decided to go with a soil moisture sensor and a flow meter. I opted out of the weather sensor because I figured I could rely on the controller polling local stations for weather data. I didn't realize that in order to have access to the NEAREST minor weather stations (1-2 miles), you needed to pay a monthly subscription. Without that subscription the nearest major station i can connect to is ~ 4 miles away. Still "good enough" in my book for everything but rain coverage. Looking back, i'd probably swap the soil moisture sensor for the weather gauge. I think you made the right choice!

Thanks for the reply!

[Riverpilot]

Acurite has all kinds of different products, so I'm not 100% sure what other set ups they have.

The Hunter Pro-HC is the one I asked for as well. I'm down in a valley of sorts, so what the airport weather is reporting, which is out in the open, can be quite a bit different than what I'm experiencing at my house. Especially wind.

[bernstem]

Scenario 1
Does it make sense to follow up a rain storm with watering? For example, if it hasn’t rained in 6 days, and on the 7th day 0.5” drops. Is it best to irrigate for another 0.5” (assuming I can do so without puddling and runoff) immediately after the rain storm? This would be similar to dropping down 1” all at once and thus following the “deeply and infrequently” rule.

Scenario 2
Any tips for irrigating when Mother Nature refuses to follow the “infrequent” part and the weekly total doesn’t equal 1”? For example, no rain for 2-3 days, and 0.1” called for on days 4, 5, 6, and 7 (0.4” total). I drop down 0.5” on day 6, then the storm on day 7 (predicted 0.1”) swells into 0.75”. Now my lawn is drowning during that 7th day storm (total of 1.65” over 4 days)!

Scenario 3
Extreme drought – no rain for 2-3 weeks. I’ve heard mixed reports on whether or not it’s best to drop 1” all at once or break it up into 2x0.5” watering. I think that breaking up the watering would allow more leeway for Mrs. Unpredictable Mother Nature.

Maybe you are overthinking, maybe not.

1 - yes, it makes sense to supplement mother nature if it isn't enough rainfall and there isn't any likely to come up in the near term. Many member do exactly what you describe.

2 - 0.1 inches doesn't count. It may not even get to the soil if your lawn is thick enough and, if it does, it won't add enough to the soil to matter. As for mother nature not obeying the forecast, you can't do anything about it. Do your best and deal with what actually happens. FWIW, more rain than the lawn needs just runs off or washes below the root zone. Consider the lawn fully watered and plan for an inch in one week.

3 - This is an interesting question. The answer is that it depends. Generally, you want to water enough to fill the root zone when or just before the turf start to show drought stress. This usually is when one inch of water has evaporated and been used by the grass. For some lawns it may be 1/2 inch. For others it may be 1.5 inches. It also varies by soil and grass type, but 1 inch is a good starting point.

As you might expect, when it is hotter, the ground looses water faster. You can calculate the water loss (and some irrigation controllers do the calculations), but you can also watch the grass. When it shows stress, give it an inch of water. That may be every 5 days. It may be every 2 weeks. Either way it gets an inch of water when it shows stress. Of course, there may be reasons why the one inch rule doesn't work for your lawn, but it is still a good starting point. Use common sense. If the lawn is showing stress every day, for example, it is unlikely the lawn is loosing an inch of water every day so start looking for other causes.

[andy10917]

Mr. Bo, I think you need to read your own writings. I see a heavy focus of rules, and a repeated irritation with Mother Nature's refusal to meet your expectations and rules. Before you got into lawncare, did you have these same expectations that Mother Nature behaved like that? If not, who is the one that doesn't match reality?

In 46+ years of doing lawns and gardens as a major, major hobby I've yet to meet a person that focuses on a rule-based approach be in the Top 10% of the best lawns/gardens - every one of the most successful owners worked with what Mother Nature dealt by adapting to what they saw, week by week and month by month. As Bernstem stated, it isn't about 1" of water or 7 days between applications. Those are just easy starting places to use while you change behaviors. D&I irrigation is about deep watering and supplying it just as the earliest signs of stress appear. You've got 3 questions about edge-cases right now - over time you'll develop a hundred of those questions/answers. Then you'll start noticing that Rule 47 and Rule 83 offer different answers. You'll go nuts and say the rules don't work. Read and interpret the intention of the "rule", and use your eyes to make a decision in your yard, in your situation, today. You'll get better answers and far-better results.

[lVlrBoJang1es]

Thanks Andy and Bernstem!

Andy; I'm guilty as charged. I'm an electrical engineer and my mind lives in a 1 or 0 world, yes or no - no room for grey. I think this nature about me is why the challenge of lawn care is appealing. It's a realm that's completely different than what I'm used to!

