Red is a vibrant color that is not only patriotic, but also a favorite of hummingbirds and butterflies. Bee balm, hollyhock, daylilies, perennial salvia, roses, columbine, veronica, asters, clematis and astilbe are all excellent choices for red flowers that bloom over an extended period. Red is a color that stands out in the garden and draws the eye to it. Think about using red flowers as the centerpiece of the garden. In a container, this group of plants would be known as a thriller.
White looks good by day and even better at night as the moonlight reflects off the flowers' petals. Popular perennial white flowers include salvia, roses, peonies, phlox, astilbe, daylilies, hollyhock, clematis, lilies and yarrow. White flowers will tie the patriotic garden together. In a container arrangement, these types of plants are known as filler. They are the plants that fill in any empty areas so the soil is not easily visible and are also responsible for creating the "full" look that most container arrangements have.
Blue flowers are a bit harder to find, but not impossible. Blue flowers are more of a lavender or purple than a true blue, although there are exceptions. Some good choices for blue perennial flowers are monkshood, salvia, clematis, columbine, Russian sage and dianthus. When choosing blue flowers for a patriotic garden, it is best to select them from a local nursery so you can see them in bloom to make sure they are the right shade. Think of blue flowers as the spillers of a container arrangement. In a container, these plants would spill over the edge. In a garden, use these plants to fill out the edges of the arrangement.
Now that you have a basic understanding of how most container gardens are created and where the various plants would go, use this information to create a patriotic container garden or a spectacular in-ground flower bed. For example, try combining a red clematis, with a white phlox and a blue salvia. This would be ideal for a midsummer full sun garden and depending on the plant varieties you chose, might even be in full bloom for the 4th of July. When choosing plants from a nursery, remember that most of them are forced to bloom earlier than normal, so find out what their normal bloom time is before planting them to avoid disappointment the following year.