Blue passion flower
Sources last read 14 September 2026.
Forgiving Among the more tolerant plants here.
Also called blue crown, Blue Passionflower, Bluecrown Passionflower, common passion flower, Common Passionflower, flower of five wounds, Flower of the Five Wounds, Passion flower, southern beauty and wild apricot.
Toxicity is partly unassessed
- Not assessed for cats. This plant is not on the ASPCA list. That is not a finding of safety: none of the sources read for this site gives an answer either way. Treat it as unknown.
- Not assessed for dogs. This plant is not on the ASPCA list. That is not a finding of safety: none of the sources read for this site gives an answer either way. Treat it as unknown.
- Not assessed for people. RHS publishes no harm statement for this plant. That is not a finding of safety: none of the sources read for this site gives an answer either way. Treat it as unknown.
What the sources say about its care
- Light
- Full sun, Partial shadeRHS · read 13 September 2026
- Water
- Moist but well-drained or Well-drainedRHS · read 13 September 2026
- Humidity
No source read publishes a humidity figure for any plant on this site. What follows is general guidance for foliage plants.
ASHRAE recommends indoor relative humidity between 30% and 60% 30–60%Penn State Extension · read 13 September 2026- Temperature
How cold this tolerates, not what it prefers. No source read for this site publishes a preferred range for a plant indoors.
H4 — -10 to -5°C -10 to -5 °CRHS · read 13 September 2026- Soil
- Chalk, Loam, Sand; pH Acid or Alkaline or NeutralRHS · read 13 September 2026
- Toxic to cats
- Not on the ASPCA list. That is not a finding of safety.ASPCA · read 13 September 2026
- Toxic to dogs
- Not on the ASPCA list. That is not a finding of safety.ASPCA · read 13 September 2026
- Harmful to people
- No statement of harm to people is published for this plant; that absence is not evidence it is safe.RHS · read 13 September 2026
How it usually goes wrong
- A thin dry rim that crumbles between the fingers
Tips first on a blue passion flower, then margins. Affected tissue is papery and slightly curled, and the damage stops rather than advancing once conditions change.
Heated air holds less water than the plant loses into it, so moisture leaves the leaf faster than it arrives. Penn State Extension cites ASHRAE's indoor range of 30% to 60% relative humidity, and winter heating often takes a room below it. That applies while it is grown indoors; its RHS rating of H4 describes a plant that also grows outside, where the air is seldom that dry.
Telling it apart: Whether the soil is dry too. Crisp edges with damp soil point at the air; with dry soil, at the watering.
Penn State ExtensionBlue passion flower leggy, leaning growth: causes- Bleached patches on the side facing the glass
On a blue passion flower the scorch appears within a few days of a sunny spell or a move, and it does not spread afterward.
Glass concentrates what would be tolerable outdoors, because it holds the heat and removes the moving air that carried it away. Its source describes full sun, partial shade.
Telling it apart: Whether it followed a move or a season. Scorch appears within days of a change in position.
RHSDiagnose spots on the leaves on this Blue passion flower- Dry, bruised edges after a cold, windy spell
After a windy spell the blue passion flower shows dry brown edges and torn leaves on its exposed side. New growth that follows is undamaged if the weather settles.
RHS describes it as needing shelter. Moving air dries leaf surfaces quickly and bruises soft tissue, so a plant in a windy spot is marked on the side the wind reaches.
Telling it apart: Whether it followed stormy weather. Damage that appeared overnight after wind is weather; damage that develops over weeks is something else.
RHSDiagnose brown tips and edges on this Blue passion flower- Leaves but no flowers
The blue passion flower flowered well at first, then less each season, while its leaves stayed healthy and new stems grew longer.
Its source places it in full sun, partial shade. Flowers cost more than leaves, and a plant kept darker than that keeps growing leaves while it builds few buds or none.
Telling it apart: The rest of the plant. A healthy, leafy plant without flowers is short of light or of a season it needs; a plant that is also yellowing has a root or water problem first.
RHSDiagnose no flowers or dropped buds on this Blue passion flower- Soft, sagging leaves low on the plant in soil that has not dried
The lowest leaves of the blue passion flower go yellow and translucent at the stalk and drop with a light pull, while the compost stays wet.
