Once your have mapped out your new sprinkler system and staked your yard with the locations, the task then becomes digging the trenches for the pipes. Start with the one that will connect to the control valves, making it and all subsequent trenches as straight as you can.

Trenches need only be 8–12 inches deep in mild climates, In areas where hard freezes occur, 18 inches is sufficient. If you live in a very cold climate, consult with your irrigation supplier for the recommended depth below the frost line.

Because digging is arduous work, study your plan one last time for missed efficiencies such as using a single trench for more than one pipe. A pick and shovel are all you’ll need; however, depending upon the extent of your project, you may choose to rent a trenching machine (though this is not an option for flower beds or areas with ground cover because it will destroy the plantings). Water the ground a few days ahead of time to soften it.

Before digging, place plastic sheeting to both sides of each trench you plan to dig. Preserve the sod by gently working the shovel underneath it, peeling it away, and placing it on one of the plastic sheets. Similarly, salvage the soil by placing it on the plastic sheet on the other side. By doing this, replacing both soil and sod becomes a much easier task after you’ve laid the pipe.

If you want to lighten your load even more, you can hire a pipe puller to install the pipes. Using a pipe-pulling machine is not a job for the uninitiated, so do not consider renting one and doing it yourself unless you have had prior experience.