Not the plant you're looking for? Search over 300,000 plants

Annual BiennialHerbs - Culinary

Ocimum basilicum 'Dark Opal'

basil 'Dark Opal'

A striking, upright, bushy annual producing stunning, dark purple, almost black, aromatic foliage that has a strong liquorice flavour. Attractive spikes of small, tubular, cerise red flowers appear in summer. Highly ornamental for warmer gardens in the UK, otherwise grow indoors under glass

Synonyms

Ocimum basilicum var. purpurascens 'Dark Opal'

Save to My plants

Buy this plant

Plant nurseries
2 suppliers

Ultimate height

0.1–0.5 metres

Time to ultimate height

1–2 years

Ultimate spread

0.1–0.5 metres

Loam

Sand

Moisture

Well–drained

pH

Acid, Alkaline, Neutral

	Stem	Flower	Foliage	Fruit
Spring
Summer
Autumn
Winter

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)

H1C

Botanical details

Family: Lamiaceae
Native to GB / Ireland: No
Foliage: Deciduous
Habit: Bushy
Genus: Ocimum can be aromatic annuals, evergreen perennials or shrubs with opposite, linear to broadly-ovate leaves and small tubular white or pinkish flowers in whorls forming a spike
Name status: Accepted

How to grow

Cultivation

Grow as an annual, indoors, in moist but well drained soil in a sheltered position in full sun. Can move outdoors in summer. Best grown in a container. See basil cultivation for more information

Propagation

Propagate by seed in gentle heat in spring under glass or indoors, or sow in-situ in summer. See sowing seeds indoors for further advice

Suggested planting locations and garden types

City and courtyard gardens
Mediterranean climate plants
Patio and container plants
Conservatory and greenhouse

Pruning

Pinch out flower heads as they appear to encourage continued leaf growth. If left to flower, cut back after flowering

Pests

May be susceptible to aphids, slugs, snails and leafhoppers

Diseases

May be susceptible to powdery mildews

Get involved

The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.