I place the pots on an old cookie sheet to catch any water spills. Therefore, I plant more vegetables than flowers. It helps cut back on my grocery expenses. Some plants are more costly to maintain than others. Many require lots of water, special fertilizer and costly pesticides.
Roses are a good example of a high maintenance plant.
Make sure that you know what your plants will require before deciding what to plant. Xeriscaping is worth looking into. It is the science of low maintenance landscaping. This does not mean that your yard will be filled with cactus and rocks. There are many vegetables, flowers and shrubs that do well in dry areas.