How Long Should I Water My Lawn in Idaho?

How Long Should I Water My Lawn in Idaho?

Many people have been requesting a monthly lawn watering guide.  I have hesitated to create it for a while because it is a really difficult question to answer in a broad sense.  There are just too many variables.  So, what I decided to do is separate the year into its seasons.  From there, I can tell you what I do for my lawn.  In the end, there will be a list of some of the things you should look out for and be aware of.  The most important thing to remember is, our lawns only need one inch of water a week to be happy.  How they get that, will vary from lawn to lawn.



In early spring lawn watering is a fairly easy job.  We don’t really need to do a whole lot.  Sure, sometimes we can have a dry spring, more often than not we have plenty of rain to accommodate our lawns watering needs. Starting around late March or early April, begin watering your Lawn once a week.  You should set your sprinklers to run for approximately 40-50 minutes per station.  You can break this rule if you are applying fertilizers and/or weed/bug killers, as these will need to be watered in.

There is a very important concept to understand as we go through the year.  The amount of time you water is going to stay pretty much the same through the year.  What you will change, is how many times during the week you water.  You should always be watering for around 40-50 minutes per station.  This assures that the water will saturate the soil, watering the grass roots as far down as they would like to go.



The first official day of summer is in June.  I have been around long enough to know that it can start a lot earlier than that.  As the temperatures rise in mid/late spring you will want to add a second day to your watering schedule.  I like to make my watering days at this time of year, Monday and Thursday.  As we go further into summer I will add days to my schedule; the amount of time I water remains consistent.  So I go from Monday/Thursday to Monday/Wednesday/Friday.  I like to do it this way so the lawn is dry Saturday morning so mowing will be easier.  When it starts to get really hot I will turn the sprinklers on manually after I am done mowing Saturday.

This schedule will work for most people.  However, I want you to know I adjust my sprinklers constantly.  I may add ten minutes or take away ten minutes.   I may run the sprinklers all the way through after it was just watered.  I believe these regular adjustments to your regiment are the key to watering properly.


Ah, fall, my most favorite of seasons.  Once we get to Labor day we can usually start to dial back on the watering.  As the temperatures come back down, begin removing watering days from your schedule.  It is not uncommon for irrigation water to get turned off before our lawn is done with it.  So you may need to use house water.  This is why I like to keep a few small sprinklers handy.  This way I can ensure my lawn was the water it needs to remain healthy as it slips into dormancy.

Watering New Sod or Seeded Lawns

New lawns will require a slightly different approach. New seedlings will need a constant supply of water. However, too much water will rot the new tender roots. Your new seedlings need to be watered for 5-10 minutes 2 to 3 times per day. As the seedlings grow, you can reduce the number of times per day you water and increase the duration. So adjust from 2-3 times at 5 to 10 minutes, to 1-2 times at 15-20 minutes. Adjust to once per day for 20 to 30 minutes, and finally adjust to the regular maintenance watering as noted previously. Sod is watered similarly to seedlings. However, it will have more roots than seedlings, so you can start at once to twice a day for 15 to 20 minutes and adjust to a regular maintenance schedule.


As promised, here is a list of tips and tricks that help me get through the watering season.

  • Water deep. Our grass likes to grow its roots down a few feet into the soil.  It won't be able to, if the water never gets down there.
  • Grass that isn’t getting enough water will begin to look bluish/gray.  This is an early warning sign that a sprinkler isn’t doing its job.
  • There are two types of automatic sprinkler heads (there is a third that isn’t used much anymore).  We’ll call them gear drives (rotors), and fan spray.  Gear drives cover large areas and need to be run for a longer amount of time.  Fan sprays cover a smaller area and don’t usually need to be run as long.
  • Shady areas of the lawn need less water. This seems like a no-brainer; if you can hear a squishy sound when you walk on your lawn, it’s getting too much water.
  • Sandy soils drain very quickly.  Splitting up your watering times may be necessary.  Change your program to run 25 to 30 minutes twice a day on your scheduled watering days, instead of 40-60 once a day.
  • Lawns on a hill will tend to shed a lot of water.  Splitting your watering times may be necessary.

I hope this helps shed a little light on how to water your lawn.  Over the years I have found that small adjustments to my watering schedule are imperative to keeping the lawn in great shape.  Remember if you ever need anything, there is a Zamzows close by.