Sherman Duffy was an avid gardener in Illinois who wrote garden articles during the early 1900's. He tried to reproduce in the hot Midwestern summer, the color combinations that worked so well under gentler English skies.
One trick he tried was to plant something white between various colors so that they didn't clash with each other. Another was to stick to only two or three colors in each bed. For example he tried blue, pink and pale yellow together. But he kept searching for a plan with a good color scheme that would continue to unfold month after month until frost.
He finally decided that the secret was overlapping and interlacing colonies of plants that bloomed at different seasons so that no space in the bed was ever vacant. He selected plants with a view towards harmony of growth and color across all seasons.
As some plants ebbed, others took over. One of his Illinois borders was dedicated to deep yellows, dark purples and bright reds. Hollyhocks and sunflowers in the back, then coreopis, gaillardia and Shasta daisies interwoven with hardy chrysanthemums, butterfly weed, red hot pokers, day lilies, rudbeckias, oriental poppies and fall blooming asters. In front he placed dianthus and annuals.
Duffy created this garden in 1910, but as a design template it is timeless.