Though flowers are the star of the summer show, the use of foliage plants in your window boxes, planters and baskets can really set the floral stage, and even add a bit of magic.
One plant which I have come to see as indespensible for bedding and large container use is: Perilla. Perilla looks and grows just like coleus, but it loves the heat and sun. Once established it thrives on little water which is great for those sunny containers.
English Ivy, Gold Child. Zone 5 perennial. Vigorous, easy to grow, can tolerate full sun to full shade, medium-sized, variegated leaves with a lobed, ivy shape and heart-shaped base. leaf color is gray-green with irregular, wide, gold-green margins. Excellent as a living ground cover. 2008 Ivy of the year
Vinca Minor, Illumination, zone 5 perennial, sun-shade, 3-6" tall, nice trailing/spreading variety, makes a nice, brightly colored ground cover in sun or shade.