Blue phlox Phlox divaricata 'Blue Moon' Photo/Illustration: William Cullina 1 2 3 4 5 6 7 8 9 10 11 Blue phlox (Phlox divaricata 'Blue Moon') floks div-air-ih-KAY-tah Genus: Phlox This cultivar of the popular blue phlox has round, full flowers with overlapping petals. It is noteworthy for its particularly rich blue-violet color. Use it in rock gardens or alpine houses, in a dry wall, or as edging. Noteworthy Characteristics: Spreads by roots, creating a semi-evergreen groundcover. Care: Grow in humus-rich, fertile, moist but well-drained soil in part shade. Propagation: Insert basal cuttings in spring, or take root cuttings in early autumn or winter. Problems: Powdery mildew, stem canker, rust, Southern blight, stem nematodes, Cercospora and Septoria leaf spots, leaf miners, and caterpillars. Overview Height 1 ft. to 3 ft. Spread 1 ft. to 3 ft. Growth Habit Spreads Light Part Shade Only Moisture Medium Moisture Maintenance Low Characteristics Fragrant Flowers, Self Seeds, Showy Flowers Bloom Time Early Spring, Spring Flower Color Blue, Purple Uses Beds and Borders, Cut Flower Style Rock Garden, Woodland Garden Seasonal Interest Spring Interest Type Perennials Phlox divaricata 'Blue Moon'View the discussion thread.