There must be differences between various species and seeds provenience, but all Roscoea I've done from seeds, would qualify as warm germinators or requiring about 1 month of cold (auriculata, alpina, scillifolia, tibetica, schneideriana...).
I notice that most would germinate better after the 1 month cold so I sow usually somewhere in January, and by end of February they come under lights indoors. This works well in our climate; outside they would germinate in late May probably and get a shorter growing season.
I will look for few seedlings images.
Images showing Roscoea seedlings size in March/April.
