Blue passion flower Passiflora caerulea
Blue passion flower (Passiflora caerulea) is an evergreen perennial flowering plant in the Passifloraceae family, native to South America (Argentina, Paraguay, southern Brazil). It grows 3–8 m (10–26 ft) tall and 2–5 m (6.6–16 ft) wide, wants full sun and moderate water, and is hardy to about -12 °C (10 °F). Space plants about 2 m (6.6 ft) apart.
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Blue passion flower at a glance
| Type | Perennial flowering plant, evergreen |
|---|---|
| Family | Passifloraceae |
| Mature height | 3–8 m (10–26 ft) |
| Mature spread | 2–5 m (6.6–16 ft) |
| Spacing | 2 m (6.6 ft) centre to centre |
| Sun | Full sun, at least 6 h of direct sun a day |
| Water | Moderate; drought tolerance moderate, waterlogging tolerance low |
| Soil pH | 6–7.5 |
| Cold hardiness | About -12 °C (10 °F) once established (roughly USDA zone 8) |
| Heat stress | Likely above about 35 °C (95 °F) |
| Flowering | from about June for 13–17 weeks (northern hemisphere; later in cold climates, earlier in warm ones) |
| Wind tolerance | Low |
| Pollinator value | Moderate |
| Edible | Yes: ripe fruit pulp (bland) |
| Native to | South America (Argentina, Paraguay, southern Brazil) |
| Common in gardens of | 🇧🇷 Brazil, 🇬🇧 United Kingdom |
Is Blue passion flower toxic?
- People: mildly toxic
- Cats: not well documented
- Dogs: not well documented
- Parts: leaves, unripe fruit, stems
Plant parts contain cyanogenic glycosides; ripe fruit pulp is edible but unripe fruit and leaves are not.
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 Blue passion flower
No well-documented helpful pairing. Group it with plants that like full sun and moderate water.
Questions about Blue passion flower
- How far apart should I plant Blue passion flower?
- About 2 m (6.6 ft) apart, centre to centre. A mature plant spreads 2–5 m (6.6–16 ft).
- Does Blue passion flower need full sun?
- Full sun: at least 6 hours of direct sun a day.
- How much water does Blue passion flower need?
- Moderate water. Drought tolerance is moderate and waterlogging tolerance low.
- How cold-hardy is Blue passion flower?
- It tolerates about -12 °C (10 °F) once established, roughly USDA zone 8.
- When does Blue passion flower flower?
- From about June for 13–17 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
- Is Blue passion flower poisonous to cats and dogs?
- For cats it is not well documented; for dogs not well documented; for people mildly toxic. Plant parts contain cyanogenic glycosides; ripe fruit pulp is edible but unripe fruit and leaves are not.
- What grows well with Blue passion flower?
- There is no well-documented companion pairing for Blue passion flower. Group it with plants that like the same sun (full sun) and water (moderate).
Sources and evidence
Evidence grade C (C: plausible, mixed evidence).
- RHS Plant Finder, Royal Horticultural Society
- Plants For A Future database, PFAF
- Plants of the World Online (taxonomy, native range), Royal Botanic Gardens, Kew
Notes and assumptions
- Typical garden-form values; cultivars and local conditions differ.
- Semi-evergreen; cuts back to the ground in hard frost and regrows. Tendril climber that suckers freely; fruit is only set in warm summers. Can naturalise in mild climates.
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
- Passion fruit Passiflora edulis
- Sweet granadilla Passiflora ligularis
- Banana passionfruit (curuba) Passiflora tripartita
- Giant granadilla (badea) Passiflora quadrangularis
- Sunflower Helianthus annuus
- French marigold Tagetes patula
- English lavender Lavandula angustifolia
- Zinnia Zinnia elegans