This happens a lot at activation.

Most of the time, it is a electric valve issue.  The electric valves are generally in a green box in the ground.  The electric valves have solenoids and or bleed screws that are difficult to close properly during the winterizing process –  they are plastic parts that easily wear out.

Basically it is impossible to know if all the valves are closed after the winterizing process –  as the water is no longer on to the sprinkler system.  

If you look in the green box, and there is water coming out of a part on the electric valve, we suggest trying to gently tighten the part. If unsuccessful, a service call is likely needed.

Dry patches can be due to a number of things, such as too short of run time / water on a given area, initial design deficiencies or a maturing landscape now blocking sprinklers.

Lots of recommendations can be put forth to make affordable improvements. 

We specialize in irrigation, so we are prepared to fix these challenges.  

Our service vans are stocked with over 625+ unique parts for maintaining irrigation systems.