permaculture

["Rene and Lorraine van Raders" <rvraders@tpgi.com.au>]

Don't know if this is much use to you, but in Australia we can get high
density polyethylene squares (Gras-Cel Turf Paving Blocks) that are about
the same cost as laying cement.
 The hexagonal sections are designed for heavy vehicles (of the type you
mention that allows turf to grow through), usually on a compacted sand base
(as for cement) .  I don't have any personal experience.. just saw them at
a conference I attended.  Contact Total Erosion and Pollution Control
(Aust) Co, 35 Parraweena Rd, Caringbah, NSW 2229, (02) 9524 0155.

Cheers Rene