Planting in a large container can be very useful for making stunning raised or container gardens, but filling very large containers with potting soil can become very expensive. Many container plants do not have extensive root systems and can fare very well with less soil than many large containers allow for. Using a false bottom, either purchased specifically for your pot or making one yourself, can help save on the amount of soil that is used and help make a large container lighter and easier to move.
Place the container into a tray that is at least a couple of inches larger than the potting container. This will help to catch any excess fluid on watering days.
Set your large container in the place where you are going to keep it. These containers get very heavy and it is possible that you won't be able to move it after it is filled if you use heavy materials or if the container is very large.
Place a bucket, plastic bowl or other large, sturdy container upside down inside the planter. Be sure, when deciding what to use, that it will allow several inches of soil to be placed on top of it. Using a shallow bucket or bowl works best because this will leave enough room to plant above it.
Fill in any large gaps around the edges of the bowl or bucket with any non-soluble materials such a styrofoam packing peanuts, crushed aluminum cans, rocks or broken block pieces.
Lay a sheet of landscaping material over these pieces and flatten out as well as possible. The landscaping material will hold in the soil but still allow water and air to pass through.
Fill the remainder of the planting container with your desired potting mix and plant.