Gelsemium rankinii

RHS Plant Profile

Rankin's swamp trumpet flower

Conservatory Greenhouse Climber Wall Shrub

Buy this from Plant Nurseries
1 Suppliers

A vigorous twining evergreen perennial to up to 6m, with slender twining stems bearing glossy green narrowly ovate leaves and small clusters of funnel-shaped, bright yellow flowers marked with orange in throat

Position

Full sun, Partial shade

Soil Types

Chalk, Clay, Loam, Sand

Max Height

4-8 metres

Max Spread

1.5-2.5 metres

Size

Time to Maturity: 5–10 years
Max Spread: 1.5-2.5 metres
Max Height: 4-8 metres

Growing Conditions

Chalk Clay Loam Sand

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

Position

Full sun Partial shade

Aspect: South–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: Gelsemiaceae
Native to GB/Ireland: No
Foliage: Evergreen
Habit: Climbing
Potentially harmful: Harmful if eaten. Wear gloves and other protective equipment when handling Pets (poultry): Harmful if eaten. For further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants
Genus: Gelsemium are twining evergreen perennials with simple, paired leaves and fragrant, funnel-shaped flowers that maybe solitary or in small clusters in spring and summer
Name Status: Correct
Plant Range: USA

How to Grow

Cultivation

Grow under glass in a peat-free, loam-based potting compost in full or bright filtered light with shade from hot sun. Water freely when in growth applying a balanced liquid fertiliser monthly. Water sparingly in winter. Can be grown outdoors in milder areas in most moderately fertile soils but will require protection from cold drying winds

Propagation

Propagate by seed sown at 13 to 18°C in spring or take semi-hardwood cuttings with bottom heat in summer

Suggested planting locations and garden types

City and courtyard gardens
Climber and wall shrubs
Conservatory and greenhouse
Wall side borders

Pruning

Pruning group 12, after flowering

Pests

May be susceptible to glasshouse whitefly

Diseases

Generally disease-free