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Madagascar periwinkle leaves turning yellow: causes and what to do

17 results in the diagnosis tree begin with yellowing leaves, 7 of them marked likely when the answers fit. They are ordered here for Madagascar periwinkle (Catharanthus roseus), using what its sources say about soil moisture, light, soil, watering and feeding and one problem recorded for it.

Sources last read 14 September 2026.

Start the diagnosis for this Madagascar periwinkle

Madagascar periwinkle (Catharanthus roseus), the whole plant.
Vinayaraj, CC BY-SA 4.0 · Wikimedia Commons

Catharanthus roseus, commonly known as bright eyes, Cape periwinkle, graveyard plant, Madagascar periwinkle, old maid, pink periwinkle, rose periwinkle, is a perennial species of flowering plant in the family Apocynaceae. It is native and endemic to Madagascar, but is grown elsewhere as an ornamental and medicinal plant, and now has a pantropical distribution. Wikipedia, CC BY-SA 4.0

Native range: E. & S. Madagascar (seasonally dry tropical). Also sold as Annual Vinca, Cape periwinkle, cayenne jasmine, East Indian periwinkle, old maid and Periwinkle.

What Madagascar periwinkle’s sources say that bears on this

Soil moisture
Moist but well-drained or Well-drained
RHS · read 13 September 2026
Light
Full sun
RHS · read 13 September 2026
Soil
Chalk, Loam, Sand; pH Acid or Alkaline or Neutral
RHS · read 13 September 2026
Watering
During growth, water moderately and feed monthly with a balanced liquid fertiliser. Give little water in winter.
RHS · read 13 September 2026
Feeding
While growing, water moderately and feed monthly with a balanced liquid fertiliser.
RHS · read 13 September 2026

How this shows up on a Madagascar periwinkle

Yellow, limp leaves at the base

The Madagascar periwinkle yellows from the base up. Affected leaves bend rather than snap, and the pot is still heavy several days after watering.

Soil described as moist but well-drained or well-drained is a drainage instruction as much as a watering one. Compost that stays saturated suffocates the fine roots that do the drinking.

Telling it apart: The soil, not the leaf. Wet compost under yellowing leaves points one way and dry compost the other, and the leaves alone will not tell you which.

RHS · read 13 September 2026

Possible causes, likeliest first for a Madagascar periwinkle

  1. Most likely not enough light

    Ranked higher for Madagascar periwinkle because of what its sources say.

    Its sources place this plant in full sun or high light, which makes a shortage of light a strong explanation indoors.

    • Full sun RHS · read 13 September 2026

    Why: Far from a bright window, a madagascar periwinkle builds leaves it cannot afford.

    What to try:

    • Move it closer to the brightest window you have, over a week or two rather than in one step.Useful: grow light
    • Water less while it is in low light; a madagascar periwinkle that is barely growing uses little.

    What would settle it: Compare a new leaf with one from last year. Smaller and paler, with a longer gap below it, is the reaching pattern rather than a nutrient one.

    Check this with the questions

  2. Most likely too little water

    • Moist but well-drained or Well-drained RHS · read 13 September 2026

    Why: Soil dry two inches down, under lower leaves that are yellowing or leaves that are falling, is a madagascar periwinkle shedding what it cannot support.

    What to try:

    • Water until it runs from the drainage hole, then let the pot drain.Useful: pot with drainage holes
    • If the water runs straight through a shrunken rootball, stand the pot in water for twenty minutes so the compost can take it up.

    What would settle it: Water it thoroughly and look again the same evening. A thirsty plant firms up fast. One that does not has a root problem rather than a water problem.

    Check this with the questions

  3. Most likely short of nutrients

    • Chalk, Loam, Sand; pH Acid or Alkaline or Neutral RHS · read 13 September 2026

    Why: Yellow between the veins with the veins still green is the classic pattern of a madagascar periwinkle running out of something it needs, and potting compost is largely spent after a year of watering.

    What to try:

    • Feed with a balanced houseplant fertiliser at the strength on its label, during the growing season.Useful: balanced liquid fertiliser
    • If it has been in the same compost for more than two years, repot into fresh compost in spring.Useful: well-draining potting mix

    What would settle it: Whether the oldest leaves went first. Nitrogen and magnesium move within the madagascar periwinkle, so it strips the old leaves to build the new ones. Damage that starts on new growth points at nutrients that do not move, such as iron, which often means the roots cannot take it up rather than that it is absent.

    Check this with the questions

Less likely for a Madagascar periwinkle, still possible

Questions

What usually causes yellowing leaves on a Madagascar periwinkle?
For Madagascar periwinkle: most likely not enough light, most likely too little water and most likely short of nutrients. Its sources place this plant in full sun or high light, which makes a shortage of light a strong explanation indoors.
How can I tell which one it is on my Madagascar periwinkle?
Where is the yellowing? The lowest leaves, working upward; New growth at the top, while older leaves stay green; Between the veins, the veins themselves still green; At the leaf tips and edges, browning as it goes; Patchy, only on the side facing the window.
What do Madagascar periwinkle's sources say about its soil moisture?
RHS: Moist but well-drained or Well-drained.
What does this look like on a Madagascar periwinkle?
The Madagascar periwinkle yellows from the base up. Affected leaves bend rather than snap, and the pot is still heavy several days after watering. Telling it apart: The soil, not the leaf. Wet compost under yellowing leaves points one way and dry compost the other, and the leaves alone will not tell you which.
Is Madagascar periwinkle 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 Madagascar periwinkle?

Everything the sources say about Madagascar periwinkle

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.