In article ,
Martin Brown wrote:

What can I do with the old, depleted soil from various pots and
containers?
The soil is compacted with roots, so it's more or less one big hard ball.

It will not be good in a compost bin

Can you tell me why that is Nick?

Because it will contain a high proportion of inert or nearly inert
material. Compost bins, even more than heaps, work better when the
majority of the material is decomposable (i.e. food for the bacteria
etc.)

Having said that in small amounts compared to the volume of everything
else it does no real harm or if a lot of it is soilless compost then it
doesn't matter so much. Too much real soil will keep the air out.

It depends on your soil! It can also produce a dry chunk.

Knocking out any loose soil from rootballs somewhere that needs either
better drainage (gritty stuff) or more peat (soiless) and then
composting the roots works pretty well.

That is what I do. I would tend to avoid even that in a bin, as
roots are woody or semi-woody and are better suited to a cold heap
than a (usually) hot bin. I run a cold heap and so just chuck them
on. People with a bin may want to make a separate heap or put them
in a plastic bag (with holes, and dampened).


Regards,
Nick Maclaren.