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 4.0Phlox 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

Browse all Phlox