How Warm Will A Greenhouse Stay In Winter?

Imagine the joy of having a thriving greenhouse in your backyard, providing you with fresh produce all year round. But before you embark on this green-fingered venture, one question undoubtedly lingers in your mind: just how warm will a greenhouse stay during the chilly winter months? In this article, we will uncover the secrets behind maintaining a cozy and regulated environment for your plants, ensuring their health and productivity throughout the colder seasons. So, join us as we explore the fascinating world of greenhouse temperature control and discover the ins and outs of winter greenhouse management.

Factors affecting the temperature inside a greenhouse during winter

When it comes to maintaining the temperature inside a greenhouse during the winter months, there are several factors that come into play. Understanding these factors can help you create an optimal environment for your plants and ensure their successful growth. Let’s explore each of these factors in more detail.

Location and climate

The geographical location of your greenhouse plays a significant role in determining the temperature inside during winter. Different regions have varying winter temperatures, and understanding the average winter temperatures in your area is crucial in planning for your greenhouse. If you live in a colder climate, you may need to invest in additional heating mechanisms to maintain the desired temperature.

The microclimate of your greenhouse also plays a part. Factors such as the amount of sun exposure, the presence of nearby structures or trees that provide shade, and the wind patterns in your area can all influence the temperature inside the greenhouse. Consider these factors when choosing the location for your greenhouse.

Greenhouse design and materials

The design and materials used in your greenhouse can significantly impact its ability to retain heat during the winter. There are various types of greenhouse structures available, such as hoop houses, gable-roofed greenhouses, and geodesic domes. Each design has its advantages and disadvantages when it comes to heat retention.

The choice of glazing materials is another important consideration. Glass, polycarbonate, and polyethylene film are common options. Glass provides excellent insulation but can be expensive. Polycarbonate offers good insulation while also being more durable and affordable. Polyethylene film is an inexpensive option but may require regular replacement.

The size and orientation of your greenhouse also matter. A larger greenhouse generally retains heat better due to the increased thermal mass. Additionally, the orientation of the greenhouse in relation to the sun can optimize solar heat gain.

Structural insulation, such as adding double layers of plastic film or insulating the walls and roof, can further improve heat retention in your greenhouse.


Insulating your greenhouse is crucial in preventing heat loss during winter. Adequate insulation helps maintain a consistent temperature and reduces the energy required for heating.

Start by insulating the walls and roof of your greenhouse. This can be done using materials like polystyrene boards, fiberglass, or reflective insulation. Ensure there are no gaps or drafts that can let cold air in.

Consider adding double glazed windows or panels to enhance insulation. The trapped air between the layers acts as an insulating barrier. Weatherstripping around doors and windows can also prevent air leaks.

Another cost-effective solution is using thermal curtains or bubble wrap. These can be hung inside the greenhouse to create an additional layer of insulation during the colder months.

Heat sources

Choosing the right heat sources for your greenhouse is essential in maintaining a suitable temperature. There are several options to consider, including electric heaters, gas heaters, biomass heaters, solar heating, composting, and radiant heaters.

Electric and gas heaters are commonly used due to their effectiveness in providing consistent heat. They can be controlled easily and are available in various sizes to suit different greenhouse layouts. Biomass heaters, such as wood-burning stoves or pellet burners, are a sustainable option but require careful monitoring and maintenance.

Utilizing solar heating can significantly reduce energy costs. This can be achieved through passive solar design, where the greenhouse is strategically positioned to maximize sunlight exposure, or by incorporating solar panels to generate renewable energy for heating.

Composting is another natural heat source that can be utilized in a greenhouse. The decomposition process generates heat, helping to warm the surrounding air. A compost pile or a dedicated composting system can be integrated into your greenhouse design.

Radiant heaters provide targeted heat to specific areas or plants. These heaters emit infrared radiation, which warms objects directly without heating the surrounding air, making them an efficient option.


Proper ventilation is crucial in regulating the temperature and humidity inside a greenhouse. It helps remove excess moisture, prevents condensation, and allows fresh air circulation.

