Gardeners frequently add color and ornamental interest to summer landscapes by planting flowers that bloom in August. If you would like August-blooming flowers, select plants according to bloom time, flower color, intended use, general cultural requirements and your United States Department of Agriculture (USDA) hardiness zone. Various flowering plants bloom during the month of August.
Snapdragons (Antirrhinum majus), herbaceous perennials in the Scrophulariaceae plant family, typically perform well in USDA zones 7 to 10. Mature snapdragons range from 12 to 36 inches in height with spreads reaching up to 12 inches. Dragon-shaped flowers appear from mid-spring through the first frost. The vibrant blossoms come in many colors, including purple, pink, red, yellow and bicolored. The shiny, deep green leaves sometimes suffer from fungal leaf spots and downy mildew. This flowering plant likes rich, moist soils in fully sunny locations. Gardeners often use snapdragons in borders, flowerbeds, containers and cutting gardens.
Ox-eye daisies (Telekia speciosa) belong to the aster plant family (Asteraceae) and prefer well-drained, moist soils in partially shady to fully sunny positions. Native to European mountainous regions, this perennial performs well in USDA Zones 3 to 7. Ox-eye daisies range from 4 to 6 feet in height and 2 to 3 feet in width. The flowers bloom in August and September, featuring yellow, rayed petals surrounding flat, orangish-yellow central disks. The hairy green leaves release an aroma when bruised or crushed. Slugs and snails sometimes feed on the foliage. The ox-eye daisy works well in woodland gardens, stream margins and border rears.
Mature button flowers (Gomphrena haageana) range from 24 to 30 inches in height and 12 to 18 inches in width. This perennial performs well in USDA zones 9 to 11, thriving in well-drained soils that receive plenty of sunlight. This globe amaranth family member (Amaranthaceae) produces flowerheads consisting of small, trumpet-shaped, yellow flowers with colorful, orange flower bracts. These flowers bloom from early summer through the first frost. Gardeners often plant button flowers in rock gardens, borders, containers and cutting gardens.
English lavender (Lavandula angustifolia) typically grows well in well-drained, alkaline soils that receive full sun. Winter hardy in USDA zones 5 to 8, English lavender plants range from 2 to 3 feet in height and 2 to 4 feet in width. This mint family member (Lamiaceae) bears aromatic, grayish-green foliage often used in potpourris, perfumes and sachets. The purple flower spikes bloom from June through August. Root rot and leaf spot sometimes occur in poor-draining soils. English lavender typically performs well in scented gardens, herb gardens, borders and rock gardens.
Betony (Stachys maxima), a Lamiaceae plant family member, performs well in USDA zones 4 to 8. Betony plants range from 9 to 18 inches in height with similar spreads. This perennial grows well in moist, well-drained soils in partial to full sun. Betonies planted in shady areas often suffer from powdery mildew and leaf spots. The tube-shaped, rose to purple flowers bloom in showy spikes from midsummer through early autumn. Gardeners often mass plant betony as groundcovers, borders and edging plants.