Native to Mexico, poinsettias are in the Euphorbia family and are a popular holiday plant because of their colorful bracts (leaves). There is also a species that is used as a cut flower.
They are most commonly used for decorating during the winter holidays but are also attractive as green plants throughout the year.
Poinsettias change color in response to shorter winter days. Poinsettia flowers are made up of the bracts, which look like petals, and the tiny yellow flowers in the center, called cyathia. The colorful bracts attract insects to the flowers and will drop after pollination.
Poinsettias are a popular holiday plant known for their bright, colorful bracts. While they make festive decorations during the winter months, keeping them alive and thriving can seem daunting. One of the most important factors in poinsettia care is proper sunlight. Read on to learn exactly how much sunlight poinsettias need to stay healthy and produce colorful blooms.
Light Requirements for Poinsettias
Poinsettias are native to southern Mexico and Central America where they grow as perennial flowering shrubs. To bloom and produce their signature red, pink, or white bracts, poinsettias require specific photoperiods or light exposures.
Poinsettias are short-day plants, meaning they bloom in response to decreasing day lengths. As daylight hours shorten in the fall, poinsettias start to set buds which develop into the colorful bracts. In their native climates, poinsettias experience 10-12 hours of daylight during summer. This drops down to 12 hours or less of daylight around October to trigger blooming.
When growing poinsettias as houseplants, it’s important to replicate their natural light conditions. Here are the recommended sunlight requirements:
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6-8 hours of bright, indirect light per day – This allows poinsettias to bloom properly without fading or scorching the bracts. East, south or west-facing windows are ideal.
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Avoid direct sunlight – Direct sun can burn the bracts causing them to fade and shrivel prematurely. Filtered sun from a sheer curtain works well.
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No fewer than 8 hours of darkness – Long nights are needed to form buds and colorful bracts. Keep poinsettias in complete darkness from 5pm to 8am daily.
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Avoid drafts or excessive heat – Cold drafts or excessive heat from heating vents can dry out the bracts and cause leaf drop.
Optimizing Sunlight Indoors
The right balance of light and darkness can be challenging to provide indoors. Here are some tips for giving your poinsettia the sunlight it needs:
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Place your poinsettia near an east or west-facing window. These locations provide gentle morning or afternoon sun without intense midday rays.
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Use sheer curtains to softly filter direct sunlight streaming in from south-facing windows. Close heavier drapes or blinds at night.
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Turn plants weekly so all sides receive equal light exposure. This prevents lopsided growth toward the light source.
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Provide supplemental lighting with grow lights if your home lacks sufficient natural light. LED grow light bulbs easily screw into regular fixtures
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Keep poinsettias out of low light areas like hallways or far from windows. Without enough light, blooms will fail to form properly.
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Avoid placing poinsettias near heat sources like appliances, fireplaces or heating vents which can dry and damage the colorful bracts.
Signs of Insufficient Light
It’s easy to tell if your poinsettia is getting too much or not enough sunlight. Here’s what to look for:
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Loss of color or greening of bracts – This indicates the plant isn’t getting the requisite hours of uninterrupted darkness needed to bloom.
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Leggy growth – When reaching or stretching for light, poinsettia stems become long and spindly with sparse foliage.
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Drooping or wilting – Insufficient light leads to weak, underdeveloped stems unable to support the weight of leaves and bracts.
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Failure to bloom – Without around 6 hours of adequate sunlight daily, poinsettia buds won’t form at all.
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Bract scorching – Too much direct sun burns or bleaches the colorful bracts to a faded brownish red.
Moving Plants Outside
Once blooming finishes in late winter or early spring, you can move your poinsettia outdoors if your climate is suitable. Poinsettias make excellent landscape plants in USDA Hardiness Zones 9-11.
When transitioning a poinsettia outside, gradually introduce it to more intense sunlight:
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Start by placing it in dappled or partial shade protected from harsh midday sun.
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Slowly increase light exposure over 7-10 days to acclimate the plant.
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Only set poinsettias in full sun once adapted to outdoor conditions.
