• While many butterfly-attracting plants have brilliantly colored blooms, tall, white-flowering perennials bring a refreshing, crisp touch to butterfly gardens. Placed for architectural interest at the back of a butterfly garden, their foliage and blooms provide counterpoints for lower plants. Choosing these plants according to their blooming seasons will bring a spring-to-fall stream of brightly hued butterflies to your landscape.
  
  

Mississippi Penstemon

• Standing up to 5 feet high and semi-evergreen where winters are mild, Mississippi penstemon (Penstemon digitalis) is an April to July bloomer, depending on location. Common in prairies and fields from Maine south to Mississippi and west to Texas, it brightens gardens with showy, stem-topping clusters of white, tubular flowers. The blooms appear even brighter against the plants' narrow, elliptical deep green leaves. Purple stripes lining the flowers' throats guide bees to the plants; hummingbirds as well as butterflies are other regular visitors. Mississippi penstemon tolerates dry, shady spots. It performs best, however, in sunny spots with averagely moist, well-drained soil. Massed plantings make the most impressive display, advises the Missouri Botanical Garden.
  
  

Common Boneset

• An aster family perennial, common boneset (Eupatorium perfolatium grows from 4 to 6 feet high. Between June and October, butterflies swarm to prairies and bogs from the Atlantic and Gulf coasts to Oklahoma when common boneset blooms. Its tiny, fuzzy flowers appear in flat, dense clusters atop stems of large, lancelike deep green leaves. Birds also visit the plant to feed on its seeds, reports the Lady Bird Johnson Wildflower Center. This perennial is attractive as a marginal water garden plant as well as in butterfly gardens. Tolerating sun or partial shade, it likes consistently moist, sandy or clay soil. Plants in dry locations are vulnerable to leaf scorch.
  
  

False Aster

• Another perennial common in sandy or gravelly soils across eastern United States, wild false aster (Boltonia asteroides) grows 5 to 6 feet high. Flowering form late summer to fall, the 'Snowbank' false aster cultivar stands up to 4 feet high with yellow-eyed, white, daisylike blooms. The tiny flowers, occurring in loose clusters on branching stems, can obscure the butterfly-attracting plant's lance-like grayish-green foliage.They make excellent cut flowers, advises the Missouri Botanical Garden. Like all boltonias, Snowbank likes full sun and averagely moist well-drained, soil. It isn't fussy abut soil type.
  
  

Goat's Beard

• A larval host for the dusky azure butterfly, goat's beard (Aruncus dioicus) is a shrubby perennial standing from 4 to 6 feet feet tall and up to 4 feet wide. Between spring and early summer, its erect stems rise above clumps of deep green, compound leaves. Each stem has plumes of tiny, creamy white astilbelike flowers, according to the Lady Bird Johnson Wildflower Center. The densely stamened blooms on male plants are showier than those of females. Native to the woodlands of the eastern and Pacific Northwest states, goat's beard likes partial shade and well-drained, moist or wet acidic (pH below 6.8) soil.