I live about 30 miles inland from the San Francisco Bay. I replaced the grass in the front yard with drought resistant plants and mulch. The lawn in our small backyard really looked bad from years of drought and my mismanagement. With all the rain we had I finally have the lawn in the backyard looking decent, plus currently am watering A LOT. I spread grass seed in some areas which is growing well.

I have an in ground automatic Rain Bird Irritrol sprinkler system. The lawn is a zoysia fescue mix. Now that the lawn is decent how long, how often, when, should I run the sprinklers?

 

How frequently are you currently watering? "A LOT" isn't very specific.

I don't know your climate but I think you could back off to doing one good long soaking a week. Your controller might allow you to break that one watering into two or three separate events separated by some time to allow it to soak in. Generally you want infrequent but deep waterings that force the grass to grow deep roots which can better withstand summer heat and drought.

 

I agree with Dane - 1-2" of water per week is the norm with you supplementing whatever portion of this amount the rain does not supply. Long, deep waterings encourage root growth whereas frequent light waterings do not.

 

Put out some empty cat food/tuna cans..... and see how much water goes in per cycle.

 

30 miles east of SF is probably the Pleasanton/Dublin/Livermore area (used to live there) and in the summer it is HOT. But in the evenings with the ocean breeze it cools off to the point that a blanket is needed.

Definitely will need a little more water than once a week but clearly watering at night is the key, you wont loose much to evaporation which will cut down on the water usage.

I cant recall watering schedules but starting every 3 days with a good watering would be the starting point and adjust as needed! Your new seed will need to be covered with straw to hold that moisture in.

 

Also....dig a wedge down 6 inches with a pointy shovel and pull out.... to see when soil goes from wet to dry.