1065 Phlox paniculataCommon Names: garden phlox, summer phlox Family: Acanthaceae (acanthus Family)
Garden phlox is an herbaceous perennial that returns consistently year after year from a thickened root stock. It gets as large as 4 ft (1.2 m) tall, with thin, finely toothed ovate or elliptic leaves 2-5 in (5-13 cm) long. The inflorescence is a large pyramidal cyme to 8 in (20 cm) across of salverform flowers, each about one inch (2.5 cm) across. (Cyme: a branched flower cluster; Salverform: a flower with a long tube that expands into flat petal-like lobes.) Phlox flowers have five lobes. The flowers are fragrant and their color varies from white to lavender in wild plants, with other colors available among the many named cultivars. Garden phlox has a long blooming period from early summer well into autumn.
The wild form of Phlox paniculata grows naturally in the eastern U.S. from Wisconsin and Ontario, west to Missouri and Arkansas and thence south to eastern Texas and central Georgia. This pretty native occurs sporadically on rich, moist soils along stream banks and in open woods. There are hundreds of cultivars hybridized and selected for flower color, size and fragrance.
CultureTaller cultivars may have to be staked. Good ventilation helps prevent foliage diseases. Light: Grow in full sun to partial shade. Moisture: Garden phlox does best in fertile, moist but not soggy, soil. Garden phlox is susceptible to powdery mildew, so water in the morning so the foliage can dry out quickly, or better yet, just water the ground around the plant, and not the leaves. Hardiness: USDA Zones 4 - 8. Propagation: Garden phlox may be propagated by root cuttings or dividing the offshoots. Softwood stem cuttings (before flower buds form in spring) are easy to root.
Garden phlox is a very popular perennial for borders and beds. Its robust, upright habit, long blooming period, and colorful flowers ensure that it never goes unnoticed. Deadhead to encourage constant flowering. The wild species, Phlox paniculata, is seldom found in cultivation. However there are hundreds of cultivars to choose from, including those with white, pink, salmon, scarlet, purple and lavender flowers, and some with variegated foliage. Some get up to 4 ft (1.2 m) tall, and others stay under 2 ft (60 cm). 'David' is a white flowered form that is especially resistant to powdery mildew.
So many of our horticultural garden flowers are originally from the Old World, that it is nice to have the phloxes: true North American natives. Among the more than 70 species in the genus, at least 16 have been brought under cultivation. The group includes mat and cushion forming creepers suitable for rock gardens; delicate woodland herbs for shady naturalistic settings; dainty annuals for bedding; and robust perennials for borders and the cutting garden. Phlox drummondii is a colorful annual that is often planted (and grows there by itself!) along highways.
Steve Christman 10/29/07; updated 10/12/08, 8/9/12