2. Using gravel in the bottom is terrible for drainage; either fill with good, pre-moistened, sterile potting mix completely, or to reduce weight for enormous containers, use a upturned plastic nursery pot or a sealed bag of packing peanuts in the bottom third.
3. Cover the drainage holes with a coffee filter or used dryer softener sheet before filling to within 3 to 5 inches of rim. [Only use pots with no drainage for water gardens or pots on covered porches.]
4. Arrange the plants in the pot before adding the final potting soil, repositioning until satisfied with the arrangement.
5. Add a slow release plant food, such as Osmocote, to the remaining soil. Firmly fill around the plants, avoiding air pockets. The soil level should be at least 1 inch from the rim, to allow watering without runoff. [Add Osmocote again in 3 months.]
6. Let the pot material and its color determine the mood of the entire display, also keeping in mind the background of the nearby buildings or landscape.
7. Choose plant material with various textures and flower or leaf size. Don't overlook perennials, grasses, shrubs or tropical houseplants as elements - many of which can overwinter in the ground or indoors. Foliage can make as big an impact as flowers and don't need deadheading, as flowers will require.
8. Use no more than 3 colors per pot, including any leaf variegation, which repeat parts of each other, the leaf, petals or center.
9. Hot tropical colors are best seen and appreciated from a distance, while cool pastels belong where the viewing is intimate or close to windows and doorways.
10. Chartreuse and dark purple toned foliage blend with everything. Vibrant or pale colors displayed against those in the same tonal range won't overpower each other. White variegated foliage is best with pastels, while yellow splashed leaves compliment warm shades. Be sure not to mix the two.