The backyard of our new dwelling (a 1910 duplex) apparently hasn't been touched in at least 10 years. No plants, very few weeds, a large plum tree trunk with no limbs standing in the middle like a Dryad de Milo.

Anyway, I've got the soil amendments and the design/plant inventory worked out. What is perplexing to me is the layer of plastic mesh that exists under the first 1/2" to 1" of the soil. The strips are light blue in color and about 10' long and 1' wide; the holes in the mesh are about 2" square. In some areas I've been able to pull it right out of the ground in long strips. I'm going to have to gently rake and pull the rest out over the next couple of weeks.

Might anyone know what this stuff is and why it's there? It doesn't seem likely that it's a hazardous soil indicator, so perhaps it was a misguided attempt at erosion control?