How to Grow African Blue Basil
Ocimum kilimandscharicum x basilicum
African Blue Basil is a sterile perennial hybrid, unlike all other basils which are annuals in the UK. Large shrubby plant (60-90cm) with purple-veined leaves, purple-blue flower spikes, and a camphor-clove scent. Excellent pollinator plant that flowers continuously from summer to frost. Cannot set seed so propagate only by cuttings. In the UK, grow in a large container and bring indoors before first frost. Overwinter in a bright, frost-free space. Cut back hard in spring for fresh vigorous growth.
Yearly Lifecycle
Care Essentials
Feed monthly with a balanced liquid fertiliser during the growing season. More vigorous than annual basils and benefits from regular feeding.
Watch For
- Aphids
- Whitefly
- Spider mites indoors
- Cold damage
Companions
Tomatoes, Peppers, Roses
Pet Safety
Care Requirements
Light
Full sun, warm and sheltered
Needs full sun for best growth and flowering. A south-facing, sheltered spot is ideal. Will tolerate light shade but flowers less.
Watering
Regular watering, allow surface to dry
Water regularly during the growing season but allow the surface to dry between waterings. Reduce watering significantly in winter when overwintering indoors.
Fertilizing
Monthly balanced feed during growth
Feed monthly with a balanced liquid fertiliser from spring to autumn. More vigorous than annual basils so needs more regular feeding to sustain growth.
Pruning
Hard prune in spring, trim throughout summer
Cut back hard in spring as new growth appears. Trim regularly through summer to maintain shape. Leave flower spikes for pollinators.
Winter protection
Bring indoors before frost, minimum 10°C
Not frost-hardy. Move indoors to a bright, frost-free location before first frost. Reduce watering over winter. Resume normal care in spring.
Growing Tips
Sterile hybrid — cuttings only
This is the only perennial basil for UK gardens. Cannot set seed — propagate exclusively by cuttings which root easily in water or compost.
Outstanding pollinator plant
Flowers continuously and is one of the best bee plants available. Leave flower spikes for pollinators rather than removing them.
Container for easy overwintering
Grow in a large container (minimum 30cm) so you can move it indoors before first frost. Cut back by half before overwintering.
Hard spring prune
Hard prune in spring as new growth appears. Responds well to cutting back and quickly fills out again.
Spacing & Planting
| Plant spacing | 60 cm |
| Row spacing | 60 cm |
| Mature height | 90 cm |
| Mature spread | 60 cm |
Large shrubby plant that spreads considerably. Give plenty of room for air circulation. In the UK, grow in a large container for easy overwintering indoors.
