Despite its soft, sweet name and wedding-bouquet reputation, baby's breath (Gypsophila paniculata) has a dark double life as an invasive weed. The tiny white blossoms that fill out flower displays grow on perennial plants that grow to 3 feet tall and wide. Hardy in U.S. Department of Agriculture plant hardiness zones 4 through 9, baby's breath has escaped cultivation and naturalized across much of the northern United States and Canada. If you decide to grow baby's breath, consider the annual plant (Gypsophila muralis), which is not invasive.
Locate your baby's breath plant in full sun for fastest growth. The plant also grows in partial sun. Select an appropriate location the first time around, because baby's breath does not do well if transplanted.
Plant baby's breath in any well-drained soil that is alkaline, with a pH range from 7.0 to 7.5. In the wild, the plant grows well almost anywhere, on sandy, grassy or loamy soils in disturbed areas, beside roads, and even in ditches and cemeteries. As long as the soil drains well, your baby's breath should do well.
Space the plants a yard apart -- each should grow some 3 feet wide. If you plant in a windy area, stake the plants when they are young. As a baby's breath plant matures, it becomes stiffer, and staking without breaking becomes more difficult.
Water weekly after planting for the first few months. Irrigate infrequently if at all after the plant is established in your garden. Baby's breath prefers dry soils and tolerates drought.
Avoid fertilizer. Baby's breath grows vigorously on dry, infertile soil and generally does not suffer from pest attacks or disease.