Lobelia richardsonii hort.

RHS Plant Profile

Richardson lobelia

RHS

Synonyms

Lobelia erinus 'Richardii'

Annual Biennial Bedding

A bushy evergreen perennial with lax trailing shoots, to 10cm tall, with narrow, dark green leaves and 2-lipped, white-throated sky blue flowers in the upper leaf axils

Position

Full sun, Partial shade

Soil Types

Loam

Max Height

Up to 10 cm

Max Spread

0.1-0.5 metres

Size

Time to Maturity: 1–2 years
Max Spread: 0.1-0.5 metres
Max Height: Up to 10 cm

Growing Conditions

Loam

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

Position

Full sun Partial shade

Aspect: South–facing or East–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: Campanulaceae
Native to GB/Ireland: No
Foliage: Evergreen
Habit: Trailing
Potentially harmful: Harmful if eatenskin irritant. Wear gloves and other protective equipment when handling Wear gloves and other protective equipment when handling. Pets: Harmful if eatenskin irritant. For further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants
Genus: Lobelia can be annuals, perennials or shrubs, with simple leaves and showy 2-lipped flowers that may be solitary or in racemes or panicles
Name Status: Correct

How to Grow

Cultivation

Grow in deep, fertile, reliably moist soil in full sun or partial shade. Apply a balanced liquid fertiliser every 2 weeks in spring and early summer and then a high potash fertiliser from midsummer onwards. In containers, use a peat-free multipurpose compost

Propagation

Propagate by seed at 13-18°C in late winter

Suggested planting locations and garden types

City and courtyard gardens
Coastal
Cottage and informal garden
Patio and container plants
Flower borders and beds

Pruning

No pruning required

Pests

May be susceptible to slugs

Diseases

Generally disease-free