With the amount of rain we had in May, it could be easy to forget that we live in a desert. We have been blessed with a good snowpack in the mountains over the winter to provide us with water for the current growing season. The way we use water reflects on our stewardship of this natural resource. How many people forgot to turn off their sprinkler systems during this rain event? It has been documented that about 70% of all landscape issues are due to over or under-watering. Here are a few questions that we all need to ask ourselves:

  • How much water are we using?
  • Do we know how much water our lawn, trees, shrubs and flowers really need?
  • What can we do to conserve water?

It is convenient to just turn that sprinkler clock on and go on with life, compared to checking it at least monthly and adjusting for the weather as needed. Let’s explore the answers to the previous questions.

Water usage and loss statistics

  • The Environmental Protection Agency has calculated that in the Western United States approximately 50% of the outdoor water we use during the summer is lost due to runoff (overwatering), wind, and evaporation. (epa.gov/watersense/statistics-and-facts)
  • In the continental US, we have approximately 40.5 million acres of turfgrass. That is more acreage than those used by the top 8 irrigated agricultural crops combined nationwide. All this turfgrass has an estimated water usage of 59.6 million acre-feet of water annually. (scienceline.org/2011/07/lawns-vs-crops-in-the-continental-u-s)

How much is 59.6 million acre-feet of water? To provide a visual of that much water, it would be twice the capacity of the Great Salt Lake just to water our lawns.

Different plant types have different watering needs.


  • water to a depth of one foot (enough to fill the root zone) twice a week during the hot summer months. In the spring and fall only water once a week if there is no measurable rainfall.

Trees and shrubs:

  • water enough to wet the soil to the depth of about two feet every one to two weeks during the summer.

Flowers and vegetables:

  • depends on what you are growing, but generally water to an average depth of six to twelve inches every three days.


  • water multiple times a day during the summer.

Changes that you can make to conserve water in the landscape:

Assess your turf grass needs

  • Make sure the turfgrass areas you have are functional (play area for kids or entertaining) and not just to cover space. Consider planting trees, shrubs or native plants with mulch to fill unneeded turf areas.

Evaluate your irrigation system

  • Sprinkler system components wear out over time. Check your system to make sure it is functioning efficiently.


  • Adding a four- to six-inch layer of mulch can cut your water usage by 50%.

Install drip tube in place of spray heads for tree and shrub plantings

  • Drip tube along with a good mulch will reduce the amount of water needed to keep the trees and shrubs healthy and put the water into the root zone.

Update irrigation equipment (nozzles, controllers, valves)

  • There are many new irrigation products on the market that can deliver water more effectively. The MP Rotor nozzles that send out multiple streams of water on a flatter trajectory. Sprinkler controllers that have WIFI compatible and connect to a local weather source to make adjustments for you. The EPA also has a Water Sense stamp that if located on the irrigation product means that it has been proven to reduce water usage up to 35%.

Incorporate native plants into the landscape

  • There are many beautiful native plants that take much less water than our traditional landscape plants and once established, get by with little to no supplemental irrigation.

Group plants according to water needs

  • Lawns, vegetables, flowers, trees, shrubs, fruit trees, etc. all have different water needs. Grouping plants according to their water needs allows us to be more effective with our water usage and not over or underwater the plants in our landscape.

We have had a number of good water years lately, but history has proven that we will have drought years in the future. Let’s take the time now to become good stewards of the water we have, so when there is a shortage and we are reminded that we do live in a desert, we are prepared to appreciate and conserve our water.

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Garden Wise is presented by the Magic Valley Master Gardener Association. We will try to answer questions of general interest submitted by the community. Email questions to gardenwise@cableone.net.


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