I have tried and tried to get wildflowers established, with no luck. Twice I've scattered 'western mix' seed on bare dirt. Other times I've tried to overseed on pasture grass. I'm fairly certain my problem is I don't adequately water it the first year. I don't see any bare dirt in my immediate future but would still like to try for wildflowers on my back hillside. My next thought is to gather seed of plants that self-sow in my gardens and toss them out this fall. My candidates so far are: various colors of California poppy, red field poppies, calendula, toadflax, borage, and feverfew. What else is a free self-sower in your beds, that may (or may not) grow with little to no attention.
I have used this mix from Eden Brothers and I do have some success with seedlings growing way out back. Of course more warm days and sunny skies might help the situation to achieve some blooms. I have extra seed from this PNW mix. Your welcome to it . Let me know and I can send it to you. http://www.edenbrothers.com/store/pnw_wildflower_seed_mix.html
Good ideas, I gathered seed from wild foxglove last season and will do so again. Also from my columbine, although I think they don't come true do they? I seem to get a bunch of the old fashioned 'granny bonnet' types popping up that I know I didn't buy. They are jolly though, I'll grab some seed from them. My sister has rose campion, I'll see if she can nab some seed for me.
Strangely, I've tried transplanting peach leave bluebells in my wild area, which I thought were indestructible, but they have not thrived. Maybe direct seeding them would be better.
The difficult part is I have to plant over existing pasture grass. We do have a healthy mole population, though, and I can spread out their mounds to give the seed a fighting chance.
Yarrow is a good candidate also. I always find it to be full of grass in my garden, so perhaps planting it in the grass will work well. Here's my favorite, Paprika, which I lost this year to slugs or something. Fortunately I gave a division to my sister a few years back and can reclaim some from her this fall.