A pot that does not dry between waterings keeps the roots in water rather than in damp soil, and the leaves above them yellow for want of what those roots can no longer send up.
Telling it apart: Two inches down with a finger. Above the soil, drowning and thirst look the same; below it they are opposites.
RHSDiagnose drooping on this Blue passion flower
Not sure which it is? Ask the diagnosis questions for Blue passion flower.
Routine care
- Propagation
- Seed or stem cuttings can be used for propagation.NC State Extension · read 13 September 2026Sow seed, take semi-hardwood cuttings, or layer in spring or autumn.RHS · read 13 September 2026
- Pruning
- It reaches 10 to 40 feet tall with a spread of 3 to 6 feet; pruning after flowering can reduce its size. Cut the current year's growth back by half.NC State Extension · read 13 September 2026Pruning group 11 or 12 in early spring, if needed.RHS · read 13 September 2026
- Pests and diseases
- Can be troubled by barnacle scale, plus the phlox plant bug and related Lopidea plant bugs.NC State Extension · read 13 September 2026Under glass, scale insects, mealybugs, glasshouse whitefly and glasshouse red spider mite can occur. Diseases: a virus and, rarely, honey fungus.RHS · read 13 September 2026
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Photographs
About the plant
Passiflora caerulea, the blue passionflower, bluecrown passionflower or common passion flower, is a species of flowering plant in the family Passifloraceae. It is native to South America and has been introduced elsewhere.
From Wikipedia, CC BY-SA 4.0 · read 13 September 2026
- Native range
- Bolivia to Brazil and N. ArgentinaWorld Checklist of Vascular Plants, June 2026 release, CC BY.Kew WCVP · read 13 September 2026Bolivia to Brazil and N. ArgentinaNC State Extension · read 13 September 2026S AmericaRHS · read 13 September 2026
- Climate
- subtropicalWorld Checklist of Vascular Plants, June 2026 release, CC BY.Kew WCVP · read 13 September 2026
- Growth form
- Herbaceous Perennial, Perennial, Vine; habit climbingNC State Extension · read 13 September 2026Climbing (evergreen)RHS · read 13 September 2026
- Size
- Height 120–480 in; width 36–72 inNC State Extension · read 13 September 2026Height 8-12 metres; spread 2.5-4 metres after 5–10 yearsRHS · read 13 September 2026
- Flowering
- Flowers blue, pink, white; blooms in fall, summerNC State Extension · read 13 September 2026Flowers blue in summer and autumn; purple in summer and autumn; white in summer and autumnRHS · read 13 September 2026
- Uses
What sources record people using this plant for. A traditional or medicinal use listed here is a record of use, not advice to eat it or treat anything with it.
Parts of the plant make a tea taken to relieve stress. The fruit is edible but has little flavor.NC State Extension · read 13 September 2026
Common problems with Blue passion flower
Plants with similar care
Bush lilyDry, curled edges on leaves near a heater
Dog roseEdges of the leaves brown while the middle stays sound
English lavenderBuds form and fall before they open
Flaming KatyA thin dry rim that crumbles between the fingers
Hardy fuchsiaBrown, papery patches on the leaves nearest the glass
HyacinthFlowering stops while the foliage carries on
Sources
- ASPCA · read 13 September 2026
- Kew WCVP · read 13 September 2026
- NC State Extension · read 13 September 2026
- Penn State Extension · read 13 September 2026
- RHS · read 13 September 2026
- Wikipedia · read 13 September 2026
What this does not cover
The figures above are what published sources say, not measurements of the plant in your room. They say nothing about your pot size, your water, the season, or how far from the glass the plant stands, and those decide more than any figure here does.
Humidity has no species figure because no source read for this site publishes one, and the only temperature published for this plant is a cold floor. The simulator fills those gaps with general figures for its kind of plant, marked as general and listed on how we read sources. Where a toxicity row says the plant was not assessed, that is the absence of a finding and not a finding of safety.
If something is already wrong, the diagnosis tool asks about the soil, the window and the watering, which is where the answer usually is.