Here is a collection of plant ideas, the descriptions and tips on how to grow them in flower gardens with damp summer heat. Some plants have cultivars that were developed able to tolerate hot humid growing conditions.
There are many types of yarrow. However, the fern leaf yarrow, Achillea filipendulina ‘Coronation Gold’ is the best yarrow at tolerating hot and humid weather. It grows in full sun, is hardy in zones 3 – 8 and shorter than the species, growing only 2’ – 3’ tall. It is the long narrow gray-green leaves with serrated margins that give the plant a fern-like appearance.
Achillea ‘Coronation Gold’ attracts butterflies and is drought tolerant, making it appropriate for a sustainable garden. The flowers bloom June through August and are excellent for dried flower arrangements.
Ajuga is a perennial plant with evergreen leaves that forms a dense groundcover. It fills in empty garden spaces by spreading so planting near grassy lawns should be avoided.
Although the plant tolerates poor soil, it grows healthiest with good drainage and air circulation in full sun to part shade. The flowers begin blooming in late spring continuing through early summer. This perennial plant attracts bees to a garden.
Ajuga temorii ‘Dixie Chip’ and ‘Mint Chip’ tolerates hot and humid growing conditions. Each cultivar is hardy in zones 5 – 7, grows 3” tall and has deep blue flower spikes. However, each plant has differing leaf structures including:
Dianthus gratianopolitanus ‘Bath’s Pink’ is hardy in zones 3 – 9, grows well in full sun and well-draining soil. The plant gets 12” – 15” tall and forms a dense mat of foliage. The pink flower petals are fringed on the edges and bloom June through July. The leaves are bluish green.
Dianthus ‘Bath’s Pink’ is a low maintenance plant because it requires infrequent dividing. The plant is easy to grow, attracts bees and would be appropriate for a fragrant garden.
This plant is commonly referred to as cheddar pinks which are native to southern England. Cheddar pinks are characterized as having bluish green linear foliage and fragrant flowers. Another example is Dianthus ‘Tiny Rubies’ that has double pink flowers, grows 5” tall and often used in rock gardens.
Rudbeckia hirta is a short-lived perennial primarily grown as an annual and usually susceptible to powdery mildew. Rudbeckia hirta ‘Tiger Eye™ Gold’ is a plant that tolerates damp summer heat, grows best in full sun but will tolerate light shade.
There are many types of Rudbeckia hira for annual plant gardens. Besides attracting pollinators, these plants are suitable for including in a sustainable garden.
Scaevola aemula ‘New Wonder’ is a weeping annual, commonly called fan flower. It is a tough, salt and drought tolerant plant that attracts butterflies and hummingbirds. This self-cleaning annual plant is easy to grow and appropriate for hanging baskets. Scaevola prefers full to part sun and planted in well-draining soil. It flowers early summer to the first frost.
Hot humid weather occurs during summer in locations as diverse as southern states like Florida or northern regions such as eastern Wisconsin. Many gardeners search for flowering plants that will thrive during hot humid summers.
Stokesia laevis ‘Purple Pixie’ is another perennial that is good for container plantings in hot humid weather.