Timers need to be removed from the pedestals (carefully) and drained for winter storage. The batteries need to be removed and discarded – fresh ones will be put in next year – don’t leave the batteries installed over the winter. Once drained, they can be stored in a box in the shed, and the garden will lock them up for the winter.
When the timer is taken off, leave it off for at least 10 minutes to drain the pipes/tubing before covering the inlet coupling. We will later blow the water out of the system.
Take a couple small plastic bags (baggies) and several rubber bands and cover the inlet coupler that was connected to the outlet of the timer to keep dirt and guck from getting there and clogging your emitters next year when the water is applied and pushes any crap accumulated inside the pipe down to the emitters.
Drip lines will need to be blown out, or otherwise have the water drained from them. (In 2010, that was done for all lines by Bruce Bacon.)