You can also get a complete soil chemistry profile from your County Cooperative Extension office for a small fee. If you plan on growing your shade garden below deciduous trees, do not allow your plants to become suffocated by an overabundance of leaves in the fall. While a leaf mulch is beneficial through the winter, a too heavy covering of leaves may crush and kill your plants, or possibly lead to disease. You should also be aware that water dripping from overhead branches can cause damage and erosion to the soil as well as your plants. Spring is a great time to plant your shade garden because temperatures are cool and rainfall is abundant.
Roots have a chance to become established before it gets hot and dry.
Different plants require different degrees of shade ranging from dense shade to dappled or partial shade. You need to study and understand what kind of light you have to achieve the optimum conditions for what you want to grow. You need to also consider that a plant which needs full, dense shade to survive the summer in a hot southern state will do just fine in partial shade in a cooler northern location. Instead of trying to change existing conditions, match your plants to the site. It's not only easier on the environment but also a lot less work for you.