In Bend and Central Oregon we are fortunate to have access to an internet based service that provides information on the amount of water lost (and so needed) by our plants and grass. The term for this is ET which is short for “evapotranspiration.” This amount peeks in mid July allowing us to compare the current week to that “mid July baseline” or MJB and adjust our irrigation “water budget” accordingly. If you are interested in learning more about how you can use this information to both save water and be comfortable that your plants and grass are getting the water that they need, please email gardengenie@bendbroadband.com so that Heart Springs can set up a free class to share the info and tips.

If you are already using this process here is the ET data and water budget percentage for this week.  The total ET for the last 7 days: May 6 through May 12 is 1.35 inches for Bend, which is 64% of the MJB.

Previous Weekly Data:

April 29 through May 5 is 1.13 inches for Bend, which is 54% of the MJB.

April 22 through August 28 is 1.21 inches for Bend,which is 58% of the MJB.

Oct. 16 through Oct. 22 is .5 inches for Bend, which is 24% of the MJB.

According to the OSU Extension Service, our plants, shrubs and trees need water every 6 to 8 weeks in the winter. Our snowfall usually “covers” this need adequately but remember those plants that are close to the house and under eaves or decking. You may need to shovel some snow around them when we have a new snowfall.

Oct. 9 through Oct. 15 is .53 inches for Bend, which is 25% of the MJB.

If using 25% causes your run times to be really short, you may want to decrease the number of times you water each week and adjust the percentage.

Here is what I will do:

I normally water on odd days or 3.5 times per week. I have changed to 2 times per week. To adjust the percentage I multiply 25% by 3.5/2 like this .25×3.5/2 = .44 = 44%

I keep the same watering time settings I have used all along, change the watering schedule from odd days to a custom schedule watering two days a week and enter 51% for this week’s percentage.

Oct. 2 through Oct. 8 is .61 inches for Bend, which is 29% of the MJB.

Sept. 18 through Sept. 24 is 1.10 inches for Bend, which is 52% of the MJB.

Sept. 11 through Sept. 17 is 1.05 inches for Bend, which is 50% of the MJB.

Sept. 4 through Sept. 10 is 1.14 inches for Bend, which is 54% of the MJB.

August 28 through Sept. 3 is 1.26 inches for Bend, which is 60% of the MJB.

August 21 through August 27 is 1.41 inches for Bend, which is 67% of the MJB.

August 14 through August 20 is 1.41 inches for Bend, which is 67% of the MJB.

July 31 through August 6 is 1.76 inches for Bend, which is 84% of the MJB.

July 24 through July 30 is 1.78 inches for Bend, which is 85% of the MJB.

July 17 through July 23rd
Looking at the forecast for this week and the highly varied weather for last week, I decided to use only the last 4 days to set the percentage for this week. doing that gives 77%.

July 10 through July 16 is 1.49 inches for Bend, which is 71% of the MJB — a pretty good sized drop from the previous week due to the cooler and cloudy weather we have been having!

By the way, this is a good time to start trying out this process!  If your garden went through the week before last without getting too dried out, then whatever watering times you were using that week would probably work as the MJB settings in your system. So… set those times as your baseline (normal) run times. You can then use the % feature on your controller to enter the weekly percent of MJB that you find here…

July 3 through July 9 is 1.98 inches for Bend, which is 94% of the MJB.

An observation from my garden: as my perennials grow in and take up space, not as much water is getting to the ground for them. I remeasured a couple of areas and found that I needed to increase the watering time. Also, I bumped the “plant need” factor from .8 to 1 in the areas where I have planted in the last week or so and will keep it there for another couple of weeks…

June 26 through July 2 is 1.68 inches for Bend, which is 80% of the MJB.

June 19 through June 25 is 1.82 inches for Bend, which is 87% of the MJB.

June 12 through June 18 is 1.53 inches for Bend, which is 73% of the MJB.

June 5 through June 11 is 1.3 inches for Bend, which is 62% of the MJB.

May 29 through June4 is 1.16 inches for Bend, which is 55% of the MJB.

May 22 through May 28 is 1.06 inches for Bend, which is 50% of the MJB.

May 8 through May14 is 1.14 inches for Bend, which is 54% of the MJB.

May 2nd:  The total ET for the last 7 days is .94 inches for Bend, which is 45% of the MJB.