Plant 'Blue Paradise' in full sun and in fertile, moist soil, where it will grow to 40 inches and produce elegant panicles of flowers from July to August. Dutch landscape designer Piet Oudolf produced this mildew-resistant perennial that bears a spicy vanilla clove fragrance. The flowers open a deep blue with white eyes and take on purplish shades during the heat of the afternoon, then regain their original indigo coloring in the evening. They attract butterflies and hummingbirds.

The paniculata species of phlox is the most magnificent, and there is a huge selection to choose from.