By Masie
United Kingdom 
Hello again everyone! Instead of vermiculite can I use polystyrene balls from an old lap tray bag in my soil/compost or not? it's a shame to throw it all away. thanks, masie.
2 Jun, 2011
Answers
Just remember that they don't absorb water, nutrients, or air, so they will lighten up the soil, but won't do much in the way of improving the structure.
3 Jun, 2011
They will add nothing to your garden what so ever and will stick together at some point and you may regret it, why not take them to your recycling centre?
3 Jun, 2011
They're certainly no substitute for vermiculite or perlite, that's for sure - at best, as Tugbrethil says, they're light and can pad out compost, are inert, don't hold water, but they do tend to flocculate or aggregate, so I'd recycle them as Drc suggests.
3 Jun, 2011
Hello Masie:)
I don't see why not....they'd add to the drainage and be cheaper than vermiculite! Let us know how you get on with it...we'll all be out buying lap trays if it works :))
2 Jun, 2011