Baby’s breath plants have become somewhat of a cliché in floral arrangements, but you may fall in love with them all over again in the flower garden. The plants look dainty but hang tough in dry sandy soils and cold climates, and they are deer resistant to boot. Baby's breath plants belong to the Caryophyllaceae family, which includes other flower garden favorites like the perennial dianthus (Dianthus superbus, etc.), border carnation (for example, Dianthus caryophyllus 'Clarion'), and sweet William (Dianthus barbatus).