Overview
Callistemon viminalis 'Malawi Giant' is a bushy shrubs in the genus Callistemon, part of the Myrtaceae family, with evergreen foliage. Callistemon viminalis 'Malawi Giant' grows best in full sun, and tolerates most soils and acid and neutral pH. Its UK hardiness is rated H3. Suggested uses include city and courtyard gardens, mediterranean climate plants and patio and container plants.
About
Callistemon viminalis 'Malawi Giant' is an evergreen, well-branched shrub grown for its long summer display of bottlebrush flowers (June–September). It prefers full sun in a sheltered, south- or west-facing spot. Suits clay, loam or sandy soils provided they are well drained and not allowed to dry out completely. Classified H3 (borderline) in the UK, it is often used in containers or under glass for colder sites.
About the genus
Callistemon is a genus of shrubs in the family Myrtaceae, first described as a genus in 1814. The entire genus is endemic to Australia but widely cultivated in many other regions and naturalised in scattered locations. Their status as a separate taxon is in doubt, some authorities accepting that the difference between callistemons and melaleucas is not sufficient for them to be grouped in a separate genus.
Wikipedia contributors, "Callistemon", CC BY-SA 4.0 — Callistemon
In the garden
Callistemon viminalis 'Malawi Giant' belongs to the myrtle family (Myrtaceae) and is a cultivar within the Callistemon group. It originates from the bottlebrush lineage and is valued for its summer flowering period from June to September. Plants typically form a well-branched evergreen shrub, making them suitable where year-round foliage is wanted alongside a seasonal floral display. Position the shrub in full sun with shelter from prevailing winds, ideally on a south- or west-facing wall or in a courtyard where frost exposure is reduced. It tolerates clay, loam and sandy soils provided they are moist but well drained; a neutral to slightly acid pH is acceptable. The UK hardiness rating H3 equates to a borderline plant that benefits from the warm microclimates found near buildings or from winter protection such as a conservatory or greenhouse for the coldest winters. Use 'Malawi Giant' in town gardens, patios and containers or as part of a Mediterranean-style planting scheme. In containers choose a large pot and a free-draining ericaceous-capable mix, and site the pot where it receives strong sun yet remains sheltered. Where winters are colder, keep specimens against a warm wall or under cover so the summer bottlebrushes can be enjoyed between June and September.
Growing conditions
Best soil and position for Callistemon
- Sunlight
- Full sun
- Soil type
- Clay, Loam, Sand
- Soil pH
- Acid, Neutral
- Soil moisture
- Moist but well-drained, Well-drained
- Aspect
- South-facing, West-facing
- Exposure
- Sheltered
- UK hardiness
- H3
Plant details
Callistemon viminalis 'Malawi Giant' size, habit and characteristics
- Plant type
- Shrubs, Conservatory Greenhouse
- Habit
- Bushy
- Foliage
- Evergreen
- Suggested uses
- City and courtyard gardens, Mediterranean climate plants, Patio and container plants
Care notes
Pruning and caring for Callistemon viminalis 'Malawi Giant'
- Propagation
- Propagate by seed or from semi-hardwood cuttings
- Pest resistance
- May be susceptible to scale insect, mealy bug and glasshouse red spider mite
- Disease resistance
- May be susceptible to honey fungus
Frequently asked questions
Where is the best place to plant Callistemon viminalis 'Malawi Giant'?
Callistemon viminalis 'Malawi Giant' prefers full sun. It suits sheltered positions.
What soil does Callistemon viminalis 'Malawi Giant' need?
Callistemon viminalis 'Malawi Giant' is adaptable and grows happily in most soil types, including clay, loam and sand. It prefers acid and neutral soil. Aim for soil that stays moist but well-drained to well-drained.
Is Callistemon viminalis 'Malawi Giant' hardy in the UK?
Callistemon viminalis 'Malawi Giant' has an RHS hardiness rating of H3, meaning it is half-hardy, tolerating -5 to 1°C, and may need winter protection in colder areas.
How do I propagate Callistemon viminalis 'Malawi Giant'?
Propagate by seed or from semi-hardwood cuttings.