Question
what perennials will do well in a shady location and when is it best to plant these or any perennials?

Answer
NOW is the best time to plant any plants.

First though you MUST prepare your soil.  It may be pains-taking but you will see such better results from your garden, sun or shade.

You didn't say where you live but this is my formula and I have good topsoil for about 2-3" but then a lot of clay.
for every 6' x 6'sq. area:
  1 bag peat (If you get the very large 3.cu.ft bags-only
    1/2)
  1 bag sand-play sand
  1 bag gypsum
  1/3 bad Millorganite (an organic fertilizer found at    
     Nurseries--and I SWEAR by it for flower beds and       lawns, for lawns, put it on heavy like any fertilizer
     in spring and fall!)
  1 bag cedar or dypress mulch-this gets tilled into the
     soil with all the other stuff.

Roto-til or turn into soil with shovel-at least 5"-6" in depth-more if possible, before planting.  You will be AMAZED!!


Then and only then are you ready to plant.


Even though these plants say they are for only sunny areas-I have had good luck with these in shadier areas.

Not even a question about the spring flowering:

Partial sun and shade-Spring:
Crocus
Grape hyacinth
Coral Bells-green leafed
Candytuft
Spiderwort
mints-keep cut to a manageable area
Lilies of the Valley-these will spread-start out sparingly
Elephant ears-green or black-these are HUGE and need to be
  dug out for winter and stored properly.
Caladium-Very colorful and need to be dug out for
  winter and stored properly.



And on into summer flowering:
Coral Bells-red leafed
hosta-and they do flower! there are now 228 different
  varieties--Magnificent!! Look on web for varieties.
Lady's Mantle
Lungwort
Mountain bluebells
Cranesbills
Summer phlox (the tall ones)
Bee balm (spreads wildly)
Purple sage

You may want to go to your library or book store for books on shade gardening.
Go get your hands dirty!!

Sijka