Plant pots are available in an array of sizes from only 3 or 4 inches in diameter to as large as 4 feet, for planting small trees. Choose a pot that will support the total mass of the mature root system of the plant you will grow in the pot. The container should include drainage holes to prevent water damage to the plant's roots.
A potting mix made from compost, peat, manure and other rich, organic materials provides the best growing medium for starting potted plants, because the medium provides rapid water drainage. A soil-free growing medium also protects potted plants from weed seeds found in soil and many plant diseases that start in the soil.
Fill the plant pot with growing medium, leaving at least 1 inch of space at the top of the pot to prevent water from spilling over the sides. Plant seeds or bulbs according to package directions, adding extra seeds and bulbs to increase your chances of successful germination. Thin extra growth later, as necessary.