Kansas City Lawn and Landscape Watering Guidelines

Kansas City’s Lawns and Landscapes will benefit dramatically if you know how to properly water them. There is no other homeowner controlled aspect of caring for your plants more critical than proper irrigation. It is also the number one mistake I see Kansas City homeowners doing

It is essential to first understand what your plants want in an ideal world. Most of our lawns and landscapes in Kansas City will thrive on 1.5” of water per week. This can come from either rainfall or irrigation. Ideally 1.5 inches would be applied in one long and slow watering. However, in Kansas City, our clay based soils have a hard time absorbing more than ½ inch of water per hour before water begins to run off the surface so we have to water very slowly – hard for sprinklers to do – or water on multiple days in smaller amounts. Counter intuitively, we want these watering cycles to be on successive days, not spread evenly through out the week since our goal is to water deep into the ground and not to keep the surface moist.

Knowing how much water we need is the first step – the next step is knowing how to apply that water and for how long. Most homeowners will either be applying water by manual sprinklers or an automatic irrigation system. Both require you to know how much water is applied in a given amount of time by your system.

To measure the output of your sprinkler heads…

1. Set a container with straight sides (I use a butter dish) in the middle of the sprinklers path. a Turn on the sprinkler and monitor the amount of water in the container.
2. Turn off the sprinkler when the amount of water in the can has reached one inch (measure with a ruler – it can be deceiving)
3. This is how much water that sprinkler system puts out in one hour.

Now, I know most of you will not take the time to accurately measure out your sprinklers output – despite its importance. So here are some rules of thumb for determining your sprinklers output. For automatic irrigation systems – spray heads (the ones that pop up and don’t move) typically need about 45 mins to put down 1” of water and rotors (the ones that sweep back and forth) need about 2 hours. So a generic program that I suggest for my customers is designed to put down 1.5” of water spread between 3 separate watering cycles. I set it so that the lawn gets watered Monday, Tuesday and Friday. This is a good compromise of watering deeply but also making sure that the water does not run off.. I set zones with spray heads to come on for 30 mins and zones with rotors to come on for 60 mins. This is adjusted if the soil is unable to absorb this amount of water. Also, all watering should be done to supplement mother nature. If she gives us ½” of rain then you can reduce watering by that amount.

For those of us unlucky souls who do not have automatic irrigation it takes a much longer to water our lawns. Most of the typical impact sprinklers used if set on full circle put out about 1/3 of an inch per hour. Since they water slower they can be left on longer. I usually suggest you water twice a week for 2 hours before moving the sprinkler. If you are only using the sprinkler in a half circle then you can cut that in half