The Poinsettia ('Euphorbia pulcherrima'), often nicknamed the "Christmas Star," is the world's best-selling plant during the holiday season. This small shrub, native to Mexico, is celebrated for its spectacular colourful bracts (often mistaken for flowers) that can remain vibrant from November to March, provided cold drafts are avoided. Long limited to the classic red, the range of colours and shapes has widely expanded, offering a decorative choice for all styles.
Varieties: Beyond the Traditional Red
What we call the "flowers" of the Poinsettia are actually bracts, modified leaves that surround the tiny yellow flowers (cyathia) located in the centre. Growers have developed thousands of cultivars offering a fascinating palette of colours and shapes:
Most Popular Colours and Patterns
- Red (Classic): The most common colour, accounting for about 75% of sales. Modern varieties have deeper reds and better bract retention (examples: 'Prestige Red', 'Titan').
- White and Cream: Soft and sophisticated tones, perfect for modern winter decor (example: 'Alaska').
- Pink and Salmon: A range from bright pink to pale salmon, very popular in recent years (example: 'Da Vinci', 'Enduring Pink').
- Marbled, Speckled, and Variegated: Bracts display mixtures of two colours. The cultivar 'Ice Punch' is very popular, with red bracts speckled with white or cream at the center, giving a "frosted" effect. 'Jingle Bells' or 'Sonora White Glitter' varieties are also examples of bicolour bracts.
Distinctive Bract Shapes
- Oak Leaf: The bracts are slightly lobed, like oak leaves, giving a less traditional look (example: 'Cortez Burgundy').
- Wavy or Curled: The bracts curl downwards, giving a rose or double flower effect (the 'Winter Rose' series). These varieties are generally smaller and more compact.
The Princettia: A Revolution in Form
The Princettia is a registered brand name for a series of specially selected Poinsettia cultivars. Their particularity is to grow naturally more compact and bushy, with smaller and more abundant leaves and bracts. They are ideal for small spaces and offer a very dense habit. They are most often available in shades of bright pink and fuchsia.
Use and Benefits: Festive Decor and Versatility
The Poinsettia is a master choice for several reasons:
- Winter Colour: It offers vibrant, long-lasting colour when most other houseplants are dormant.
- Draft Detector: The Poinsettia is the perfect indicator of cold drafts. If it starts to drop its leaves quickly, it means it has been exposed to cold and that your window or door is leaking.
- Wide Availability: Easy to find at all florists and garden centres during the months of November and December.
Care: Avoid Stress and Cold
The key to keeping a Poinsettia looking beautiful is to avoid temperature extremes and excess water.
Light and Warmth: No Cold, Plenty of Light
The Poinsettia needs the brightest possible light, ideally near a South or West-facing window. However, it should never touch the glass, as this could burn it. Its ideal temperature is between 18 °C and 21 °C (65 °F and 70 °F).
Golden Rule: The Poinsettia does not tolerate cold. If the temperature drops below 12 °C (54 °F), it will drop its leaves and bracts. This is often the cause of the plant's premature death after purchase (exposure to cold during transport).
Watering: Never Soggy, Never Dry
Unlike succulents like Kalanchoe, the Poinsettia is not drought tolerant. Water when the top inch (2 or 3 cm) of the soil, checked with your finger, is dry.
Aesthetic Drainage Tip: Poinsettias are often sold in nursery pots (plastic) wrapped in foil or a decorative sleeve. Remove the decorative sleeve or foil before watering to ensure drainage. You can place the nursery pot directly into a decorative cache-pot that matches your decor.
For optimal watering:
- Water thoroughly until water drains through the drainage holes.
- Empty the saucer after 15 minutes. Roots sitting in standing water will rot very quickly.
- Misting is Not Necessary.
Fertilization and Pruning After the Holidays
Repotting After Purchase: It is not necessary to repot your Poinsettia immediately after purchase. It is in bloom, and this stress could cause the bracts and leaves to drop. Wait until the end of the blooming period (March or April) to repot if you decide to keep it.
Fertilization: Do not fertilize the plant during its blooming period (November to March). Start applying a balanced indoor fertilizer once the active growth period resumes, in the spring (May-June).
Post-Bloom Pruning: Once the bracts have faded (March or April), prune the plant back severely to encourage it to form a compact bush. Cut the stems to about 15 to 20 cm (6 to 8 inches) in height. This is essential if you want to keep it and make it rebloom.
Reblooming: The Short-Day Secret
To get coloured bracts the following year, you need to simulate the Mexican winter. The Poinsettia is a short-day plant, meaning it requires a period of total, uninterrupted darkness to transform its green leaves into coloured bracts.
The Process (Mid-September to Early November):
- Total Darkness: Every day, expose the plant to 14 hours of total, consecutive darkness. The slightest light source (street lamp, television, kitchen light) will ruin the process. Place the plant in a dark closet or cover it with an opaque box from 5 PM to 7 AM.
- Bright Light: During the remaining 10 hours of the day, give it very bright light.
- Repeat this cycle without fail for 6 to 8 weeks. Once the bracts start to colour up (around late November), you can stop the darkness treatment.
Common Problems and Solutions
- Rapid Drop of Green Leaves: Almost always caused by thermal shock or a cold draft. Check if the plant is near a poorly insulated window or door. Protect it from frosty windows and heating vents.
- Soft Leaves or Yellowing: A sign of overwatering. Let the soil dry out more between waterings and ensure water never sits in the saucer.
- Browning Flower Peduncles: The natural end of blooming. This is the time to prune the plant if you want to keep it.
- Failure to Rebloom/Bract Discoloration: The total darkness treatment was not respected. The plant received artificial light during the night.
Important Warning
Safety: Contrary to popular belief, the Poinsettia is mildly toxic and does not pose a severe, life-threatening danger if ingested (especially to humans). However, its sap (a white latex) can cause slight skin irritation in some people and mild digestive upset in pets. Handle with gloves if you have sensitive skin. Place the plant out of reach of young children and pets as a precaution.
