This boulevard site uses the tall stems of yellow Greyheaded Coneflower and mid-height Purple Coneflower to create dynamic movement in a slight breeze. Long flower stems are see-through and do not block site lines. These midsummer blooms have complementary colours: yellows and purples, while their similar shapes create unity.
Purple Gayfeather spikes provide an interesting contrast.
An upright grass species occupies the area near the trees. It is too tall for the boulevard.
A low border would benefit this garden by keeping edges neat and restricting the leafy overhang which could pose a hazard.