By Kathyogden
United Kingdom 
Can anyone tell me if it is safe to use wood ash from a woodburner as potash for my garden? Also I have a half tonne bag of clean vermiculite that came out of a chimney that had a liner in it. Can I use this to put in the bottom of my deep veg beds to help open my heavy clay soil? Thanks in anticipation.
4 Jul, 2012
Answers
I've also heard that you shouldn't use it if you have lit the fire with firelighters - as opposed to newspaper & kindling. Don't know about the vermiculite - can't quite picture how it is clean if it's come out of a chimney? No contamination at all?
5 Jul, 2012
You can use the wood ash but only if its wood and no coke, and use it sparingly as it tends to make the ground more alkaline. You need to keep it dry until you want to use it as the potash washes out in the rain.
4 Jul, 2012