Posted: 29/06/2014 at 21:50
I lke to sow when the plants shed seed. When you're buying seed this depends on the seed company selling fresh seed.
Lots of info on this site but not all seeds are covered. I would sow hostas when ripe and leave cold over winter. Cold frame or cold GH is good. I used to leave them all outside but everything seems so much wetter no sow I have them under cover. well drained compost and cover with grit.
Germination mostly happens in spring though sometimes it's very quick when seed is fresh
Chiltern are good and Plant World. Also Derry Watkins who does a fresh seed list