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Cuphea viscosissima

blue waxweed

A bushy, half-hardy annual with purple flowers produced over a long period from summer into autumn. The leaves and the stems are both sticky

Other common names

clammy cuphea
tarweed

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Ultimate height

0.1–0.5 metres

Time to ultimate height

1–2 years

Ultimate spread

0.5–1 metres

Chalk

Loam

Sand

Moisture

Well–drained

pH

Acid, Alkaline, Neutral

	Stem	Flower	Foliage	Fruit
Spring
Summer
Autumn
Winter

Full sun
Partial shade

Aspect

South–facing or West–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)

Botanical details

Family: Lythraceae
Native to GB / Ireland: No
Foliage: Evergreen
Habit: Spreading branched
Genus: Cuphea can be annuals, perennials or evergreen shrubs, often with sticky hairs, opposite, simple leaves and tubular flowers with a showy calyx and small petals
Name status: Correct

How to grow

Cultivation

Best grown in well-drained soil in a sheltered site in partial shade or full sun; it benefits from shading from hot sun

Propagation

Propagate by seed; ideally sow direct where plants are to flower

Suggested planting locations and garden types

Patio and container plants
City and courtyard gardens
Flower borders and beds
Wall side borders

Pruning

No pruning required

Pests

Generally pest-free

Diseases

Generally disease-free

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