Natural ventilation can be achieved through adjustable vents, windows, or roof vents. The placement and size of these openings should be carefully considered to maximize air exchange without compromising heat retention.

Forced ventilation systems, such as fans or blowers, can be used to supplement natural ventilation when necessary. These systems help maintain a consistent airflow, especially on warm, sunny days when excess heat needs to be removed.

Installing dampers and louvers can aid in controlling airflow, allowing you to fine-tune ventilation based on your greenhouse’s specific needs.

Thermal mass

Using thermal mass materials in your greenhouse can help stabilize temperature fluctuations. Thermal mass refers to materials that can absorb and store heat, releasing it slowly over time. Some common thermal mass materials include water barrels or containers, stone or concrete flooring, and brick or masonry walls.

Water barrels or containers placed strategically throughout the greenhouse can absorb and release heat, helping maintain a stable temperature. Stone or concrete flooring acts as a heat sink, absorbing heat during the day and releasing it at night. Similarly, brick or masonry walls provide thermal mass, helping to regulate temperature variations.

Using heat-absorbing materials, such as dark-colored surfaces or heat-retaining stones, can also contribute to stabilizing the temperature inside your greenhouse.

Plants and their heat requirements

Different plants have varying heat requirements, and understanding these needs is crucial in maintaining an optimal greenhouse temperature during winter.

Choosing cold-tolerant plants that can withstand lower temperatures is a great strategy. Research which plant species are best suited for your climate and adjust your selection accordingly.

Grouping heat-loving plants together can also help maintain higher temperatures in a specific area or zone within your greenhouse. This way, you can create microenvironments that cater to the specific needs of these plants.

Using plant insulation techniques, such as row covers or cloches, can provide an extra layer of protection to your plants. These coverings help trap heat around individual plants, preventing excessive heat loss.

Adjusting your growing techniques, such as spacing your plants closer together to create a microclimate, can also help maintain higher temperatures.

Covering material

The choice of greenhouse covering material can significantly impact the temperature inside. Different materials offer varying levels of insulation and light transmission.

When choosing the right greenhouse covering, consider factors such as insulation value, durability, light transmission, and cost. Insulated greenhouse panels, such as twin-wall polycarbonate or acrylic sheets, provide excellent insulation and durability. They are also UV resistant, reducing the risk of damage over time.

Polycarbonate sheets are a popular choice due to their durability, light transmission, and insulation properties. They are available in various thicknesses, allowing you to choose the optimal option for your specific climate.

Double-layered polyethylene film is a cost-effective option with decent insulation properties. However, it requires regular replacement to maintain its effectiveness.


Regular maintenance of your greenhouse is essential in ensuring its efficiency and functionality. Inspect your greenhouse regularly for any air leaks, damaged glazing, or insulation that may need repair or replacement.

Clean the glazing regularly to maximize light transmission. Clear glazing allows for better solar heat gain during the day, helping to warm the greenhouse.

Periodically check and maintain your heating systems to ensure they are operating efficiently. Clean or replace filters, inspect gas lines for leaks, and schedule professional maintenance if necessary.

Size of the greenhouse

The size of your greenhouse can affect its ability to retain heat. In general, larger greenhouses have increased thermal mass, allowing them to retain heat better.

Consider the optimal size for efficient heating based on your specific requirements. A greenhouse that is too small may result in temperature fluctuations, while one that is too large might require excessive heating resources to maintain the desired temperature. Balancing size and heating needs is crucial in creating a sustainable and energy-efficient greenhouse.

Controlling temperature fluctuations is vital in maintaining an optimal environment for your plants. Monitor the temperature inside your greenhouse regularly and make necessary adjustments to your heating and ventilation systems as needed.

By considering these factors affecting the temperature inside a greenhouse during winter, you can create a suitable environment for your plants’ growth and ensure their well-being throughout the colder months. With careful planning and implementation, you can enjoy a thriving greenhouse that provides the ideal conditions for your plants to flourish.

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About the Author: Jake Scott