 watering smart watering smart you may have heard the phrase water lawns 1 inch a week while this is a good rule of thumb it is based on your lawn s water needs as averaged throughout the year our typical pacific northwest summers tend to be long hot and dry with rainfall at a minimum therefore it is likely that your landscape may require more water during the summer months and less water during the spring and fall months when the weather tends to be rainier and cooler the key to watering efficiently is to frequently adjust the amount you water throughout the growing season as the weather and your plant s water needs change  to do this you will first need to know how quickly your sprinkler distributes 1 inch of water   set a base schedule and adjust the watering schedule on a weekly basis using the consortium s weekly watering number   how to determine your sprinkler s output by following these four easy steps  place two consortium watering gauges at two different places within your sprinkler s spray range then run your sprinkler for 15 minutes    you may also use a tuna can and a ruler to conduct this test find the average amount of water in inches collected in your gauges to do this measure the amount of water in each gauge add these amounts together and divide by two this is the average amount of water your sprinkler puts out in 15 minutes this will provide you with a good guideline amount for increased accuracy repeat steps 1 2 several times placing the gauges at different distances from your sprinkler use this chart to see how much time it will take you to water one inch average water depth after 15 minutes total time needed to water 1 inch 18 120 14 60 12 30 34 20 1 15 set your base schedule  we recommend watering 2 times per week either before 10 am or after 6 pm when temperatures are cooler for example if after 15 minutes your gauges have 12 an inch of water in them you will need to water a total of 30 minutes per week to get the recommended 1 inch m t w t f s s minutes 15 15  take the next step  if you have an automatic sprinkler system you will need to program this base schedule  into your sprinkler s controller then you can use the weekly watering number to fine tune your system s settings to water your landscape as efficiently notes   an established lawn needs about 1 inch of water each week and more during hot dry spells however water needs vary from plant to plant  so it is best to check with your local garden center or landscape professional on your plant s specific watering needs  if runoff occurs you will need to run your sprinkler for a shorter time period so that you are applying only the amount of water that your soil can absorb  use watering gauges to figure out how much water your system distributes during this time and then figure out how many times you will have water each week to put down the recommended 1 inch per week  output output inch week output weather conditions weekly watering number weekly watering number number weekly watering schedule number inch week   outdoor  