Cleaning up the garden in the fall can be a bit confusing, especially when it comes to cutting back perennials. Should you leave them alone or cut them back as soon as they fade? The answer, of course, depends on the plant. - Gardening Take
This is a great photo of what your hostas look like when just coming up. They can be quite the last thing to come back each spring so don't give up on them. This links to an article on: Dividing Hostas Like A Pro - How & When To Divide Your Hosta Plants
Tips on Dividing Perennial Plants~ Quote: Keep this handy! There is a wealth of information here about dividing perennials! Also a list of best times to divide them. Definitely the best, clearest instructions I've seen (from Fine Gardening)
Ornamental Grass Care - Cutting, Dividing And Planting - OWG
If you haven't cut back you Ornamental Grasses now is the time, as well as dividing. Cut the grasses back to about from the ground. I use a nice sharp Garden Spade to divide and separate. Dividing should be done every two to three years.