Topsoil is necessary for plant growth but, on its own, is not the ideal environment for growing healthy plants. Fortifying topsoil with peat moss, which is decomposed plant matter, helps retain moisture and break up clay or sandy soil so plants can absorb nutrients and water. Peat moss is also an effective soil addition for container gardens.
Things You'll Need
Rototiller or rake
For container gardens, fill each container 65 percent full with topsoil, then finish with peat moss. Mix them with a small garden shovel or your hands.
Rake or rototill 1 inch of peat moss for every 4 inches of topsoil in your garden. The topsoil and peat moss mix should make up the top 6 to 12 inches of your soil.
Dig the holes required for your flowers or vegetables and begin planting, making sure to saturate the container or garden area thoroughly to help the plants take to their new peat moss and topsoil mix.