What temperature is too cold for poinsettias?

Poinsettias begin to suffer damage when temperatures drop below 50 degrees Fahrenheit (10 degrees Celsius).

Understanding Poinsettia Temperature Sensitivity

Poinsettias are tropical plants native to Mexico, making them highly sensitive to cold temperatures. Exposure to temperatures below 50°F (10°C) will cause noticeable damage to the plant, impacting its health and appearance. Even more critically, freezing temperatures (32°F / 0°C or below) are lethal and will quickly kill the poinsettia. Understanding these thresholds is vital for proper care and ensuring your plant thrives throughout the holiday season and beyond.

Ideal Temperature Range for Poinsettias

While below 50°F is too cold, there's an optimal range where poinsettias flourish. They prefer a consistent environment with moderate temperatures.

• Daytime: Ideally, poinsettias thrive in temperatures between 65-70°F (18-21°C).
• Nighttime: For robust health and vibrant bracts (the colored leaves), nighttime temperatures should ideally be slightly cooler, around 60-65°F (15-18°C).

Maintaining stable temperatures, avoiding sudden fluctuations, is key to their well-being.

Signs of Cold Damage

When poinsettias are exposed to overly cold conditions, they exhibit several warning signs:

• Leaf and Bract Drop: One of the most common indicators is the dropping of leaves and colored bracts.
• Wilting: The plant may appear droopy, even if adequately watered.
• Yellowing or Browning: Leaves may turn yellow or brown, especially at the edges.
• Stunted Growth: Overall growth can slow or stop.
• Limp Stems: In severe cases, stems might become soft and mushy.

Protecting Your Poinsettias from Cold

Taking proactive steps can help you safeguard your poinsettia from cold damage:

1. Strategic Placement: Keep your poinsettia away from drafty windows, exterior doors, and cold air vents. Place them in a brightly lit room that maintains a consistent warm temperature.
2. Avoid Cold Surfaces: Do not place the plant directly on cold surfaces like stone windowsills or unheated floors. Use a saucer or trivet for insulation.
3. Proper Transport: When bringing a poinsettia home from a store, especially in cold weather, ensure it is well-wrapped to protect it from cold shock during transit. This might involve using a sleeve, bag, or even placing it in a box.
4. Watering Practices: While consistent moisture is important, avoid overwatering, particularly if your home is cooler, as soggy soil combined with low temperatures can lead to root rot and further stress the plant.

Poinsettia Temperature Guide

The table below summarizes the effect of various temperatures on poinsettias, highlighting why careful temperature management is crucial for these beautiful plants.

For more detailed information on poinsettia care, including watering and light requirements, you can refer to reliable horticultural resources, such as those provided by university extension programs.