Overview
Exacum is a plant with a bushy habit in the genus Exacum, part of the Gentianaceae family, with evergreen foliage. Exacum grows best in full sun, and tolerates loam soils and neutral pH. Its UK hardiness is rated H1c. Suggested uses include patio and container plants and flower borders and beds.
About
Exacum is an evergreen, compact and well-branched member of the Gentianaceae grown for its summer flowering. It prefers a south-facing, sheltered site in full sun with neutral, moist loam. Classed H1c (tender), it is not frost-hardy and is best used in pots or locations where it can be protected over winter.
In the garden
Exacum is a genus in the Gentianaceae native to tropical regions including parts of Africa, the Arabian peninsula, South and Southeast Asia, New Guinea and Australia. In temperate Britain it is grown for its summer display and evergreen foliage, and many gardeners treat it as a tender ornamental suited to warm, sheltered spots. Plant into a freely draining loam at neutral pH and keep soil consistently moist without allowing the rootplate to sit in water. Give a south-facing, sheltered aspect in full sun; exposed sites reduce flowering and can stress the foliage. As an H1c plant it requires frost-free conditions through winter, so containers are useful because they can be moved under cover when temperatures fall. Use Exacum in patio pots, window boxes or the front of a sunny, sheltered flower border where its compact, well-branched form can be appreciated. Its summer flowering period runs from June to September, making it a reliable source of seasonal colour when placed where it receives direct sun and protection from cold winds.
Growing conditions
Best soil and position for Exacum
- Sunlight
- Full sun
- Soil type
- Loam
- Soil pH
- Neutral
- Soil moisture
- Moist
- Aspect
- South-facing
- Exposure
- Sheltered
- UK hardiness
- H1c
Plant details
Exacum size, habit and characteristics
- Habit
- Bushy
- Foliage
- Evergreen
- Suggested uses
- Patio and container plants, Flower borders and beds
Care notes
Pruning and caring for Exacum
- Propagation
- Seed sown in early spring at 18-20°C
- Pest resistance
- Generally pest-free
- Disease resistance
- Generally disease-free
Frequently asked questions
Where is the best place to plant Exacum?
Exacum prefers full sun. It suits sheltered positions.
What soil does Exacum need?
Exacum grows best in loam soil. It prefers neutral soil. Aim for soil that stays moist.
Is Exacum hardy in the UK?
Exacum has an RHS hardiness rating of H1c, meaning it needs a warm, frost-free position of 5–10°C and is best grown under glass in the UK.
How do I propagate Exacum?
Seed sown in early spring at 18-20°C.