Hi Carole. In my experience, yes, but see what others say. :)

Generally tiny seeds need to be planted shallowly so if you do put bark on bear that in mind.

I would think some will, some won't. Something like Borage will come up anywhere, but I find poppies are really erratic. I suppose big, strong, tough plants will come through and delicate little ones won't. Just choose carefully :)

It does depend what you want to grow. Wild flower 'mixes' are unreliable, but Ox-Eye Daisies will grow anywhere, and Corncockle is easily germinated too. Good luck!