With its airy form and hundreds of tiny flowers in white or pink, baby's breath (Gyposophila paniculata) provides your garden border with an interesting contrast to larger flowers and dense shrubs. It grows about 3 feet tall and wide in the standard size and about 1 to 1 1/2 feet tall in dwarf varieties. Baby's breath is also excellent for cut flowers and for dried flower arrangements. Baby's breath grows best in U.S. Department of Agriculture plant hardiness zones 3 through 9. It can also be invasive in some parts of the country.