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Provide shade in zones 8 and warmer if planting in full sun.
With the right balance of sunlight tailored to their photoperiodic needs, poinsettias can thrive as cheerful seasonal bloomers or attractive garden shrubs. Pay close attention to your plant’s light exposure and make adjustments as needed to keep those colorful bracts vibrant. With proper care, you can enjoy poinsettias long after the holiday season ends!
Frequently Asked Questions
How much sunlight does a poinsettia need per day?
Poinsettias require around 6-8 hours of bright, indirect sunlight daily to bloom properly. This can be provided via an east, west or lightly filtered south-facing window. Complete darkness for at least 8 hours is also needed.
Where should I place my poinsettia?
The best spots are near east, west or lightly shaded south-facing windows. This provides gentle morning or afternoon sun. Avoid direct southern exposure which can scorch the bracts.
Do poinsettias need direct sun?
No, poinsettias should never be placed in direct sunlight. Their bracts will fade and burn if exposed to intense, direct rays. Filtered or indirect sunlight works best.
What causes poinsettias to turn green?
Insufficient darkness is usually the culprit when poinsettia bracts turn from red to green. The plants require long, uninterrupted nights to form colorful blooms. Make sure poinsettias get 14 hours of total darkness daily.
How do I know if my poinsettia has too much sun?
Signs of excess sunlight include faded, bleached or dried bracts, yellowed foliage and leaf scorching or burn. Bracts may turn green from lack of darkness. Moving plants away from direct sun or intense heat resolves these issues.
When should I move my poinsettia outside?
Wait until any risk of frost has passed and nighttime temperatures stay above 55°F before placing poinsettias outdoors. Gradually introduce the plants to full sun over 7-10 days. Provide afternoon shade in zones 8 and warmer.
Poinsettias come in many colors
You can find poinsettias around the holidays to fit into almost any decorative scheme. They range from creamy white to pink to the traditional bright red. Some varieties have bracts with patterns in red and white, pink and white, or green and white and even bright orange.
Flower forms vary as well with some looking similar to a rose. You will also find unusually colored poinsettias such as blue or purple in garden centers. These are cream-colored varieties that are spray painted. They are sometimes sprinkled with glitter.
- Indoor light: Put in a south, east or west window where the plant will receive bright daylight.
- Outdoor light: Part sun, 4 to 6 hours daily.
- Temperature:
- Indoor temperatures of 65 to 70 degrees F are ideal.
- Avoid placing poinsettias where the temperature fluctuates or may be drying, such as near cold drafts, heat ducts, fireplaces, fans, space heaters, etc.
- Poinsettias will suffer damage if they are exposed to temperatures below 50 degrees F.
- Freezing temperatures will kill poinsettias.
- Keep soil moist.
- Water plant when the soil surface feels dry to a light touch, or the pot feels lightweight when lifted. Never allow poinsettias to get so dry that they wilt.
- Remove from decorative foil or outer pot before watering.
- Make sure your plant is in a pot that drains freely.
- Set the plant in a sink and water thoroughly, allowing the plant to drain completely.
- Never allow poinsettia pots to sit in excess water. Constant wetness will rot plant roots.
- You do not need to fertilize your poinsettia during the holidays.
- Start fertilizing your plant when you see new growth (new green leaves, stems, bracts).
- Fertilize with an all-purpose household plant fertilizer.
- Mix with water it at half the recommended strength.
- Feed your poinsettia every 3-4 weeks to keep the plant healthy and provide the necessary nutrients for new growth.
In late spring or early summer, transplant your poinsettia into a larger container (about 2 to 4 inches bigger than the original pot) or a part-sun garden bed.
- In pots, use a soil mix with a good amount of organic matter such as peat moss. Make sure your new pot has good drainage.
- In the garden, plant into a garden bed with well-drained soil that gets 4 to 5 hours of sun per day. Mix in organic matter such as peat moss or compost into the soil. This will help maintain soil moisture and create a good growing environment for the roots.
- Water your poinsettia thoroughly after transplanting.