A couple of points: I got enough seed for about an acre or so, it comes in a fairly heavy box. I would recommend getting the hand seed-spreader as getting even coverage by hand is tough, and yard spreaders don't seem to like the mixed shapes of the seeds. Use a landscape rake after sowing or the birds will devastate your seeds if sitting on the surface. Many wildflower seeds do prefer being very close to the surface, so a little raking will do. Get the mixes for your region. It will contain both annuals and perennials. It will also give you the best chances of finding a plant that really likes your local conditions. For example I thought Lupins would be nice, but they simply HATE my soil type. Too basic for them. Instead Indian Carpets, Bachelor Buttons, Cone flowers (black-eyed Suzanns), and cosmos thrive. If wanting to prevent erosion, wildflowers probably are not your best bet, but better than nothing. They do NOT form dense root systems or vegetation like grass and some ground covers. If you need to stop erosion, grass is king.
In my case, I wanted the dang flowers. The local flower shop will be visiting next summer in return for a few free arrangements.
