Why Plants Die
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Jacaranda

Jacaranda mimosifolia, Bignoniaceae

Sources last read 14 September 2026.

Difficult One of the harder ones, and one of the reasons the diagnosis tool exists.

Also called black poui.

Jacaranda (Jacaranda mimosifolia), the whole plant.
Wadakuramon, CC0 · Wikimedia Commons

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 shade
RHS · read 13 September 2026
Water
Well-drained
RHS · 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.

H1C — 5–10°C 5–10 °C
RHS · read 13 September 2026
Soil
Chalk, Clay, Loam, Sand; pH Acid or Alkaline or Neutral
RHS · 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

Brown brittle margins with a green centre

On a jacaranda the browning starts furthest from the midrib and works inward, and it crumbles rather than smears. The centre of each leaf is untouched.

Transpiration rises as the air dries, and the tissue furthest from a vein loses first. Penn State Extension notes there is no single humidity figure that suits every indoor plant, which is why this site publishes a range rather than a number.

Telling it apart: When it started. Edges that browned as the heating came on point at air; edges that browned through a wet summer do not.

Penn State ExtensionDiagnose brown tips and edges on this Jacaranda
The canopy goes limp and the compost shrinks from the pot

The jacaranda loses its stiffness first at the tips of the newest growth, and the whole pot feels light for its size.

With well-drained soil taken past dry, there is nothing left for the roots to move, and the plant gives up its shape before it gives up its colour.

Telling it apart: The weight of the pot. Light and sagging is thirst; heavy and sagging is not.

RHSDiagnose drooping on this Jacaranda
Whitened areas where the sun falls longest

The jacaranda shows pale, dry patches only where direct sun reaches, often with a sharp edge between damaged and healthy tissue.

Sun through a window on a still day heats a leaf far above the air around it. Its source describes full sun, partial shade; the glass adds the heat that does the damage.

Telling it apart: The edge of the damage. Scorch has a sharp boundary; rot and infection have a soft, spreading one.

RHSDiagnose leaf drop on this Jacaranda

Not sure which it is? Ask the diagnosis questions for Jacaranda.

Routine care

Propagation
Seed, stem cuttings
NC State Extension · read 13 September 2026
Increase from seed or semi-ripe cuttings.
RHS · read 13 September 2026
Pruning
Prune lightly; see pruning group 1.
RHS · read 13 September 2026
Pests and diseases
Usually free of pests and diseases.
RHS · read 13 September 2026

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About the plant

Jacaranda mimosifolia is a sub-tropical tree native to south-central South America that has been widely planted elsewhere because of its attractive and long-lasting violet-colored flowers. It is also known as the jacaranda, blue jacaranda, Nupur or black poui. Older sources call it J. acutifolia, but modern authorities usually classify it as J. mimosifolia.

From Wikipedia, CC BY-SA 4.0 · read 13 September 2026

Native range
Bolivia to NW. Argentina
World Checklist of Vascular Plants, June 2026 release, CC BY.
Kew WCVP · read 13 September 2026
Bolivia, Paraguay, and northern Argentina
NC State Extension · read 13 September 2026
South America
RHS · read 13 September 2026
Climate
subtropical
World Checklist of Vascular Plants, June 2026 release, CC BY.
Kew WCVP · read 13 September 2026
Growth form
tree
World Checklist of Vascular Plants, June 2026 release, CC BY.
Kew WCVP · read 13 September 2026
Perennial, Tree; habit ascending, erect, irregular
NC State Extension · read 13 September 2026
Columnar upright (deciduous)
RHS · read 13 September 2026
Size
Height 300–600 in; width 180–300 in
NC State Extension · read 13 September 2026
Height Higher than 12 metres; spread wider than 8 metres after 10–20 years
RHS · read 13 September 2026
Flowering
Flowers blue, purple/lavender; blooms in spring
NC State Extension · read 13 September 2026
Flowers blue in spring and summer; purple in spring and summer
RHS · 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.

Used for medicine, fuel and wood.
NC State Extension · read 13 September 2026

Plants with similar care

Sources

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.