 weekly watering number weekly watering number published here each thursday from aprilseptember the weekly watering number is the amount of water in inches that your lawn will need that week you can also use the weekly watering number for other types of plants by using these general guidelines  shrubs  50 of the weekly watering number trees  50 of the weekly watering number vegetables  75 of the weekly watering number new starts will require more water be sure to check with your local garden center or landscape professional for more specific information on your plant s water needs how do i get the weekly watering number  sign up to receive the weekly watering number via email each thursday april september or you can drop by this page for it who should use the weekly watering number  home gardeners and landscape professionals alike can use the weekly watering number to fine tune the amount they water each week so that it better reflects local weather conditions and their landscape s changing water needs how to use the weekly watering number the key to efficient irrigation is to adjust your watering schedule as the weather changes throughout the irrigation season automatic sprinkler systems  first determine your sprinkler s output  or how long it takes to water 1 inch of water then set your base schedule and use the water budget or percent adjust  feature to adjust your weekly watering schedule watering with a hose or a nonautomated sprinkler system  first determine your sprinkler s output  or how long it takes to water 1 inch of water then use the weekly watering number as a guideline to manually adjusting your watering duration or frequency why does the weekly watering number change  the weekly watering number changes with local weather conditions for example in the driest hottest part of summer it will be higher because more water is lost through evapotranspiration  or the combination of water lost from the soil through evaporation and from plants through transpiration why a zip codespecific weekly watering number  by narrowing the number down to a specific zip code the consortium is able to better take into account any variations in weather and rainfall that within your specific area for example the sellwood neighborhood in portland might receive significant rainfall from several showers while the nearby hawthorne area might now receive any rainfall as a result their weekly watering numbers would likely vary greatly that week where does the weekly watering number come from  the consortium contracts with a weather forecasting service to provide a free weather forecast and weekly watering number each thursday   weekly watering number watering needs weekly watering number weekly watering number plant plant weekly watering number weekly weather trends weekly watering number weekly watering number weekly watering number weekly watering number weekly watering number here here weekly watering number water water   outdoor  