I've restricted my posts to the Basics 101 forum, because I've only been doing this for a year... That said, I'm don't have a keen eye yet for a stressed lawn. All the recommendations seem subjective to me - I feel like I can always see my steps in my lawn, it only seems to lose its color I between milorganite apps (I'm doing 1/2 bag rate every 2 weeks at the moment), and my lawn doesn't feel "crunchy" unless it's dead.

I know developing the feel for a stressed lawn goes beyond what I've mentioned, but in my green-horn stage I'm don't have anywhere near enough experience to stray from most of the basic recommended rules.

Thanks for the discussion guys!

[bernstem]

You can get a feel for how your lawn responds to drought stress by allowing an area to become progressively more stressed over time. Only do it in a small area in case you overdo the test and end up with dead turf, but closely observing grass that isn't being irrigated will give you a good feel for what it looks like at different stages. If you want to feed your need for details at the same time, take notes on how the turf looks/feels daily. For what it is worth, different grass types respond to drought stress differently.

If nothing else, it will give you a better feel for your lawn and provide some referential information for the future.

[Green]

Rules are good, because they help us learn and organize our thoughts and keep records. I'm in the stage now where all the rules are melding together to form intuition on what works for my own situation. As someone who has been serious about the lawn hobby for 7 years now, I'm constantly thinking about and analyzing principles, results, etc. Someone like Andy who has been at it 6 times longer has more intuition, and won't need to analyze against guidelines as much, until he decides to try a new idea out.

As someone who is thinking a lot about irrigation the last couple of years, here are my current ideas...

Scenario 1: I often do follow such a rain with an irrigation, but only if I think the lawn is due for a deep watering. Sometimes, I won't...especially if it's not showing signs of drought stress starting yet. In these cases, the 0.5-inch of rain generally elongates the interval until the next deep watering is required. Maybe 2 days...sometimes 4...depends on how drought stressed the lawn was, the temps, etc.

Speaking of elongating the interval: Sometimes, I'll do the same but in reverse. Like this past weekend. On the night of May 13th, we got 1.3 inches of rain. In the days after, we had 3 days of 90+ heat. I figured from experience that the main front lawn was going to need a deep irrigation in about 6 days. But there was rain in the forecast and I was trying to lengthen my mowing interval due to an herbicide application. So I set the sprinkler system to water a half inch on Friday morning. It never watered because I messed up the clock on the timer trying to set daylight saving time. By Friday, drought stress was evident. So I set it for Saturday morning instead and did a little shallow hand-watering of the very worst areas (near the curb) on Friday. Saturday morning, it watered a half inch. Today, Monday, the rain started. 1.2 inches forecast. End of story.

Scenario 2: Ok, but now, watching the news, it looks like the forecast is changing. It's good, because tomorrow is supposed to be dry in the afternoon, so I can mow, according to the weatherman (I really need to thank him for always mentioning mowing/fertilizing opportunities in his forecasts). However, how many days is it going to take to get that inch of rain now that the forecast changed? Thankfully, the temps are on the low side, so the ET rate is low. That increases the chance that any water that reaches the root zone will stay there, and the next rain a day or two later will increase the soil moisture levels and depth. Will it really be a "deep" irrigation event though? I don't know. All I can do is use the rain gauge to measure the amount of rain, and the intuition I'm in the process of developing (a fun process!) to predict what will happen and then compare it to what actually happens. This includes how the grass reacts in the days afterward. I know from experience that what I'm doing isn't going to screw anything up. If I really wanted to, I could use a soil moisture probe, which I don't have and don't want to use.

Scenario 3: I figured out that my side front lawn, which has a slope on one side, and some tight soil on that slope, doesn't react well with one irrigation session of one inch a week in the middle of Summer. So what I've started doing, is adding in a second session on the third or 4th day after the deep irrigation. Somewhere around 0.5 inch. It still drought stresses, but not as badly after adding in the supplemental watering. I'm still getting one deep session (whether the soil there can handle that is debatable though) per week, and just adding a second, lighter one.

I've also found that rain is superior to artificial irrigation. It's just more even, and usually at a better rate that the soil can absorb better.

Now, what about no rain for 2+ weeks? That's happened. Let's not call it extreme drought, since it can happen even without an extreme drought occurring. A lot of what you do hinges on the ET rate...how hot it is and how much evaporation and transpiration are occurring as a result. If it's July and that's happening, you might be justified in trying a 0.5+0.5-inch strategy. Or, you might use my strategy of one inch plus a half inch a second time that week. I know it's tough to balance everything...grass health, rain, water usage, etc. Now, if it's April and it's 50 degrees as the high, you might go 2 or more weeks easily between rain events.

