Well, I just seeded some Lychnis this afternoon. The Stokes seed package says that Aug 21 is the time to seed it. Also, if you see all the Rudbeckia popping up every year, all that seed got started the previous fall. In fact, there must be lots more species that want to germ in the fall. I just can't think of anymore right now.
But think of the fun you can have if you start seeds indoors next spring. Start planning now and get your seeds by Jan 1.

Hum, Lychnis... I have never heard of that. I'll have to look it up. I wish I had the patience to start and tend little sprouts indoors, but I know the tender things will suffer from my late Winter neglect. I had been thinking of seeing if Delphiniums would work sown outside in the Fall, but gave in today and ordered three plants with a credit I had a one of the online shops. I *think* I have some False Indigo seeds from a shrub I pasted walking around the neighborhood recently. And I have a pile of Purple Pasque Flower seeds from my own garden. I'll try both of those this Fall, I think.

Any thing else?

Hi Elinni. You might want to check out the GW Winter Sowing forum. It's the simplest way to start perennials for next year. Very little work and very little patience needed. Several people here on the MN forum do it and will probably chime in. Read the FAQ at the Winter Sowing forum then ask questions, either there or here. I've done it myself and it works great!