Description of annual phlox: Annual phloxes grow from 6 inches to 11/2 feet tall. The flowers are in large clusters of many colors and many shapes. Colors include pink, red, rose, white, lavender, scarlet, crimson, and yellow.
Growing annual phlox: Annual phloxes grow best in well-drained, sandy soil, high in organic matter. They require full sun and must receive continuous moisture during the growing season. Good air movement around the plants will prevent mildew. Plant in the garden as soon as the danger of frost has passed. Space 6 inches apart. Pinch the tips to encourage branching. At midsummer, shear the plants back halfway to reinvigorate flowering.
Propagating annual phlox: By seed. Sow plants outdoors where they are to grow after the last frost is due. Thin to the desired spacing. For earlier bloom, start plants indoors 4 to 6 weeks before setting out. Seeds germinate in 15 to 20 days at 55 to 65 degrees Fahrenheit. Transplant in clumps of several plants to get a full color range.
Uses for annual phlox: Grow phlox in beds or at the front of borders. Use them as edgings. Intermix them with other flowers in informal plantings and cottage gardens. Phlox are good container plants and hold well in water when cut.
Annual phlox related varieties: Petticoat Mix is very dwarf with a mix of all colors. Cecily is a mixture with a high number of bicolors with contrasting eyes. It is also a dwarf variety. Tall Finest Mixed has large flower heads on plants up to 20 inches tall. Twinkle, an award winner, is a mix of ringed, pointed, starlike flowers. The 21st Century hybrids are bicolors with darker eyes that are very heat tolerant.
Scientific name of annual phlox: Phlox drummondii