Phlox Seeds

what we love about phlox seeds

Often mistaken for Phlox paniculata, Phlox drummondii (aka Drummond’s phlox or annual phlox) is an upright annual that is hardy in zones 3 through 9. Growing in showy clumps of dense dainty flowers, phlox blooms mid-summer through early fall and has a sweet scent that will attract butterflies, hummingbirds, and perhaps even some humans to your garden! Phlox make excellent cut flowers so don’t resist cutting a few stems when in peak bloom to add pinks, purples, and whites to your bouquets.

how to plant and grow phlox

Direct seeding of phlox seed is recommended. As soon as soil can be worked in the spring, sow phlox seed and cover with fine soil about 1/8 inch thick. Unlike many flower species, phlox requires darkness to germinate. Thin plants to eight to twelve inches when the first true leaves appear on new seedlings. Phlox dislikes their roots disturbed so take extra care when seeding them indoors and transplanting. Sow seedlings indoors in plug cells four to six weeks before the risk of frost has passed. Cover seeds with soil and keep out of light until 10 to 15% of seedlings have germinated. Harden off for seven days and transplant with care once true leave are established.

caring for your phlox seedlings

Phlox seedlings should be planted eight to twelve inches apart in full sun to partial shade. Plants especially appreciate afternoon shade during the heat of summer. They are susceptible to powdery mildew so providing space between plants is important to promote airflow and prevent disease. Avoid watering overhead for this reason as well. Phlox plants require regular watering to establish but are relatively drought-tolerant once they begin to grow. They tend to do poorly in extreme heat so use mulch to keep the root zone moist and cool during hot, dry summers. Phlox do not like to be overwatered and can struggle in heavy, water-logged soils. Fertilize with compost or a well-balanced fertilizer in early summer to encourage extended flowering. Deadhead as flowers die back to keep plants neat and clean and to promote new blooms.

For more information about planting, growing, and caring for phlox seeds, see the Phlox Seeds Planting Guide.