Petunia Amethyst Halo (Sweetunia Series)

RHS Plant Profile

petunia [Amethyst Halo]

RHS / Joanna Kossak

Annual Biennial Bedding

A compact, bushy, semi-trailing annual bearing a profusion of purple flowers edged with white from early summer into autumn

Position

Full sun

Soil Types

Loam, Sand

Max Height

0.1-0.5 metres

Max Spread

0.1-0.5 metres

Size

Time to Maturity: 1 year
Max Spread: 0.1-0.5 metres
Max Height: 0.1-0.5 metres

Growing Conditions

Loam Sand

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

Position

Full sun

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): H2

Colour & Scent

Season	Stem	Flower	Foliage	Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family: Solanaceae
Native to GB/Ireland: No
Foliage: Deciduous
Habit: Trailing
Genus: Petunia can be annuals or perennials, with simple leaves and large, solitary, trumpet-shaped flowers in the upper leaf axils from late spring to autumn
Name Status: Trade

How to Grow

Cultivation

Overwinter young plants under glass in frost free conditions and plant out after frosts have passed. Grow in light, well-drained soil in full sun, with shelter from drying winds

Propagation

Propagate by softwood cuttings in summer

Suggested planting locations and garden types

Coastal
Cottage and informal garden
City and courtyard gardens
Gravel garden
Patio and container plants
Banks and slopes
Flower borders and beds
Garden edging

Pruning

Deadhead regularly to prolong flowering

Pests

Aphids and slugs may be a problem

Diseases

May be susceptible to fungal foot rot and a virus