Commelina tuberosa Coelestis Group

RHS Plant Profile

dayflower Coelestis Group

RHS 2002

Other common names

blue spiderwort, day flower

Synonyms

Commelina coelestis

Herbaceous Perennial

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Coelestis Group are tuberous perennials which form a spreading clump of erect leafy stems, with vivid blue flowers in summer and autumn

Position

Full sun, Partial shade

Soil Types

Chalk, Loam, Sand

Max Height

0.5-1 metres

Max Spread

0.1-0.5 metres

Size

Time to Maturity: 2–5 years
Max Spread: 0.1-0.5 metres
Max Height: 0.5-1 metres

Growing Conditions

Chalk Loam Sand

Moisture: Well–drained
pH: Acid or Alkaline or Neutral

Position

Full sun Partial shade

Aspect: South–facing or North–facing or West–facing or East–facing
Exposure: 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): H3

Colour & Scent

Season	Stem	Flower	Foliage	Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family: Commelinaceae
Native to GB/Ireland: No
Foliage: Deciduous
Habit: Clump forming
Genus: Commelina can be annuals or perennials, forming mats or clumps with usually lance-shaped leaves and 3-petalled flowers emerging in succession from boat-like bracts
Name Status: Accepted

How to Grow

Cultivation

Grow in a fertile, well-drained soil in a warm, sheltered site in sun or partial shade. Provide a deep, dry winter mulch or in cold areas, lift plants and over winter in frost-free conditions

Propagation

Propagate by seed in spring, sown at 13-18°C or propagate by division in spring

Suggested planting locations and garden types

Cottage and informal garden
Flower borders and beds

Pruning

No pruning required

Pests

Generally pest-free

Diseases

Generally disease-free