Gardening in colder regions, such as USDA hardiness zone 4, makes it a little difficult to plant a variety of types of flowers. Zone 4 states like Minnesota, Alaska, and other northern regions with cold climates, require frost-tolerant plants with hardy root structures.
Trumpet honeysuckle is ordinarily an evergreen vine, but in colder regions like zone 4, it is a deciduous plant. It produces trumpet-like, fragrant blossoms that range in color from orange to red. Trumpet honeysuckle prefers acidic, well drained soil, and is a beautiful climbing flower for zone 4 yards and gardens. Being a deciduous plant, the trumpet honeysuckle will lose its deep green foliage in the fall, but the perennial plant blooms back to life in the spring and throughout summer months in colder regions.
Chamomile is an evergreen ground cover that produces several small blooms that fade from yellow to white. The flowers blossom in the spring and summer seasons in hardiness zone 4. The foliage is delicate and lacy in appearance and feathery to the touch, making it a plush and attractive ground cover if planted near pathways and garden ponds or fountains.
Ordinarily found potted in homes, the Persian violet makes a wonderful addition to any summer garden in the zone 4 regions. It's a bushy plant that produces several small blossoms that bloom in various shades of blue and purple, though on rare occasions the Persian violet will produce white flowers. Plant Persian violet against garden border plants in mid-spring for healthy and attractive flowers all summer.