They germinate erratically, and the seedlings are tiny to start with. They need to be sown on the surface of fine compost because the seeds are so small, and the surface needs to be kept lightly moist, This can lead to green algal growth, so it is best to use fine vermiculite, which is inert, rather than ordinary compost. This reduces algal growth.
Ideally they should be winter chilled, so I have sown them in pots in winter and covered them with a tile to stop predating mice etc., and then lifted the tile off in February and brought them into a cold greenhouse to germinate, spraying occasionally with water from a hand sprayer.
I have also left them outside over winter with a covering polythen bag held upright with wire hoops.
Leave them to get to manageable size before pricking them out. .