[lVlrBoJang1es]

Rules are good, because they help us learn and organize our thoughts and keep records. I'm in the stage now where all the rules are melding together to form intuition on what works for my own situation. As someone who has been serious about the lawn hobby for 7 years now, I'm constantly thinking about and analyzing principles, results, etc. Someone like Andy who has been at it 6 times longer has more intuition, and won't need to analyze against guidelines as much, until he decides to try a new idea out.

As someone who is thinking a lot about irrigation the last couple of years, here are my current ideas...

Scenario 1: I often do follow such a rain with an irrigation, but only if I think the lawn is due for a deep watering. Sometimes, I won't...especially if it's not showing signs of drought stress starting yet. In these cases, the 0.5-inch of rain generally elongates the interval until the next deep watering is required. Maybe 2 days...sometimes 4...depends on how drought stressed the lawn was, the temps, etc.

Speaking of elongating the interval: Sometimes, I'll do the same but in reverse. Like this past weekend. On the night of May 13th, we got 1.3 inches of rain. In the days after, we had 3 days of 90+ heat. I figured from experience that the main front lawn was going to need a deep irrigation in about 6 days. But there was rain in the forecast and I was trying to lengthen my mowing interval due to an herbicide application. So I set the sprinkler system to water a half inch on Friday morning. It never watered because I messed up the clock on the timer trying to set daylight saving time. By Friday, drought stress was evident. So I set it for Saturday morning instead and did a little shallow hand-watering of the very worst areas (near the curb) on Friday. Saturday morning, it watered a half inch. Today, Monday, the rain started. 1.2 inches forecast. End of story.

Scenario 2: Ok, but now, watching the news, it looks like the forecast is changing. It's good, because tomorrow is supposed to be dry in the afternoon, so I can mow, according to the weatherman (I really need to thank him for always mentioning mowing/fertilizing opportunities in his forecasts). However, how many days is it going to take to get that inch of rain now that the forecast changed? Thankfully, the temps are on the low side, so the ET rate is low. That increases the chance that any water that reaches the root zone will stay there, and the next rain a day or two later will increase the soil moisture levels and depth. Will it really be a "deep" irrigation event though? I don't know. All I can do is use the rain gauge to measure the amount of rain, and the intuition I'm in the process of developing (a fun process!) to predict what will happen and then compare it to what actually happens. This includes how the grass reacts in the days afterward. I know from experience that what I'm doing isn't going to screw anything up. If I really wanted to, I could use a soil moisture probe, which I don't have and don't want to use.

Scenario 3: I figured out that my side front lawn, which has a slope on one side, and some tight soil on that slope, doesn't react well with one irrigation session of one inch a week in the middle of Summer. So what I've started doing, is adding in a second session on the third or 4th day after the deep irrigation. Somewhere around 0.5 inch. It still drought stresses, but not as badly after adding in the supplemental watering. I'm still getting one deep session (whether the soil there can handle that is debatable though) per week, and just adding a second, lighter one.

I've also found that rain is superior to artificial irrigation. It's just more even, and usually at a better rate that the soil can absorb better.

Now, what about no rain for 2+ weeks? That's happened. Let's not call it extreme drought, since it can happen even without an extreme drought occurring. A lot of what you do hinges on the ET rate...how hot it is and how much evaporation and transpiration are occurring as a result. If it's July and that's happening, you might be justified in trying a 0.5+0.5-inch strategy. Or, you might use my strategy of one inch plus a half inch a second time that week. I know it's tough to balance everything...grass health, rain, water usage, etc. Now, if it's April and it's 50 degrees as the high, you might go 2 or more weeks easily between rain events.

Wonderful post Green! Thank you for taking the time to share your experiences. This is exactly what I was hoping for.

I especially like the part about the elongation of the interval until the next deep watering. I once read something like this, but for some reason my brain passed over it. Your explanation makes an incredible amount of sense though in regards to avoiding over watering (with the concern of waste/runoff); if i were to stack an additional of 0.5" irrigation on top of a 0.5" rainfall and a freak storm materializes some days after...

Man I love this place

[Green]

You're welcome.

To continue with more info...

I'm glad I chose not to water this morning. We only got like 1/8th-inch yesterday instead of 1 inch (the weather really changed). But I need to mow later. So that factored into my decision. So did the fact that it's supposed to rain again later this week. The lawn isn't drought stressing that badly (though it might get worse after I cut...we'll see), so there's leeway. At the same time, I have to remember that I did overseed some areas last Fall. So I don't want to drought stress the new grass.

