Self sown annuals

Bane or blessing?  Self sowing annuals, and perennials too, are one of the best things about a cottage garden.  They save money and energy and time, our three resources in all life's endeavors.  Currently in my garden there are new little foxgloves, forget me nots, alyssum, coreopsis, columbine, hellebores, violets, Johnny jumps ups, larkspur, verbena bonariensis, poppies, California poppies, nigella, and probably more.  So many new little plants all for free, with no work involved.  Perhaps the best part is the anticipation, of watching for seedlings then looking forward to the bloom. 
But this year, the nigella is the bane of my spring gardening. Allowed too much freedom, any of these self seeding plants can become a weeding nightmare as they come up in carpets, or come up everywhere, leaving one to wonder how in the world they can spread seed so far and wide.  Nigella is an annual I grow primarily for the seed pods, thus seeds everywhere. So I pull and pull and pull and hoe and hoe and hoe, thinning them down to the few plants I actually want.  In other areas Jerry does the same with the California poppies.  The various reseeders take their turns at over reproducing.  Most are easy enough to remove, but their populations ebb and flow depending on just how much effort I put into removing them the year before.  This year nigella is annoying so I am pulling all but one or two, therefore next year there will be far fewer little blue flowers caught in their netting, and fewer seed pods.  A few years from now I may think oh how I miss the nigella and sprinkle more seed deliberately.  And so the garden changes from year to year.