There are two types of chamomile, annual and perennial, and they have different requirements. Which do you have?
Likewise the columbines (aquilegia) - wild type columbine seed needs to be cold stratified or preferably planted outdoors in fall to overwinter and sprout in the spring. Commercial hybrid types may be able to just be planted. Which do you have?
Lilies are rarely started from seed, so I wouldn't know anything about that.
Nigella should be planted outdoors now (presuming you are past all danger of frost)
Nigella does not like being transplanted and does best if direct seeded outdoors. Seed can be sown from early spring, throughout the summer and even in fall, in climates with mild winters. Choose a site that gets either full sun or at least morning sun. Nigella is not particular about soil quality, but it doesn't like to remain wet.
To sow, simply scatter the seed and rake it in. You don't really need to cover the seed with soil, but it does need to be pressed down slightly.
Maintenance: Nigella is a short lived plant and probably won't make through an entire growing season. For a continuous bloom, repeat sow every 4 weeks. Once your plants have begun to scatter seed, you won't need to continue sowing.
https://gardening.about.com/od/plantprof ... igella.htm