Creeping Phlox Not In Bloom . If you are growing lavender.plant your phlox & dianthus near the lavender. So assuming that it gets several hours or more of. Shop 2.96Quart Creeping Phlox (L6559) at from www.lowes.com Creeping phlox will mostly bloom vigorously for 3 to 4 weeks around middle spring till late spring. It’s indigenous to rocky and sandy areas, ledges, clearings, and slopes from michigan and new. If you are growing lavender.plant your phlox & dianthus near the lavender.