Zonal geranium 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 Zonal geranium (Pelargonium zonale), using what its sources say about humidity, soil moisture and cold tolerance and one problem recorded for it.
Sources last read 14 September 2026.
Pelargonium zonale is a species of Pelargonium native to southern Africa in the western regions of the Cape Provinces, in the geranium family. It is one of the parents of the widely cultivated plant Pelargonium × hortorum, often called "geranium", "horseshoe geranium", "zonal geranium" or "zonal pelargonium". Wikipedia, CC BY-SA 4.0
Native range: Cape Prov. to KwaZulu-Natal (subtropical). Also sold as horseshoe geranium and zonal pelargonium.
What Zonal geranium’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
- Well-drainedRHS · read 13 September 2026
- Cold tolerance
- H1C — 5–10°CRHS · read 13 September 2026
How this shows up on a Zonal geranium
Brown tips on the newest leaves first
Leaves on the side of the zonal geranium nearest a heater or vent brown at the edges while those on the far side stay clean.
Dry air takes water from the leaf surface continuously, and the tissue at the edge is last in the queue for what the roots send up. Penn State Extension notes there is no single humidity figure that suits every indoor plant.
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 2026Possible causes, likeliest first for a Zonal geranium
Most likely too little water
Ranked higher because Zonal geranium's recorded problems point this way.
Its source describes well-drained soil for this plant, so soil that dries between waterings is expected. The concern is soil left dry long enough for the plant to go limp or wrinkle.
- 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.
Most likely a build-up of salts in the soil
- Loam, Sand; pH Acid or Alkaline 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.
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 zonal geranium.
- Leave damaged leaves until new growth appears, then remove the worst of them.
What would settle it: Where the zonal geranium 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.
Less likely for a Zonal geranium, still possible
Questions
- What usually causes brown tips and edges on a Zonal geranium?
- For Zonal geranium: most likely too little water, most likely a build-up of salts in the soil and most likely cold. Its source describes well-drained soil for this plant, so soil that dries between waterings is expected. The concern is soil left dry long enough for the plant to go limp or wrinkle.
- How can I tell which one it is on my Zonal geranium?
- Is the browning crisp and dry, or soft and dark? Crisp and dry; Soft and dark.
- What do Zonal geranium's sources say about its soil moisture?
- RHS: Well-drained.
- What does this look like on a Zonal geranium?
- Leaves on the side of the zonal geranium nearest a heater or vent brown at the edges while those on the far side stay clean. 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 Zonal geranium 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.
Other plants that show brown tips and edges
African violetBrown tips on the newest leaves first
Barberton daisyEdges of the leaves brown while the middle stays sound
Bearded irisLeaf tips go crisp and brown
Bigleaf hydrangeaDry, bruised edges after a cold, windy spell
Bird of paradiseCrisp margins that appear in winter
Blue passion flowerDry, bruised edges after a cold, windy spell
Something else wrong with the Zonal geranium?
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.