An inch might be too much for flower seeds. Most flower seed is very small and probably wouldn't emerge from more than 1/4 inch. If you time it right it should be okay. So put the compost down before the flowers go to seed but after your seedlings have established.

I agree with GJ than an inch is probably a little too much, but I think it also depends on what kind of self-seeders you're talking about, and whether or not it's something that drops LOTS of seeds. If it really is something with "enough" seeds, you could possibly spread your compost and then rake it really well, which "should" bring at least some of the seeds close enough to the surface for them to germinate. But the only way to know for sure would be to try it somewhere to see what happens. Otherwise I agree with the suggestion to wait till they're growing this year, after the plants are established but before they start going to seed, and then let this year's seed crop drop on the compost after you put it down. One more possibility, for this summer, not this spring, would be to plan to go around and collect some of the seed from each different type of plant, then you could spread whatever you wanted to next winter/spring, and sprinkle the collected seed around after you're done to assure that you'll have seed close enough to the surface to germinate.

Skybird

Thought about raking it in in late Fall, agree it's kinda iffy. I'll probably end up trying a little of that, just to see what happens, and a lot of seed collecting.

Thx all
Bob