Making Soil-based Potting Media

The following is a basic recipe for soil-based potting media. In this recipe, garden loam soil, coarse construction sand, and sphagnum peat moss are combined together in equal parts by volume:

1. Start with one gallon of sterilized loam soil, commonly called garden soil and sold at garden centers, and pour it into a clean, empty bushel basket. Sterilized loam soil is worth the cost to avoid disease, insect, and weed problems that may exist in unsterilized soil. Soil taken directly from the garden may be contaminated with these pests, causing possible future problems such as dead, deformed, or stunted seedlings. Weeds in garden soil generally grow vigorously and crowd out desired seedlings by competing for nutrients, water, air, and light.
2. Add one gallon of moist, coarse sphagnum peat moss, followed by one gallon of coarse sand, perlite, or vermiculite.
3. Adjust the texture of the medium to create a loose, well-drained mixture. Sand feels gritty and clay feels sticky. If the potting soil feels too sandy, more peat moss should be added. If the potting soil feels too sticky, extra sand and peat moss should be added. Adjust the texture by adding small portions of sand and/or peat moss until you are satisfied with the texture.