Starting perennials or biennials in the autumn

Mignon dahlias are great. Flower all summer long, still going now, just need to keep nipping off the dead heads. Don't need any support either. There are some short heleniums which won't be affected much by wind or rain, Short 'n' Sassy is one we have. Some crocus/other spring bulbs and aubrieta for some colour early in the year perhaps.