African flag (chasmanthe) Chasmanthe floribunda
African flag (chasmanthe) (Chasmanthe floribunda) is a deciduous perennial flowering plant in the Iridaceae family, native to Western Cape, South Africa. It grows 60 cm–1 m (24 in–3.3 ft) tall and 30–50 cm (12–20 in) wide, wants full sun and low water, and is hardy to about -4 °C (25 °F). Space plants about 30 cm (12 in) apart.
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African flag (chasmanthe) at a glance
| Type | Perennial flowering plant, deciduous |
|---|---|
| Family | Iridaceae |
| Mature height | 60 cm–1 m (24 in–3.3 ft) |
| Mature spread | 30–50 cm (12–20 in) |
| Spacing | 30 cm (12 in) centre to centre |
| Sun | Full sun, at least 5 h of direct sun a day |
| Water | Low; drought tolerance high, waterlogging tolerance none |
| Soil pH | 6–8 |
| Cold hardiness | About -4 °C (25 °F) once established (roughly USDA zone 9) |
| Heat stress | Likely above about 36 °C (97 °F) |
| Flowering | about 21–29 weeks after planting, for 4–6 weeks |
| Wind tolerance | Low |
| Pollinator value | High |
| Edible | Not grown as food |
| Native to | Western Cape, South Africa |
| Common in gardens of | 🇿🇦 South Africa, 🇺🇸 United States, 🇦🇺 Australia |
| Invasive in | California coastal scrub, south-western Australia: check local rules before planting |
Is African flag (chasmanthe) toxic?
- People: not known to be toxic
- Cats: not known to be toxic
- Dogs: not known to be toxic
Not known to be poisonous.
If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.
Companion planting: what to grow with African flag (chasmanthe)
No well-documented helpful pairing. Group it with plants that like full sun and low water.
Questions about African flag (chasmanthe)
- How far apart should I plant African flag (chasmanthe)?
- About 30 cm (12 in) apart, centre to centre. A mature plant spreads 30–50 cm (12–20 in).
- Does African flag (chasmanthe) need full sun?
- Full sun: at least 5 hours of direct sun a day.
- How much water does African flag (chasmanthe) need?
- Low water. Drought tolerance is high and waterlogging tolerance none.
- How cold-hardy is African flag (chasmanthe)?
- It tolerates about -4 °C (25 °F) once established, roughly USDA zone 9.
- When does African flag (chasmanthe) flower?
- About 21–29 weeks after planting, for 4–6 weeks.
- Is African flag (chasmanthe) poisonous to cats and dogs?
- For cats it is not known to be toxic; for dogs not known to be toxic; for people not known to be toxic. Not known to be poisonous.
- What grows well with African flag (chasmanthe)?
- There is no well-documented companion pairing for African flag (chasmanthe). Group it with plants that like the same sun (full sun) and water (low).
Sources and evidence
Evidence grade A (A: strong evidence).
- Plants of the World Online (taxonomy, native range), Royal Botanic Gardens, Kew
- PlantZAfrica, South African National Biodiversity Institute
- CABI Invasive Species Compendium, CABI
Notes and assumptions
- A summer-dry plant: water it through its first summer, then rarely or never; it wants sun, lean soil and sharp drainage, and is killed by summer irrigation and heavy clay more often than by drought.
- Fans of bright green leaves in winter and tall spikes of hooded orange-red tubular flowers in late winter, made for sunbirds. Summer-dormant. Spreads so readily from corms that it has naturalised in California and Australia.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
Related plants
- Bearded iris Iris germanica
- Japanese iris Iris ensata
- Siberian iris Iris sibirica
- Dutch crocus Crocus vernus
- Gladiolus Gladiolus x hortulanus
- Freesia Freesia refracta hybrids
- Montbretia (crocosmia) Crocosmia x crocosmiiflora
- African iris Dietes grandiflora