soulman writes

The soil came from a skip that had been excavated from a garden, some of it
still had grass roots so I don't think is subsoil.(although not sure what
garden!). The thing is when I went to a few garden places the top soil was
nothing like normal topsoil, it seemed to be more like a finer manufactured
compost? would this be as nutritional? or will any compost be good enough to
bulk out what I have? I did add some general purpose fertilizer.

sorry for the questions, google is a world of info, but there's also aload
of shite! not quite as good as experiances of real people

A high humus content is usually a good thing (better water retention in
summer without being too soggy in winter), and the effect of humus is
usually to make the soil darker in colour. However, if you add humus to
a clayey soil, you end up with a good rich soil (this is all very
non-scientific).

Be prepared to continue improving your soil by adding humus (home
produced compost for example) each year.
--
Kay