1. Use a big container; the bigger the better.
2. Use good potting soil, not garden soil.
3. If planting with flowers from hanging baskets, take them out of the pot, loosen the roots and repot in a slightly larger pot with more soil.
4. Did I mention using a bigger pot?
5. Add an organic fertilizer every 2 weeks during the growing season.
6. Read this article on some new and exciting varieties of plants to try in your containers!