Clematis heracleifolia 'Cassandra' (H) | tube clematis 'Cassandra'

RHS

Synonyms

Clematis tubulosa 'Cassandra'

Herbaceous Perennial

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A deciduous sub-shrub to around 1m tall with toothed,dark green leaves up to 13cm long and wide. Clusters of strongly fragrant, deep blue, tubular flowers to 4cm across with recurved petal tips are borne in summer

Position

Full sun

Soil Types

Chalk, Clay, 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 Clay Loam Sand

Moisture: Moist but well–drained or Well–drained
pH: Acid or Alkaline or Neutral

Position

Full sun

Aspect: South–facing or West–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): H5

Colour & Scent

Fragrance Flower

Season	Stem	Flower	Foliage	Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family: Ranunculaceae
Native to GB/Ireland: No
Foliage: Deciduous
Habit: Bushy
Potentially harmful: Skin irritant. Wear gloves and other protective equipment when handling. Pets (rabbits): Harmful if eaten. For further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants
Genus: Clematis can be deciduous or evergreen shrubs or herbaceous perennials, mostly climbing by twining leaf-stalks, and often with showy flowers. Some have attractive fluffy seedheads in autumn
Name Status: Accepted
Horticultural Group

Horticultural Classification Codes

Horticultural Classification Codes are often given to genera which have a large number of species or cultivars. They are used to categorise cultivated plants based on specific, shared characteristics such as shape, colour, size or flowering time, and can be displayed as letters or numbers

For example:
Dahlia ‘Sunset Kate (Sin) = Single flower
Rosa ‘Marigold’ (HT) = Hybrid Tea: Heracleifolia Group consists of deciduous, woody-based sub-shrubs with erect or climbing stems, sometimes herbaceous, ternate or pinnate leaves, and narrowly bell-shaped or starry flowers on the current year's growth in summer and autumn

How to Grow

Cultivation

Plant in a moisture-retentive, well-drained soil. Keep the base of the plant and roots cool and shaded by other plants or a layer of pebbles or flat stones at the base. Plant with the crown of the clematis at soil level. Mulch in late winter with garden compost or well-rotted manure, avoiding the immediate crown. Ideal for a border where it can be supported by other plants. See clematis cultivation for more advice

Propagation

Propagate by division in spring.

Suggested planting locations and garden types

Cottage and informal garden
Wildlife gardens
Flower borders and beds

Pruning

Pruning (Clematis) Group 3

Pests

May be susceptible to aphids, snails and caterpillars; petals may be eaten by earwigs

Diseases

May be susceptible to honey fungus (rarely), clematis wilt and clematis slime flux