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Annual Biennial

Phlox '21st Century White'

phlox '21st Century White'

An upright annual with small, lance-shaped dark-green leaves and large clusters of white flowers with a subtle yellow eye for a long period of time in summer. Has long branching, wiry stems, very suited as a cut flower

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Ultimate height

0.5–1 metres

Time to ultimate height

1–2 years

Ultimate spread

0.5–1 metres

Chalk

Loam

Sand

Moisture

Well–drained, Moist but well–drained

pH

Acid, Neutral, Alkaline

	Stem	Flower	Foliage	Fruit
Spring
Summer
Autumn
Winter

Full sun
Partial shade

Aspect

West–facing or South–facing

Exposure

Exposed or Sheltered

Hardiness
Hardiness ratings
All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets
H1a: under glass all year (>15C)
H1b: can be grown outside in the summer (10 - 15)
H1c: can be grown outside in the summer (5 - 10)
H2: tolerant of low temperatures, but not surviving being frozen (1 to 5)
H3: hardy in coastal and relatively mild parts of the UK (-5 to 1)
H4: hardy through most of the UK (-10 to -5)
H5: hardy in most places throughout the UK even in severe winters (-15 to -10)
H6: hardy in all of UK and northern Europe (-20 to -15)
H7: hardy in the severest European continental climates (< -20)

Botanical details

Family: Polemoniaceae
Native to the UK: No
Foliage: Deciduous
Habit: Columnar upright
Genus: Phlox may be evergreen or herbaceous, mat-forming or erect perennials or shrubs, with simple leaves and salver-shaped flowers in terminal clusters
Name status: Accepted

How to grow

Cultivation

Will grow well in any fertile and well-drained soil preferably in full sun

Propagation

Propagate by seed in spring

Suggested planting locations and garden types

Cottage and informal garden
City and courtyard gardens
Patio and container plants
Flower borders and beds

Pruning

Cut back after flowering

Pests

May be susceptible to stem and bulb eelworm

Diseases

May be susceptible to Powdery mildews and leaf spot

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