If we don't get a full inch later this week, I'll definitely be doing the top-off thing.

[rtomek]

If you want rules you can get even more in depth with a smart controller. If you have a EPA watersense approved controller it is required to take into account all kinds of rules. Based on your soil type, it determines how much water your soil can hold and how much water your soil can even absorb based on precipitation rate. It also determines the daily evapotranspiration rate, so it can calculate the water budget deficit/surplus and provide only the water to make up the deficit plus cycle through zones to give the soil time to soak up the water from each cycle with no run-off.

I picked one up last year, and having it automated instead of worrying and guessing about it has already made the purchase worth it to me.

[lVlrBoJang1es]

If you want rules you can get even more in depth with a smart controller. If you have a EPA watersense approved controller it is required to take into account all kinds of rules. Based on your soil type, it determines how much water your soil can hold and how much water your soil can even absorb based on precipitation rate. It also determines the daily evapotranspiration rate, so it can calculate the water budget deficit/surplus and provide only the water to make up the deficit plus cycle through zones to give the soil time to soak up the water from each cycle with no run-off.

I picked one up last year, and having it automated instead of worrying and guessing about it has already made the purchase worth it to me.

I recently had an irrigation system installed which included the Hunter Pro-HC controller. It connects to local weather stations as well as sensors in my yard to devise its own watering schedule and adjust accordingly via the HydraWise software.

Currently, I'm still dealing with a lawn that was recently overseeded in Fall of 2016 (and i'll probably do another overseed this fall to repair the thinning caused by the machinery damage during the install). As such, I'd like to precisely control the irrigation at the moment. I can't wait to utilize these features further down the line though when my turf is more established!

This morning I was approached by someone at work who was asking for lawn advice. Mind you, I've only shown pictures of the progress i've made in my lawn over the first year in my house to a few people at work and this person was NOT one of them - i'll take it as a compliment! Right away this gentleman told me he watered his lawn every day, as well as a few other "poor" practices. When i started to explain the benefits of "deep infrequent" watering, I told this guy I'd send some reputable articles describing the practice and benefits. One of my first resources I turn to (being a MSU grad myself) is the MSU website - he'd probably disregard an enthusiast forum site (like ATY) just based on the fact that it was a forum format.

I found this article quite interesting from the MSU site:
http://msue.anr.msu.edu/resources/irrig ... er-quality

Particularly these parts:

Light, frequent applications of water are much more productive than heavy (soaking) applications once a week.

Research at Michigan State University indicates that damage from certain turf diseases and insects are reduced when light, frequent (daily) irrigation is used compared to a heavy, infrequent irrigation. Light, frequent irrigation corresponds to 0.1 to 0.2 inches of water for each irrigation event.

It goes on to talk about when watering restrictions are in place that prevent watering during the afternoon:

The concept is still the same; to produce a high quality lawn it is best to apply smaller amounts of water more frequently than to apply a large amount in one irrigation event. In these circumstances irrigating from midnight until 6 a.m. is acceptable.

The two below are from the .pdf version:

The best time of day for watering is early afternoon just before the highest temperature period of the day.

You should slightly increase the amount during periods of high temperatures and sustained wind to make up for evaporation.

Quite the head scratcher. I know the article has environmental friendly practices in mind and reducing water usage, but some of this stuff is quite contradicting not just towards what is generally "best practice" but also eco friendly motives as well...

[bpgreen]

Were the parts that recommended frequent light watering talking about all year, or were they geared toward the hottest parts of the summer? If you search for syringing on the forum, you'll find discussions of using this technique during the heat of the summer.

[lVlrBoJang1es]

Were the parts that recommended frequent light watering talking about all year, or were they geared toward the hottest parts of the summer? If you search for syringing on the forum, you'll find discussions of using this technique during the heat of the summer.

I thought syringing was a practice used merely to lower canopy and soil temperatures and thus most, if not ALL, of that water was expected to evaporate? I was under the impression that syringing was an attempt to mimic perspiration rather than actually supplying the soil with water.

I think the article is focused on actual irrigation practices, not lowering soil/canopy temperatures.

I don't know, i'm confused

[rtomek]

As far as the MSU article is concerned:

The water timing makes sense from a botany perspective, give the plants water when the plants need it most. The real-world problem is that a lower percentage of the water that comes out of the sprinkler at that time actually makes it into the soil due to a higher evaporation rate, so you have to increase how much water you use. Municipalities make their irrigation rules based on water conservation, not based on turf quality.

