One of the things I've been trying to figure out is what parts of my yard might be considered part shade, and what parts full shade. Found a good suggestion in a book I recently purchased. Before making a decisions about what to plant and where, he suggests planting petunias in different spots. Where the petunias bloom heavily can be considered full sun. Where they bloom OK but not heavily, is partial sun, and where they bloom very sparsely or not at all, is full shade.