How to Grow Poinsettia and Make It Turn Red Again Every Winter
A poinsettia turns red because of darkness, not fertiliser. To grow poinsettia that colours up again, give it full sun by day and 14 hours of unbroken darkness every night for 8 to 10 weeks from early October. One streetlight or tube light through the window and the leaves stay green.
Quick facts
- Colour season: December to February
- Dark treatment: 14 hours of total darkness nightly, early October to early December
- Pot: 8 to 12 inches (5 to 15 litres); in the ground it becomes a 2 to 3 metre shrub in Karachi and Lahore
- Sun: 6 hours or more
- Cuttings: April to June, or from the March pruning
- Prune: March, after colour fades; last pinch by end of August
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Why is my poinsettia not turning red?
The red “flowers” are bracts, coloured leaves. The real flowers are the small yellow beads in the middle. Bracts change colour only when nights are long and dark for weeks. Clemson’s extension service gives the routine: from the first week of October, keep the plant in total darkness for 14 continuous hours a night for 8 to 10 weeks, with 6 to 8 hours of bright sun in the day.
Outdoors in a garden with no lights, autumn does this for free. That is why the big poinsettia shrubs in old Karachi and Lahore bungalows blaze red every December. A pot on a lit city balcony, or indoors near a lamp, never gets a true night.
- From about 1 October, at 6 pm, cover the plant with a thick cardboard box or put it in an unused cupboard.
- Uncover at 8 am and put it in full sun.
- Do this every single night. Even one evening of light can delay colour.
- Keep watering and feeding normally. Colour shows within about 8 weeks.
- Stop once the bracts are fully coloured, usually early December.
Use the darkest room you have
A box over the pot is easy to forget. Many people have better luck putting the pot in a store room or a bathroom that nobody switches on at night, carrying it out every morning. Check for light leaks under the door by standing inside at night.
Where does poinsettia grow best in Pakistan and North India?
| Zone | Pot or ground | Watch for |
|---|---|---|
| Coastal (Karachi, Mumbai) | Both; thrives in the ground | Overwatering in humid weeks |
| Punjab plains (Lahore, Delhi) | Ground in a sheltered corner, or pot | Frost nights in Dec to Jan |
| Hot dry (Multan, Bahawalpur) | Pot you can move | Leaf scorch in 45C afternoons |
| Sub-humid (Islamabad, Peshawar) | Pot, protected | Colder winters; bring in on frost nights |
| Hills | Indoor pot only | Frost kills it |
How do you care for a poinsettia through the year?
Soil: 2 parts garden soil, 1 part compost, 1 part sand or cocopeat. Drainage is non-negotiable; see the potting mix guide.
Water: when the top 3 cm is dry. Nursery plants bought in December often sit in a foil wrap full of water; tear the bottom of the foil. Daily light watering in May and June on a hot roof; much less from November. The seasonal watering guide helps.
Feed: balanced liquid fertiliser at label strength every 3 to 4 weeks from April to October. Stop when bracts colour. Compost top-dressing in spring.
When should you prune poinsettia, and what if you prune late?
Cut it back in March, when the bracts fade, to about 20 cm high (Clemson suggests roughly 8 inches for pots). Pinch new tips in May to June to make it bushy. Clemson’s rule is no pinching after 1 September.
Prune or pinch in September or October and you remove the shoots that would have carried this year’s colour; the plant goes into winter with green tips only. Garden shrubs in Karachi can take a heavier cut in March to keep them from going leggy.
How do you propagate poinsettia?
Stem cuttings are the practical route; seed is rarely available and gives unpredictable plants.
- In April to June, cut 10 cm soft tips with 3 or 4 leaves. Wear gloves; milky sap oozes.
- Dip the cut end in water briefly to stop the sap, or wipe it.
- Remove lower leaves and plant 3 cm deep in damp cocopeat and sand.
- Keep in bright shade and humid air (a clear bottle cut in half over the pot works).
- Roots in about 4 weeks. Pot up when new leaves appear.
A cutting rooted in May can colour in its first December if you give it the dark treatment.
Why are poinsettia leaves turning yellow and falling?
- Cold draught or frost: sudden leaf drop. Move it inside on nights near zero.
- Waterlogged roots: yellow lower leaves, soft stems. Fix drainage.
- Sudden move: nursery to dim room; some drop is normal, then it settles.
- Whitefly and mealybug: sticky leaves, white fluff. Hose off, then mild soap solution in the evening.
Poinsettia is far less poisonous than its reputation. Clemson’s extension notes it is not considered toxic; eating leaves may cause a stomach ache, vomiting or diarrhoea, and the milky sap can cause a mild skin rash. Wash sap off skin with soap and water and flush eyes with water. People with latex allergy should wear gloves. Still keep it away from toddlers and pets who chew, and seek advice if a child has eaten some and is unwell. For plants that are genuinely dangerous, see our poisonous plants guide.
Should you grow poinsettia?
| Situation | Verdict | Why |
|---|---|---|
| Karachi or Lahore house with a dark garden corner | Plant in ground | Colours naturally every winter |
| Lit city flat, willing to do the box routine | Maybe | Works if you never miss nights |
| Want a one-season table plant | Plant | Buy in December, enjoy, compost or keep |
| Hill house without a heated room | Skip outdoors | Frost kills it |
Browse more winter colour in Phool aur Paudhe.
Poinsettia questions people ask
How do I make my poinsettia turn red again?
Give it 14 hours of complete darkness every night and full sun by day for 8 to 10 weeks from early October. Any light at night interrupts the process.
How do you grow poinsettia from cuttings?
Take 10 cm soft tips between April and June, stop the sap, plant in damp sandy mix under a humid cover, and keep in bright shade. Roots form in about a month.
When should I cut back my poinsettia?
In March, after the colour fades. Pinch new growth in early summer, but stop pinching by September or you lose this winter’s colour.
Can poinsettia grow outdoors in Pakistan?
Yes, in Karachi and much of Punjab and Sindh it grows into a large shrub. Shelter it from frost in Lahore and Islamabad, and keep it indoors in the hills.
Why is my poinsettia losing leaves?
Cold draughts, wet roots or a sudden move to a dim room. Check drainage, keep it away from cold doors, and give it bright light.
What is the best fertilizer for poinsettia?
A balanced fertiliser at label strength every 3 to 4 weeks from spring to October, plus compost. Feeding does not make it red; darkness does.
How do I care for poinsettia in winter?
Bright sun by day, water only when the top dries, no feeding once coloured, and protection on frost nights.
Is poinsettia poisonous to children and pets?
It is mildly irritating rather than seriously poisonous. Eating leaves can upset the stomach and the sap can irritate skin, so keep it out of reach anyway.
How long do poinsettia bracts stay red?
Often two to three months in cool weather, from December into February or March, longer in a bright, cool spot.