Buy a large planting container and you will undoubtedly be faced with filling it with bags and bags of potting soil. This method of filling pots is unnecessarily costly and wasteful. One option is to use a cheaper potting soil for the bottom half and a better quality soil for the top. Some manufacturers have even addressed this need, selling inserts and other materials to take up space. A cheaper option is to use items you already have on hand.
Place the pot in the location where you plan to place it permanently. Large pots, especially once filled with soil, are heavy and difficult to move.
Fill the bottom 1/4 to 1/3 of the pot with a filler. Use lightweight materials such as small pieces of Styrofoam, packing peanuts, crushed aluminum cans or empty plastic bottles. Don't use a bio-degradable material, as it will degrade over the season.
Cut a piece of landscape fabric large enough to cover the filler material. Place the layer of landscape fabric over the filler material so the soil is unable to work its way between the spaces of the filler.
Pour potting soil on top of the landscape fabric.