When creating a butterfly garden, you need plants of varying heights, with tall plants 3 feet tall or taller useful for the back of the garden, for borders and for defining boundaries. You also need a place for the eye to rest amid the dazzling array of flower colors displayed to attract your winged visitors. White-flowered plants interspersed between brighter flower colors can lend unity to your garden and allow stronger colors to stand out well in contrast.
Prolific-flowering "Becky" shasta daisy (Leucanthemum x superbum "Becky") has sturdy stems that reach 40 inches tall and make 3-foot-wide clumps of yellow-centered, 3-inch-wide white flowers. Chosen by the Perennial Plant Association as the 2003 Perennial Plant of the Year, "Becky" blooms from June into September. Plants are hardy in U.S. Department of Agriculture plant hardiness zones 4 through 9. "Chocolate" white snakeroot (Eupatorium rugosum "Chocolate") has bronzy, lance-shaped leaves and purple stems. Broccoli-sized clusters of fuzzy white flowers form a mounded display atop the 3- to 4-foot-tall stems in summer and fall and attract many kinds of butterflies. Hardy in USDA zones 4 through 8, all parts of the plant are poisonous if eaten.
Plants Over 6 Feet Tall
For a background planting that highlights shorter foreground plants, consider a mass planting of delphinium varieties that reach 6 feet tall when they bloom. "Jill Curley" (Delphinium elatum "Jill Curley") rises over 7 feet tall, and "Elisabeth Sahin" reaches over 6 feet in height. Hardy in USDA zones 3 through 7, taller delphinium flower stalks may need staking. Robust plants of tall meadow rue (Thalictrum pubescens) can reach 6 to 10 feet tall, with fine, cloud-like, creamy white blossoms on stiff stems in late June to early August. Preferring moist conditions and sun to light shade, tall meadow rue grows in USDA zones 3 through 9.
Upright growth and tall flower columns lead the eye upward and make conspicuous targets for butterflies. "Wedding Candles" mullein (Verbascum chaixii "Wedding Candles") has open, closely-packed, white flowers centered with purple stamens above a rosette of crinkly green leaves. Plants grow to 40 inches tall in USDA zones 4 through 8. Resembling a living candelabrum, Culver's root (Veronicastrum virginicum) tall, branched flower stalks with soft white spires of flowers grows from 3 to 6 feet tall. Flowers can also be pink or tinged with blue, so choose plants when in flower to get white ones. Growing in USDA zones 3 through 8, Culver's root prefers moist soil.
"Alba" lavender hybrid (Lavandula x intermedia "Alba") reaches 48 to 52 inches tall with fragrant, creamy white spring flowers. Use flowers for fresh or dried floral arrangements. Plants are hardy in USDA zones 5 through 9. Tall garden phlox "David" (Phlox paniculata "David") has fragrant, pure white flowers in the summer and grows to 4 feet tall in USDA zones 4 through 8. This disease-resistant cultivar is good for cut flowers and grows rapidly. Remove old leaves in late winter before the new growth emerges.