By Gezza
United Kingdom 
I inherited a brick built woodshed, a bit damp, which had about 4" of bits of bark, leaves etc on the floor. This has now turned to a mid-brown, crumbly substance resembling very fine tilth soil.
I'm in the process of removing it and have already filled 4 rubble sacks. Can I use it as mulch and potting compost, please?
Geraldine
11 Jun, 2013
Answers
Many thanks, Bulbaholic, I'll certainly try your suggestion.
Gezza
12 Jun, 2013
Theoretically, the material should be wonderful for potting compost. However it has obviously built up for many years and you don't know what else has gone on in the shed before you inherited it.
You could try the 'Cress Test': fill a small plant pot with the material and sow a quick-to-germinate seed, like cress or lettuce, on the surface. Put the pot in a clear polythene bag fastened so that there is plenty of growing room above the pot then watch what happens to the seedings. If they germinate and start to grow healthily then the material is probably OK to use but if they wilt and die then there is a problem and it would not be advisable to use it.
It will not have a lot of nutriment in it so you should add some bonemeal or other fertiliser of choice
11 Jun, 2013