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.
licorive silver, excellent filler or accent plant, 8-16" sometimes taller.
Sedum, Annual, PW, Lemon Coral, these plants are amazing, fast growing, tough, trailing, not hardy in Vermont but they go even with snow on them. 3-6" tall, nice trailing/spreading variety
Vinca Minor, Illumination, zone 5 perennial, sun-shade, 3-6" tall, nice trailing/spreading variety
Vinca Major, Annual, PW, Wojo's Gem, sun-shade, 3-6" tall, nice trailing/spreading variety, not perennial in Vermont