Overview
Phlox speciosa is a clump forming, matforming herbaceous perennial in the genus Phlox, part of the Polemoniaceae family, with deciduous, evergreen foliage. Phlox speciosa grows best in full sun, and tolerates most soils and any pH. Its UK hardiness is rated H7. Suggested uses include cottage and informal garden, low maintenance, banks and slopes, flower borders and beds, garden edging and underplanting of roses and shrubs.
About
Phlox speciosa is a species of phlox known by the common name showy phlox. It is native to western North America from British Columbia to Arizona and New Mexico, where it occurs in sagebrush, pine woodlands, and mountain forests. It is an erect perennial herb with a shrubby base growing up to about 40 centimeters tall. The leaves are linear or lance-shaped, oppositely arranged, and generally glandular. In the garden it prefers full sun and most soil types. In UK gardens it is fully hardy throughout the UK (RHS H7). Suggested uses include cottage and informal garden, low maintenance, banks and slopes, flower borders and beds, garden edging and underplanting of roses and shrubs. It tolerates soil of any pH, moist but well-drained conditions and south-facing, west-facing and east-facing aspects.
Wikipedia contributors, CC BY-SA 4.0 — Phlox speciosa
Growing conditions
Best soil and position for Phlox
- Sunlight
- Full sun
- Soil type
- Sandy, Loamy, Clay
- Soil pH
- Acid, Alkaline, Neutral
- Soil moisture
- Moist but well-drained
- Aspect
- South-facing, West-facing, East-facing
- Exposure
- Exposed, Sheltered
- UK hardiness
- H7
Plant details
Phlox speciosa size, habit and characteristics
- Plant type
- Herbaceous Perennial
- Habit
- Clump forming, Matforming
- Foliage
- Deciduous, Evergreen
- Suggested uses
- Cottage and informal garden, Low Maintenance, Banks and slopes, Flower borders and beds, Garden edging, Underplanting of roses and shrubs
Care notes
Pruning and caring for Phlox speciosa
- Propagation
- Division in autumn or spring, Basal cuttings in spring, Root cuttings in early autumn or winter
- Pest resistance
- Stem and bulb eelworm, Phlox eelworm
- Disease resistance
- Powdery mildews, Grey moulds, Leafy gall, Leaf spot
Frequently asked questions
Where is the best place to plant Phlox speciosa?
Phlox speciosa prefers full sun. It suits exposed and sheltered positions.
What soil does Phlox speciosa need?
Phlox speciosa is adaptable and grows happily in most soil types, including sandy, loamy and clay. It is happy in soil of any pH. Aim for soil that stays moist but well-drained.
Is Phlox speciosa hardy in the UK?
Phlox speciosa has an RHS hardiness rating of H7, meaning it is fully hardy throughout the UK, tolerating temperatures below -20°C.
How do I propagate Phlox speciosa?
Division in autumn or spring, Basal cuttings in spring, Root cuttings in early autumn or winter.
More in the Phlox genus
- Phlox 'David'

- Phlox buckleyisword-leaf phlox

- Phlox caespitosatufted phlox

- Phlox douglasiiColumbia phlox

- Phlox hoodiispiny phlox
- Phlox paniculata 'Aida'

- Phlox paniculata 'Cherry Pink'

- Phlox paniculata 'Düsterlohe Zwerg'perennial phlox 'Düsterlohe Zwerg'
