Shade gardens can be glorious and to make full use of the shade you garden offers you must first understand shade itself.
Light or Dappled shade, is bright enough that most plants will grow there, even those that claim to need full sun. In this case, the sunlight moves across the garden and never stays in one place for long.
Open shade may be found in that small space beside your garage or shed that has a northern exposure. The light there is bright but it rarely receives any direct sun.
Medium shade this is the drawing line between plants that will accept shade and those that do not. Usually found under small trees or near decks and stairwells, for example.
Deep shade allows no obvious sunlight to enter where trees, fences and buildings block the view. This is the home of some ivies and mosses.