Virtually all cultivated peppers are C.annuum, and I've had a lot of success growing these from seed. (I also usually buy 3-4 plants locally each year but selection is usually very limited)
I soak my seeds using a salt petre solution before sowing. This is recommended particularly for those that are harder to germinate (eg. chiltepins). Here in North Texas I usually get a small crop before the height of summer, and then the main crop September-November. All are grown outside, full afternoon sun. I used to use containers a lot, but I'm finding raised beds produce much bigger plants - probably due to water and root space.
Anyway, this is the second year that I have tried to grow C.frutescens varieties. Last year I tried Tabasco and Twilight. This year just Tabasco. Both years I've had poor germination rates (5 out 50 seeds this year). Plants never grew very big last year. This year they are definitely a lot smaller than the Anchos and Gypsies which were sown on the same day.
How can I improve their growth (with a view to more fruit in Autumn), and how can I improve the germination rate?