Mulch might smother or prevent germination of any wildflower seeds. I know I have much better volunteer activity in years I don't mulch. It also helps to remove fallen or spent leaves. However, if you don't mulch you might have more non desirable weed seedlings. Choose your battle.

Martha

What docmom said. A lot of wildflowers need sunlight to germinate.
Renee

Agreed with docmom also.
kay

Some seeds need cold temps to germinate, and some warmer so you never know what is ready to come up. Also, if you are using pre-emergent on your lawn (especially mixed with fertilizer) some might leach in to the beds. Other than that who knows. I get very little re-seeding in many of my beds.

Texas & Oklahoma Wildflowers prefer Alkaline or Neutral soil.
Some wildflowers need host plants, like the Indian Paintbrush. It grows where there are native grasses and has a symbiotic relationship with them.

In the Fall, collect 'some' of your seeds and sow them where you want them before the wild birds eat them all. Leave some for the birds, though, because Wildflower Seeds are their natural food.

Also, some wildflowers prefer hot, dry locations and some like shady moist places. They may all germinate, but some may not grow well if the soil, light, and moisture levels are not to their liking.

I also agree with what everyone else posted above.

~Annie

I think the only flower I've ever had to reseed was zinnias, but I mulch heavily. I know you asked about wildflowers though.

Thanks, everyone, appreciate the information! I think I will just battle the weeds and see what happens! This has been fun to watch, but a little puzzling as the landscape soil that was brought in is from either West or East Texas, and many of the weeds I am not familiar with. Guess I'll find out soon enough!