Lupins - delphiniums are what I have sow the most recently, I tryed some bergenia - primulas - polythanus as well. All the other plants are biennials like foxgloves - wallfowers - mysostis - sweet W - winter pansys
You can sow almost anything now holliehock, however, it will take months for them to grow sufficient root systems to plant them out and survive the winter. I have sowed lupin, sweet william, coreopsis and a few others, but most won't be planted out till spring unless I can get them up to scratch by September. Some years I'm lucky and get them in, other times they have to wait till spring. It does depend on weather and good growing on techniques. I do have space which is an advantage as overwintering young plants can be problematic. If you aren't in a hurry and don't mind losing a few plants it is fun, economical and gratifying raising your own plants. Even if you have a disaster what's the price of a packet of seed and some compost.