Evening primrose seed trills the Goldfinch

We have a patch of garden 20x12 that is, lets say wild. its never  mown. Each year i bring back whatever wild flower deed i find, and simply throw it onto our wild garden. It takes a strong seed to compete with grass. 
Over the years it has developed well
We noticed a few year ago that evening primrose set seed where ever it landed ,so one autumn i pulled a seed head up, and threw it onto the wild garden. There it lay all winter. Spring came and evening primrose grew. We left the seed heads for this years goldfinch. Saves a fortune on sunflower seed and being  plagued by rats