Winterizing Sprinkler Systems

Never had one... Maybe cover the sprinkler heads against freezing? Protect any exposed piping (like from the tap to the beginning of the system), for sure. Other than that, I dono.

Making sure there's no water in the system would be a good start.

Is the system above or below ground?

They blow them dry or mostly dry with compressed air, BD.

Depending on the system. It should definitely be drained of all water. The system can be blown out with compressed air, however the manufactures instructions should be followed as it would depend on the size of the pipe and psi being used from the compressor to ensure that no damage is done to the pipes etc.

Don't know if it is the proper way but you could add anti-freeze like the car windshield fluids. They can be good to -40 deg. F or C.

Then what? Shoot the anti freeze into the grass come time for watering? How do you propose to add the anti-freeze into the system?

Sorry, but not a good alternative to proper maintenance.

I don't think that the pressure is allowed to build up on these flushes, Intrepid, though I may be wrong. As I understand it the compressed air can be at any PSI because the system is not closed but open.

I've also heard that it isn't necessary to remove all the water, nor is it likely that that would happen. A small amount of water that freezes, cannot exert the pressure necessary to rupture the line.