• Hyacinths grow in zone 5.hyacinth image by Vita Vanaga from Fotolia.com
  
  The United States Department of Agriculture's hardiness zone 5 encompasses the northern portions of both the East and West coasts, and a swatch of the central states. This region experiences maximum winter lows of 20 below Fahrenheit. Finding perennial flowers and shrubs that withstand the cold is not difficult. Gardeners will find a wide range of spring and summer-blooming plants that can overwinter in zone 5, suitable for small garden beds, large garden plots and borders.
  
  

Hyacinth

• The common hyacinth (Hyacinthus orientalis) is a perennial propagated via bulb. This plant has white, pink or purple flowers that emit a strong, sweet fragrance. Hyacinth is one of the first flowers to come up in spring. Flower stalks grow up to 12 inches in height. Hardy as far north as zone 3, this perennial performs well in zone 5. The low-growing flowers work well in garden beds and along borders.
  
  

Rhododendron

• The rhododendron family (Rhododendron spp.) has over 3000 cultivars in the United States alone, notes Floridata. Many of these perennial shrubs perform well in zone 5, but exact cold tolerance varies plant by plant. Rhododendron bear pink, white, orange or red trumpet-shaped flowers, and have glossy dark green leaves. They range in size from 8 inches to 20 feet.
  
  

Oakleaf Hydrangea

• Native to the United States, the Oakleaf hydrangea (Hydrangea quercifolia) bears double or single white blossoms. This type of hydrangea is hardy to zone 5. In the fall months, the leaves change color. In the summer, this hydrangea flowers. This plant averages 6 to 10 feet in height and can spread equally wide, if not wider. Floridata notes that the "Snow Queen" cultivar is definitely hardy through all of zone 5, while other cultivars may not perform as well.
  
  

Purple Coneflower

• Purple coneflower or echinacea (Echinacea purpurea) is a summer-blooming perennial that resembles a daisy. This plant has been used medicinally by the Native Americans. Purple coneflower works well in cut and dried flower arrangements, and as part of a native wildflower garden. Hardy to zone 3, it grows throughout zone 5. The plant forms large clumps up to 3 feet wide; individual blooms reach 3 feet in height.