Whether you are planting an entire container garden or only have one or two ornamental flowers you need to pot up, preparing your pots for planting gives the plants their healthiest start on life. Proper preparation also makes regular plant maintenance simpler, since prepared pots are more able to provide the basics of moisture and soil nutrition. Preparation is the same whether you are using a brand new potting container or one that has housed a plant before.
Choose the container to match the plant. Shallow rooted plants are fine in wide, shallow pots while those with long roots require deep pots. Choose clay or wood pots for plants that require slightly drier soil conditions and plastic pots suffice for most plants.
Wash the container in water containing one part bleach to 10 parts water, then rinse thoroughly. Air dry to ensure any remaining bleach evaporates.
Make additional drainage holes if necessary. Drill two to four ¼ inch holes in the side of the bottom of the pot if no drainage holes are present. Set the pot on top of wood blocks or rocks in the drip tray to aid drainage if holes are on the bottom of the pot. Use bricks for large pots.
Place a piece of wire mesh or a broken clay shard over each drainage hole so the soil doesn't run out of the pot when you water. Use a fine mesh such as window screening.
Fill the container to within 2 inches of the rim with a purchased potting mix. Soil-less mixes have better drainage and don't compact over time. Make your own mixture by combining one part sterilized compost, one part vermiculite and one part peat moss.
Mix in a slow release balanced fertilizer with the soil for each pot. Fertilize most potted plants every four weeks with a balanced liquid fertilizer thereafter.