Show your true colors. A red, white and blue flower bed is a great way to combine your love of flowers with your love of country.
This garden is all about color. Petunia, impatiens, lobelia, verbena, pansies and bachelor's buttons can be found in all three colors. Red and white flowers present no problem. There are few "true blue" flowering plants, but there are some options. Keep in mind that in many cases the "blue" is actually light blue or purple and not true navy blue as in the flag.
Other choices that work in combination are:
Red - salvia, geranium, verbena, poppies, zinnia, begonias, mums, snapdragons and celosia.
White - geranium, alyssum, shasta daisy, salvia, mums snapdragons, verbena and zinnias.
Blue - ageratum, blue bells, lobelia, verbena and salvia.
A larger scale project could use hydrangea and lilac. These shrubs also offer shades of the desired colors.
To ensure corresponding bloom times and consistent size, the best bet would be to use the same family of plants if possible. Some choices, such as snapdragons (available in red and white), may grow tall enough to hide a smaller blue-blossoming choice.
Remember that annuals are more compact than perennials and make a better-looking "flag." Annuals also provide more color when planted in full sun. We would also recommend bedding plants instead of planting seed. Bedding plants have an established root system to get your project off to a good start, plus you get to enjoy it immediately.
Whichever plants you choose, deadhead the spent blossoms for continuous color and a neat appearance.