Use an odd number of plants when planting annuals, perennials, trees, and shrubs.
Use a thriller, filler, and a spiller in your container garden. Choose a tall focal plant for the center (thriller), medium-height plants around the focal plant (filler), and trailing plants around the edge (spiller). Feel free to mix annuals and perennials.
Plan for a succession of color throughout the season. Check the bloom times on perennials and be sure to include a mix of spring, summer, and fall bloomers. Add annuals for ongoing color. Tuck containers into your garden bed or border for an extra pop of color in the garden.