The key to a dramatic container garden display is to choose several containers with a similar style, or color or made from the same material, such as terracotta, stone or wood, but in varying sizes. While tall planters add height and interest to the arrangement of containers, you may shy away from large containers due to the expense of filling them with quality potting mix. Fortunately, there is a trick to filling tall planters that reduces the reduces the cost of soil and makes them lighter, too.
Fill the bottom one-fourth to one-third of your tall container with filler material, such as packing peanuts, 2-liter soda bottles or aluminum cans. The filler material takes up room while lightening the weight of the finished container. What you use for filler material doesn't matter as long as it is lightweight, nontoxic and will not break down or deteriorate during the season.
Place a piece of landscape fabric, cut to the size of the interior of your planter, over the layer of filler material. The landscape fabric prevents the soil from falling into the cracks in the filler material, while allowing water to drain through.
Fill the rest of the planter with commercial potting mix or your own mix. Mixing 1 part peat moss, 1 part all-purpose potting soil, or garden soil, and 1 part perlite makes a lightweight potting mix suitable for containers.