I started demolishing an old brick walkway in my backyard and I found sand underneath about a good 3 inches worth of sand. My question is: If I leave the sand underneath and add about 2 inches of topsoil over the sand, will my grass grow on this top soil sitting on top of sand? Is it a bad idea to leave the sand down there? Should I remove it?
2 Answers
Just put the topsoil over the sand and seed it. The earthworms, and other dirt fauna will eventually mix it together.
It wouldn't hurt to mix it yourself perhaps with a hoe, but it's not really necessary.
I'd recommend removal - a little bit mixed in with soil is fine, but 2 inches of topsoil over 3 inches of sand means, although your grass will grow okay, if its a high traffic area, it won't be 'stable', meaning it'll slip and slide about a bit, so won't remain level and even. If, though, it's not a high traffic area and the only walking across it will be you with a mower occasionally, it'll probably be okay. As its an old path, the risk of salts in the sand will be minimal.