Question
I live in Sacramento, CA and am in the planning stages of landscaping my completely bare backyard. I'm contracting someone to pour concrete and install drainage and irrigation. I will be prepping the yard and later installing the sod and plants. My questions is:

Prior to having the irrigation system installed (and having the concrete poured), what prep work do I need to do? The backyard is currently dirt/mud (and weeds). The concrete contractor will be laying a base and doing some mild grading. I will kill/pull the weeds. Do I need to rototill the entire backyard or just the area of the future lawn? When should this be done? If I do the landscaping in phases, will I need to lay down a new top soil mixture and rototill again, prior to planting the sod? If wait to plant the grass and rototill later, do I run the risk of breaking my irrigation lines?

THANKS!!!

Answer
PJ?br>


[ Prior to having the irrigation system installed (and having the concrete
poured), what prep work do I need to do? ]
None, except to have laid out the location of both beds and lawn.  
Anything else will just get messed up by the workers and equipment and will slow them down.   Even if it's just with stakes and string, make it clean where beds and lawn will eventually be.  This is necessary for them to create the proper layout of stations and heads.

[future lawn? ]
I'd till just the lawn area and only right before you're ready to seed or sod.
Add soil at that point if you need to fill holes, or raise the overall level a little.  If you just want to improve the composition of the soil before planting, cover the area with an inch or two of compost and till that in. Rake smooth, and then lightly roll the area, and you're good to go.

[risk of breaking my irrigation lines?]
If the system is put in properly, the lines will be deep enough that they won't be a problem.  You'll need to mark the irrigation heads, though.  That's what usually gets broken off.  Good contractors will provide an "as built" plan of your system, showing you the location of lines, valves,heads and controls.  This can help avoid problems when you are doing the big planting...trees & shrubs.


For what it's worth,
Mark in Porltand