Locating Capped-off Sprinkler heads

Me and the missus-to-be moved into a brand new house about a year ago. Said house came equipped with a sprinkler system for the yard. Now, being the environmentally conscious couple that we are, we decided to re-do the back yard. “Out” goes most of the water-thirsty grass and “in” goes a lot of drought-tolerant native plants (and 12 cubic yards of mulch, but that’s a different thread.)

Now I want to convert my mostly useless sprinkler system into drip irrigation so I can direct water exactly to the plants that need it. This will require re-purposing some of the sprinkler heads, but a lot of them won’t be needed and I want to cap them off a couple of inches below the surface.

But – and this is the crux of my problem – I want to be able to find those capped-off heads later without having to dig a lot of holes and hoping to get lucky.

So far the solution I’ve come with involves gluing either a rare-earth magnet or a stainless steel nut inside each of the caps, the idea being that later I (or future owners) could come back with a metal detector and locate them. Will this work? Will a metal detector detect magnets? Will strong magnets like that be any easier to find than plain steel nuts? Is there a better way to make these hidden-but-findable that I haven’t thought of yet?

My brother marked his sprinkler heads with metal. His problem was that using a metal detector he found every coin, screw, bottle cap, etc that was in his yard.

I think I’d just run an extra large galvanized steel nail alongside the pipe. You could wire it to the pipe/cap if you like but that’s probably not necessary. They’re easily found at any hardware store. Something that big should positively scream on a detector.

12 yards of mulch? I thought my 4 were a load to spread. Poor you.

I think the ferrous metal next to the capped head is the most elegant way to go.

I thought (briefly) about suggesting dowsing…

My only other solution–and this is the one I did because I was too cheap for a metal detector–would be a scale drawing. When I re-did my previous backyard, it just happened to work out that the previous owners had conveniently placed each sprinkler head very near an obvious landmark so I could just note that there was one “one foot south of the right angle bend in the wall,” there was another “two feet west of the pillar,” etc.

My thoughts ran immediately to lieu’s suggestion of a large nail pushed into the ground next to the riser stub. Combine that with a map of the yard created with some free or inexpensive landscaping software and you should be fine.

Bonus use for the landscaping software is that you can actually play with landscaping ideas. :wink:

Oh, the plan’s all made; all that’s left is the implementation.

Obviously you’re new to this whole landscaping thing.

You’ll never be done. I’m acquainted with several families that rearrage their yard more often than their living rooms.