Phlox paniculata (perennial phlox) — Clump forming

Overview

Phlox paniculata is a clump forming perennial in the genus Phlox, part of the Polemoniaceae family, with deciduous foliage. It typically grows around 1.2 m tall. Phlox paniculata grows best in full sun, and tolerates most soils and any pH. Its UK hardiness is rated H7. Suggested uses include borders, cut flowers and cottage gardens. It is native to Eastern USA.

About

Phlox paniculata is a perennial that bears strongly fragrant flower heads and typically reaches around 1.2 m. Flowering occurs from June to September, offering an extended summer display. It suits full sun and moist but well-drained soils and is often grown in borders and cottage gardens.

Wikipedia contributors, CC BY-SA 4.0 — Phlox paniculata

About the genus

Phlox is a genus of 68 species of perennial and annual plants in the family Polemoniaceae. They are found mostly in North America in diverse habitats from alpine tundra to open woodland and prairie. Some flower in spring, others in summer and fall.

Wikipedia contributors, "Phlox", CC BY-SA 4.0 — Phlox

In the garden

Phlox paniculata originates from the eastern United States and has long been grown in temperate gardens for its scented summer blooms. Plants typically reach about 1.2 m and produce a succession of flowers between June and September, making them useful where a prolonged display is wanted. Give it a sunny position with soil that retains moisture yet drains freely; it performs on sandy, loamy or clay soils provided they are not waterlogged. In UK terms it is H7 — fully hardy — so it will survive winter outdoors without routine protection. The USDA hardiness range (4–9) reflects the species’ tolerance of a broad climatic span. Use Phlox paniculata along mixed borders where its height and flowering period complement lower perennials, or grow it specifically for cutting: the fragranced blooms suit vases and bouquets. Allow enough room for air to move through plants to reduce damp around the base in wet weather. Flowering from June to September, its scented stems make a practical choice for bringing summer scent inside.

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: Full sun
UK hardiness: H7

Plant details

Phlox paniculata size, habit and characteristics

Plant type: Perennial
Habit: Clump forming
Foliage: Deciduous
Height: 1.2 m
Suggested uses: Borders, Cut flowers, Cottage gardens
Native to: Eastern USA
Fragrance: Flower

Care notes

Pruning and caring for Phlox paniculata

Cultivation: Prefers moist, well-drained soil; mulch to retain moisture; avoid overcrowding to reduce mildew
Pruning: Deadhead spent flowers to encourage reblooming; cut back after flowering to maintain shape
Propagation: Division, Cuttings, Seed
Pest resistance: Phlox eelworm
Disease resistance: Powdery mildews, Grey moulds, Leafy gall, Leaf spot

Frequently asked questions

How do I grow Phlox paniculata?

Prefers moist, well-drained soil; mulch to retain moisture; avoid overcrowding to reduce mildew.

Where is the best place to plant Phlox paniculata?

Phlox paniculata prefers full sun. It suits full sun positions.

What soil does Phlox paniculata need?

Phlox paniculata 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.

How do I prune Phlox paniculata?

Deadhead spent flowers to encourage reblooming; cut back after flowering to maintain shape.

How big does Phlox paniculata grow?

Phlox paniculata reaches a height of 1.2 m.

Is Phlox paniculata hardy in the UK?

Phlox paniculata 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 paniculata?

Division, Cuttings, Seed.

More in the Phlox genus

Browse all Phlox →