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Bougainvillea brown leaf tips and edges: causes and what to do

6 results in the diagnosis tree begin with brown tips and edges, 3 of them marked likely when the answers fit. They are ordered here for Bougainvillea (Bougainvillea glabra), using what its sources say about humidity, soil moisture, cold tolerance, watering and feeding and one problem recorded for it.

Sources last read 14 September 2026.

Start the diagnosis for this Bougainvillea

Bougainvillea (Bougainvillea glabra), the whole plant.
পাপৰি বৰা, CC BY-SA 4.0 · Wikimedia Commons

Bougainvillea glabra, the lesser bougainvillea or paperflower, is the most common species of bougainvillea used for bonsai. The epithet 'glabra' comes from Latin and means "bald". Wikipedia, CC BY-SA 4.0

Native range: E. & S. Brazil (wet tropical). Also sold as Lesser Bougainvillea, Paper Flower and Paperflower.

What Bougainvillea’s sources say that bears on this

Humidity
ASHRAE recommends indoor relative humidity between 30% and 60%
Penn State Extension · read 11 September 2026
Soil moisture
Moist but well-drained
RHS · read 11 September 2026
Cold tolerance
H1C — 5–10°C
RHS · read 11 September 2026
Watering
Lesser Bougainvillea suits a hot, dry climate; water it thoroughly but let it dry out between waterings.
NC State Extension · read 13 September 2026
From spring, as plants resume active growth, water more and use a balanced liquid feed until colour shows in the bracts, then change to a high potassium feed. In autumn, water less and stop feeding.
RHS · read 13 September 2026
Feeding
From spring, as active growth resumes, water more and give a balanced liquid feed until colour shows in the bracts, then change to a high-potassium feed. In autumn, water less and stop feeding.
RHS · read 13 September 2026

How this shows up on a Bougainvillea

Crisp margins that appear in winter

The bougainvillea shows browning on many leaf blades at once, all at the margin, with no spots or soft patches anywhere.

Leaf margins are the end of the water supply, so they are the first tissue to run short when the air takes more than the roots can send. Penn State Extension cites 30% to 60% as the recommended indoor range, and a heated room in winter sits below it.

Telling it apart: Where the plant stands. Browning concentrated on the side facing a heater points at the air.

Penn State Extension · read 11 September 2026

Possible causes, likeliest first for a Bougainvillea

  1. Most likely cold

    Ranked higher because Bougainvillea's recorded problems point this way.

    • H1C — 5–10°C RHS · read 11 September 2026

    Why: Soft, dark patches rather than crisp ones are damaged tissue rather than dried tissue.

    What to try:

    • Move it away from the glass at night, or keep the curtain on the room side of the bougainvillea.
    • Leave damaged leaves until new growth appears, then remove the worst of them.

    What would settle it: Where the bougainvillea sits at night, and what the glass feels like at that hour. Damage that appeared after one cold night, on the side facing the window, is the pattern.

    Check this with the questions

  2. Most likely a build-up of salts in the soil

    • Loam; pH Acid or Alkaline or Neutral RHS · read 11 September 2026

    Why: Minerals from tap water and fertiliser are left behind as water evaporates, and a white crust on the compost or the pot rim is where they show.

    What to try:

    • Water slowly and heavily until several times the pot's volume has run through the drainage hole, to wash the salts out.Useful: pot with drainage holes
    • Scrape off the top layer of crusted compost and replace it.

    What would settle it: Scrape the crust. If it is gritty and dissolves in water it is mineral; if it is fluffy it is mould, which is a different problem.

    Check this with the questions

  3. Most likely too little water

    • Moist but well-drained RHS · read 11 September 2026

    Why: Soil dry two inches down leaves the roots nothing to send up, and the leaf edges are the last tissue in line.

    What to try:

    • Water thoroughly, until it runs from the drainage hole.Useful: pot with drainage holes
    • Check the soil with a finger every few days rather than watering on a fixed day.Useful: moisture meter

    What would settle it: Water it thoroughly and watch the next new leaves. If they come in with clean edges under steadier watering, the edges were thirst.

    Check this with the questions

Less likely for a Bougainvillea, still possible

Questions

What usually causes brown tips and edges on a Bougainvillea?
For Bougainvillea: most likely cold, most likely a build-up of salts in the soil and most likely too little water.
How can I tell which one it is on my Bougainvillea?
Is the browning crisp and dry, or soft and dark? Crisp and dry; Soft and dark.
What do Bougainvillea's sources say about its soil moisture?
RHS: Moist but well-drained.
What does this look like on a Bougainvillea?
The bougainvillea shows browning on many leaf blades at once, all at the margin, with no spots or soft patches anywhere. Telling it apart: Where the plant stands. Browning concentrated on the side facing a heater points at the air.

Something else wrong with the Bougainvillea?

Everything the sources say about Bougainvillea

What this does not cover

This page orders a decision tree's results using a plant's sourced care. It has not seen your plant, its pot or its window, and two problems at once are common: that is the usual reason a confident answer turns out wrong. The questions in the diagnosis tool narrow it further than a list can.