depends...

if u did 1 year of round-up, then just keep dumping seed on it.

but if ur soil prep sux, then round it up for a year and plant in the fall.

fyi, make sure u got some good seed and a proper seed mix for ur soil/area.

froggy

I could advise you on this but would need lots more information. My best advice would be for you to call one of the many reputable native plant nurseries. Most of them have toll-free numbers. I would caution anyone against purchasing a "wildflower" mix which you may find in traditional nurseries or discount stores. They often contain weedy eurasian species like Queen Anne's Lace which may take over you planting. Native prairies and meadows take some time to establish but they continue to improve each year.

second to what wiscobill says...
your plants need time - it takes a couple years.
advice on what to do next depends upon how your site was prepared and what kind of wildflower mix was planted...
you do need to keep anthing from going to seed. a common recommendation no matter what would be to mow the area keeping all plants around 6" or less for the first year.

Thanks for the advice. I don't know what seed mix the landscaper put down, but most of that got washed away with the rains. About 3 weeks after that, I raked parts of it over and spread the "dry site, short prairie mix" from Ion Exchange in Harpers Ferry, IA. It includes

Wildflowers Anise Hyssop, Black-eyed Susan, Brown-eyed Susan, Butterfly Milkweed, Canada Milkvetch, Columbine, Dotted Mint, Evening Primrose, Golden Alexanders, Heartleaf Alexanders, Hoary Vervain, Lanceleaf Coreopsis, Large-flowered Beardtongue, Leadplant, Narrow Purple Coneflower, Ohio Spiderwort, Old Field Goldenrod, Ox-eye Sunflower, Pale Purple Coneflower, Partridge Pea Prairie Alumroot, Prairie Cinquefoil, Prairie Wild Rose, Purple Prairie Clover, Rattlesnake Master, Rosinweed, Rough Blazingstar, Roundheaded Bushclover, Royal Catchfly, Showy Goldenrod, Stiff Goldenrod, Upland White Aster, White Prairie Clover, Wild Bergamot, Wild Lupine, Yellow Coneflower
Grasses Little Bluestem, Sideoats Grama

Now the area is mostly grass (the short lawn kind) and some taller grasses. There are about a dozen poppies, some small white flowers that look like forget me nots, and some that look like a purple clover. I do plan on having it mowed down in autumn, but should I reseed then as well? Sorry I am not better with the digital camera to give you a look.

Thanks again!

i probably would wait - they are slow growers... particularly the first year they are primarily establishing roots. if by next fall you still do not have anything, then you might want to reseed. if you are anxious for some flowers sooner - you might want to try a few plugs next spring...they flower sooner than plants from seed. the other thing about plugs - for us non-plant people - they help you to identify those same plants as seedlings when they do come up.

Thanks, Joepyeweed (by the way, great name). I think what you say makes sense. I especially like the idea of knowing what everything is, because, to be honest, one germinating plant looks like any other to me. I have pulled some out that I thought were weeds, since I say them in my mulch all over my property, but I wouldn't be surprised if I pulled out some "desirable" plants, too. Thanks again!

one more thing, you may not want to wait until fall to mow. you may want to mow now - to keep things from going to seed this year. then mow again in the fall. i have the same problems with seedlings - hard to tell - thats pretty common.