Flowers With Impact

Blue to Purple

• For tall spikes of blue-purple flowers, plant delphinium (Dephinium spp.). These perennials grow up to 8 feet tall and produce blue, purple, violet and white flowers described as "spectacular" by the University of Nebraska Lincoln Extension. Delphiniums grow in sunny sites with rich, well-draining soil and are hardy in U.S. Department of Agriculture plant hardiness zones 3 to 7. When grown in groups, the grape hyacinth (Muscari armeniacum) blooms with purple spires that Fine Gardening describes as "particularly spectacular." Hardy in USDA zones 4 to 8, these perennial bulb flowers grow to 12 inches tall and grow well in moist, well-draining soil and full sun exposures.

Pink to Red

• For "striking" pink color, Cornell University recommends planting pinks or sea thrift (Armeria maritima). Hardy in USDA zones 4 to 8, these 12-inch-tall perennials brighten a border or rock garden with showy pink flowers atop dark green foliage. Pinks grow best in sunny, well-draining sites and bloom in late spring. Plant muhly grass (Muhlenbergia capillaris) in groups for an effect that's "spectacular," reports Fine Gardening. This perennial grass flowers in fall with airy, pink inflorescences atop fine, 6-foot-tall stems. Plant muhly grass in full sun to partial shade in USDA zones 6 to 10, where it tolerates poor soil.

Yellow to Orange

• The University of Nebraska Lincoln describes the crown imperial (Fritillaria imperialis) as unsual, striking and beautiful. This bulb grows to 3 feet tall and flowers in spring with orange and yellow flowers that hang from glossy bracts of green foliage. Crown imperials thrive in rich soil and full sun exposures and are hardy in USDA zones 5 to 9. For year-round color and texture, the Chinese hibisbus (Hibiscus rosa-sinensis) grows from 15 to 30 feet tall and blooms with yellow-orange single or double flowers. Hardy in USDA zones 9 to 11, this evergreen perennial puts on a showy floral display and thrives in full sun to partial shade and moist, acidic soil.

For Fragrance

• As its name suggests, "Clouds of Perfume" blue phlox (Phlox divaricata "Clouds of Perfume") fills the air with scent. Though it only grows to 12 inches tall, this perennial spreads to 2 feet wide, creating a semi-evergreen ground cover. Blue phlox blooms in spring with aromatic, blue flowers that attract pollinators. It grows in USDA zones 4 to 8 and prefers shady, moist sites. Other flowers with a striking fragrance include the hedgehog rose (Rosa "Blanc Double de Coubert"). This 6-foot-tall rose blooms from spring to autumn with aromatic white blossoms. It's hardy in USDA zones 3 to 9 and thrives in moist, rich sites in full sun to partial shade.