Sweet William, a flower in the carnation family, thrives in alkaline soil. The 1- to 2-foot plants produce pink, red or white flowers that loosely resemble small carnations. Sweet Williams are biennials, plants that live for about two years.
Coral bell flowers and foliage show a wide range of colors. The bell-shaped flowers form on a long stock. Of the many varieties of coral bells, some tolerate a wide range of soil types. Many varieties grow best in a shady site.
The uniquely shaped and very hardy coneflowers grow up to 4 feet tall. The colorful blossoms range from orange, purple and white to pink. They thrive in most types of soil, including alkaline soil, and grow throughout the United States.
Small, star-shaped flowers are often abundant on phlox plants. Creeping phlox is a perennial ground cover, while garden phlox plants grow 2 to 3 feet tall. Phlox often grows successfully in alkaline soil.
Often the spiky flowers on salvia plants are a bright red color. But there are many varieties of salvia, and the flowers have a wide range of colors. The annual bedding flowers have a tolerance for alkaline soil.
The drought-resistant yarrow plants grow up to 3 feet tall. The blossoms are often white or yellow, and the foliage is fernlike and feathery. Yarrow flowers grow successfully in alkaline soil.
Despite the name, daylilies are not true lilies. The very hardy flowers grow in a wide range of soils and require little care. The blossom colors range from apricot and gold to pink and red.