The article seems to be referring to some grad student's study about dollar spot not being as bad with LF (low & frequent) compared to DI (deep and infrequent) irrigation, and it cites a bunch of papers that lean both ways on the subject. I also think DI means too many different things depending on what paper I'm reading. Some papers consider it once every 2 days, some every 4 days. In some papers it is defined as visible turf stress - where they irrigate on 7 day intervals in the spring and fall, and 3 day intervals in the heat of summer, and is what senior members preach. Either way, the concept of DI being once a week, fixed, no matter the time of year is discordant with most of the journal articles I've read - unless they're actually studying drought-induced stress.

[bernstem]

The rules need to be bent/changed based on local conditions. In St. Louis, I water ~1 inch every 7-9 days in the spring and fall and 0.5-0.75 inches every 2-4 days in the summer. The turf just does better in my lawn with more frequent lighter irrigation when it is 90+ for several weeks.

The light frequent irrigation recommendation in that article seems to specifically reference diseased lawns. Once you have a fungal outbreak, the general rules go out the window and you need to start managing the lawn around the disease. That changes everything including fertilization, mowing and irrigation.

The most important thing is to watch and know your lawn and respond to what is happening. The irrigation "rules" are more like guidelines and need to be adjusted to local conditions.

[nocsious]

I run my sprinklers manually unless I'm leaving town. It's not a big deal really as it's only once a week or perhaps twice a week in the heat of the summer. I may give my grass a brief afternoon cool down if it's 95 degrees plus but that's not a true watering. If I notice the need for water, I simply go in the garage and turn the sprinklers on to run the next morning. That works for me.

[Dchall_San_Antonio]

I'm still stuck on your original few sentences.

I'm very familiar with the mantra of 1" cumulative water input per week (via natural or irrigation), deeply and infrequently. I also realize that, similar to most other lawn care guidelines, this "mantra" is purely a recommendation since other factors can serve better as signs that your lawn needs a drink…

One inch once a week is only for the hottest heat of summer - in Phoenix. In your area you may never need to water a full inch in a week. Over the years I have tried to reduce "deep and infrequent" into something meaningful to everyone. Here's what I have.

Watering: Deep and infrequent is the mantra for watering. This is for all turf grass all over the place. Deep means 1 inch all at one time. Put some cat food or tuna cans around the yard, and time how long it takes your sprinkler(s) to fill all the cans. Memorize that time. That will be the time you water from now on. My hose, sprinkler and water pressure takes 8 full hours to fill the cans. Your time will likely be less. I like gentle watering. As for watering frequency, that depends on the daytime air temperature. With temps in the 90s, deep water once per week. With temps in the 80s, deep water once every 2 weeks. With temps in the 70s, deep water once every 3 weeks. With temps below 70, deep water once a month. Note that you have to keep up with quickly changing temps in the spring and fall. This deep and infrequent schedule works in Phoenix and in Vermont, so it should work for you. The reason for deep and infrequent is to grow deeper, more drought resistant roots and to allow the soil to dry completely at the surface for several days before watering again. If it rains, reset your calendar to account for the rainfall.

Does that help you understand 'the rule'?

[RockinMyLawn]

I'm still stuck on your original few sentences.

I'm very familiar with the mantra of 1" cumulative water input per week (via natural or irrigation), deeply and infrequently. I also realize that, similar to most other lawn care guidelines, this "mantra" is purely a recommendation since other factors can serve better as signs that your lawn needs a drink…

One inch once a week is only for the hottest heat of summer - in Phoenix. In your area you may never need to water a full inch in a week. Over the years I have tried to reduce "deep and infrequent" into something meaningful to everyone. Here's what I have.

Watering: Deep and infrequent is the mantra for watering. This is for all turf grass all over the place. Deep means 1 inch all at one time. Put some cat food or tuna cans around the yard, and time how long it takes your sprinkler(s) to fill all the cans. Memorize that time. That will be the time you water from now on. My hose, sprinkler and water pressure takes 8 full hours to fill the cans. Your time will likely be less. I like gentle watering. As for watering frequency, that depends on the daytime air temperature. With temps in the 90s, deep water once per week. With temps in the 80s, deep water once every 2 weeks. With temps in the 70s, deep water once every 3 weeks. With temps below 70, deep water once a month. Note that you have to keep up with quickly changing temps in the spring and fall. This deep and infrequent schedule works in Phoenix and in Vermont, so it should work for you. The reason for deep and infrequent is to grow deeper, more drought resistant roots and to allow the soil to dry completely at the surface for several days before watering again. If it rains, reset your calendar to account for the rainfall.

Does that help you understand 'the rule'?

How do you handle Evapotranspiration & runoff?

I have a Rainbird Irrigation controller & they reference this in their litraturee & in their blackbox algorithms but I am not sure what it's really affecting.