How to grow Garden phlox

Phlox paniculata · summer phlox

A hardy perennial with large, domed clusters of fragrant flowers from July to September, 0.6–1.2 m tall; a classic of summer borders that butterflies love.

Quick facts

Type	Flower
Family	Polemoniaceae
Light	Full sun
Frost	tolerates light frost
Soil for sowing	from 5 °C
Germination	14 days
Where it grows	Open ground

When to plant

It tolerates light frost: sow straight into the bed about three weeks before your last spring frost.

Frost dates · When to plant

Care

Open ground

Stage	Watering	Temperature	Feeding
Growth	every 7 days	—	balanced (NPK), at the start of the stage; balanced (NPK), 49 days into the stage
Flowering	every 7 days	—	—

Growing notes

Light

Best in full sun, at least 6 hours a day; it tolerates light shade, and some afternoon shade helps in hot summers.

Soil

Fertile, moist but well-drained soil rich in organic matter; it is not fussy about pH. It does poorly in soil that dries out.

Care

Plant or divide in early spring (or in autumn), at least 60 cm apart, and divide clumps every three or so years. Water in dry spells, at the base rather than over the leaves, and mulch to keep the roots cool. On poor soil give a general fertiliser in spring. Thin crowded clumps to 4–5 strong stems for air flow against powdery mildew, the commonest problem. Removing faded flower heads prolongs flowering. Cut the stems to the ground in late autumn or early spring and clear away old leaves.

Pests and diseases of Garden phlox

Two-spotted spider mite

Sources

Figures checked against these sources.