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Wax begonia 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 Wax begonia (Begonia semperflorens), using what its sources say about humidity, soil moisture and cold tolerance and one problem recorded for it.

Sources last read 13 September 2026.

Start the diagnosis for this Wax begonia

Native range: S. Brazil to NE. Argentina (seasonally dry tropical). Also sold as bedding begonia.

What Wax begonia’s sources say that bears on this

Humidity
ASHRAE recommends indoor relative humidity between 30% and 60%
Penn State Extension · read 13 September 2026
Soil moisture
Moist but well-drained or Well-drained
RHS · read 13 September 2026
Cold tolerance
H1C — 5–10°C
RHS · read 13 September 2026

How this shows up on a Wax begonia

Leaf tips go crisp and brown

A narrow dry border on the wax begonia, often with a faint yellow line against the healthy tissue. It appears on several leaves at once rather than spreading from one.

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: Look at the pot rim and the soil surface. A white crust points at a build-up from tap water or feed rather than at the air. Penn State also reports misting and pebble trays do little to the humidity around a plant.

Penn State Extension · read 13 September 2026

Possible causes, likeliest first for a Wax begonia

  1. Most likely too little water

    Ranked higher because Wax begonia's recorded problems point this way.

    • Moist but well-drained or Well-drained RHS · read 13 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

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

    • Clay, Loam, Sand; pH Acid or Neutral RHS · read 13 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 cold

    • H1C — 5–10°C RHS · read 13 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 wax begonia.
    • Leave damaged leaves until new growth appears, then remove the worst of them.

    What would settle it: Where the wax begonia 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

Less likely for a Wax begonia, still possible

Questions

What usually causes brown tips and edges on a Wax begonia?
For Wax begonia: most likely too little water, most likely a build-up of salts in the soil and most likely cold.
How can I tell which one it is on my Wax begonia?
Is the browning crisp and dry, or soft and dark? Crisp and dry; Soft and dark.
What do Wax begonia's sources say about its soil moisture?
RHS: Moist but well-drained or Well-drained.
What does this look like on a Wax begonia?
A narrow dry border on the wax begonia, often with a faint yellow line against the healthy tissue. It appears on several leaves at once rather than spreading from one. Telling it apart: Look at the pot rim and the soil surface. A white crust points at a build-up from tap water or feed rather than at the air. Penn State also reports misting and pebble trays do little to the humidity around a plant.
Is Wax begonia safe to handle while I check it?
Its sources list it as toxic to cats and dogs. Wash your hands after handling the roots or sap, and keep trimmings away from pets.

Something else wrong with the Wax begonia?

Everything the sources say about Wax begonia

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.