Thanks for comments lads, I was worried it was a tad overdone but after looking at some photos in Rails Through the West I see that some freight sidings got in a far worse state!
@Glenderg - yes it needs variety, I have a static grass applicator on order so it's likely to get more overgrown! Once the "natural" debris is done I'll start in on the real rubbish!
But it will have to wait a while, I had my tonsils out Monday. So I'm sitting here at the PC feeling sorry for myself...