Companion Flowers for Sea Thrift

Perennials

• Perennials live for at least three years, but some survive for many more. Compatible choices for sea thrift include asters. These 1- to 4-foot-tall perennials bloom with blue, white and pink flowers from late summer through fall. They prefer full sun and well-drained soil and are hardy in USDA zones 5 to 8. The blue wild indigo (Baptisia australis) blooms with tall spikes of blue flowers in spring. It grows from 3 to 4 feet tall and prefers full sun and well-drained soil. This North American native is hardy in zones 3 to 9.

Annuals

• Annuals only live for one growing season, but they tend to bloom longer than perennials. Compatible species include ageraturm (Ageratum houstonianum), which flower through the summer with pink, white and blue blossoms. They grows from 6 to 24 inches tall and prefer full sun. Ageratum tolerate drought. Cosmos (Cosmos spp.) bloom from spring through fall in a variety of colors, including red, pink and white. These sun-loving annuals grow from 3 to 6 feet tall and prefer well-drained soil.

Ground Covers

• Ground covers fill in empty spots around your sea thrift and many bloom with attractive flowers. Rock soapwort (Saponaria ocymoides) produces tiny, pink flowers in spring and has dark, evergreen foliage. This fast-grower is hardy in USDA zones 2 to 7, prefers full sun and tolerates a range of soils. It grows from 4 to 8 inches tall but spreads to 3 feet wide. White stonecrop (Sedum album) grows well in full sun and well-drained soil. This evergreen grows from 3 to 6 inches tall and forms a dense mat of small leaves. It produces panicles of white flowers in summer and is hardy in zones 4 to 9.

Ornamental Grass

• Ornamental grass provides a low-maintenance alternative to tall shrubs that will allow sun and air circulation near your sea thrifts. Beard grass (Andropogon virginicus) is hardy in USDA zones 3 to 9 and grows to 4 feet tall. This upright grass grows in a clump of green foliage that turns dark-purple and orange in fall. It requires full sun and tolerates a range of soils, including sand. Big bluestem (Andropogon gerardii) also grows well in full sun and sandy soils. This upright to arching grass has green to blue-green foliage that turns orange and red in autumn. It grows from 4 to 7 feet tall and is hardy in zones 4 to 9.