They have all come back themselves i left the seed heads on and they scattered themselves..I have hardly touched it to be honest except grab some chickweed out of it in february..they are still coming through i still have the loosestrifes,marshmallow.willowherbs,and a few other bits and bobs to flower.. if i was staying here i would thin it out a bit but i shall be moving next spring so i have just left it to self seed and spread..its a bit dense in places..
i have wildflowers in all my borders mixed in with herbs..i wont be doing that again as i have to walk through wildflowers to get at my herbs so i shall seperate them in my next garden..
I suppose the birds have eaten some of the seeds as last year i had a lot of field poppys and they havnt come back its just so dense i reckon only the strong are pushing their way through..