 watering chart create a weekly watering schedule you may have heard the phrase water lawns 1 inch a week while this is a good general rule for most of the summer weather is constantly changing and so should your watering schedule step 1 get to know your sprinkler over watering is the most common problem in home landscapes since each sprinkler puts out water at a set rate knowing your sprinklers can help you determine when and how much to water your landscape you can use the consortium watering gauges to figure this out here s how place the consortium watering gauge and 25 other containers of similar shape and depth eg tuna cans at different distances from your sprinkler run the sprinkler for 30 minutes measure the total number of inches in the gauges cans and then divide the total by the number of cans to get an average depth step 2 decide when and how much to water since over watering is so common we recommend creating a thorough but infrequent watering schedule such as before 10 am or after 6 pm on wednesday friday and sunday step 3 use local weather conditions to help determine watering needs watering smart means thinking like a plant by using local weather conditions to help determine how much water your plants and lawn actually need use consortium s weekly et number to determine how much to water during each time on your schedule here s how divide the weekly et number by the number of times you will water that week this is the amount in inches you will water each time during the week for example  an et value of 1 means your lawn should get 1 inch of water that week if your sprinkler waters an inch each half hour you will set your sprinkler system to water 33 inches each time or 10 minutes using the example from step 1 some key things to remember when using et as a guide to creating a watering schedule your landscape include et varies for different plant types et changes depending on the weather et is affected by the amount of sun wind and air temperature step 4 tailor your watering to plant needs water needs vary from plant to plant for example turf generally requires more water than plants shrubs and trees setting your sprinklers to water turf separately from shrubs and perennials will allow you to tailor your watering schedule for each major section of your landscape determine which plant types are located in different areas of your yard and then use these general guidelines to create watering schedules to fit the needs for the different zones in your yard trees 50 of et until established then set to soak in july and august shrubs 50 of et lawns 100 of et shady areas 60 vegetables 75 of et  previous  learn learn more   outdoor  