The most important thing in a garden is the quality of the soil. Nutrient composition and its ability to drain water determines whether a ground is suitable for the plants you wish to grow. Soil amendments such as wood chips, vermiculite, sand and peat moss add their qualities to soil. Peat moss is used in soils that require extra nutrients, aeration and have a hard time holding water. The decaying organic material in peat moss adds nitrogen and other nutrients to the soil.
Test the soil of your garden using a home pH test or by sending soil samples to a local university extension. A pH test is available at many gardening centers. Peat moss will add to the acidity of the soil, so highly acidic soil should not have peat moss added.
Determine the amount of peat your soil requires to balance the acidity of the soil and to add moisture retention. This will depend on your soil composition and what you wish to plant.
Mix one part peat moss into two parts soil. Test the soil as you add the peat moss by squeezing it. Soil should form into a ball when squeezed, but break apart easily when probed with the hand.
Add the peat moss to the top of the gardening area at till it into the soil using a rototiller.