Will A Plastic Greenhouse Keep My Plants From Freezing?

If you’ve ever wondered if a plastic greenhouse is the solution to preventing your precious plants from succumbing to the biting cold of winter, then you’re in luck. In this article, we’ll explore the effectiveness of plastic greenhouses in shielding your plants from freezing temperatures. Whether you’re an avid gardener or a novice plant parent, you’ll get all the information you need to make an informed decision and keep your plants cozy throughout the winter season. So let’s get started on this leafy adventure and discover if a plastic greenhouse is the answer to your frosty woes!

Why Use a Plastic Greenhouse?

Effective Insulation

When it comes to protecting your plants from freezing temperatures, a plastic greenhouse can be an excellent solution. The plastic material used in these structures is known for its effective insulation properties. The plastic minimizes heat loss and creates a warm environment inside the greenhouse, shielding your plants from the harsh cold weather outside. This effective insulation can help prevent frost damage and keep your plants healthy even during colder months.

Affordable Option

Another advantage of using a plastic greenhouse is its affordability. Compared to other types of greenhouses made from materials like glass or fiberglass, plastic greenhouses are generally more cost-effective. The plastic material used is relatively inexpensive, making it a great choice for budget-conscious gardeners or hobbyists. Despite its lower price point, plastic greenhouses still offer excellent insulation and protection, making them a practical choice for plant enthusiasts.

Easy to Install

Plastic greenhouses are also renowned for their ease of installation. Unlike some other types of greenhouses that may require professional assistance or complex assembly processes, plastic greenhouses can be relatively straightforward to set up. Many plastic greenhouse kits come with detailed instructions, and with a little effort, you can easily complete the installation on your own. This convenience makes plastic greenhouses a popular choice for gardeners of all skill levels, from beginners to experienced plant enthusiasts.

Factors to Consider

Temperature Extremes

Before purchasing a plastic greenhouse, it’s important to consider the temperature extremes in your area. Plastic greenhouses provide effective insulation, but they may not be suitable for regions with extreme temperature fluctuations or prolonged periods of cold weather. If your area experiences severe cold or hot temperatures, you may need to invest in additional heating or cooling systems to maintain optimal conditions inside the greenhouse.

Plant Type

Different plants have different temperature requirements. Some plants thrive in cooler temperatures, while others require warmer conditions. Before choosing a plastic greenhouse, consider the types of plants you want to grow and their specific temperature needs. Certain plants may require additional heating or cooling measures, depending on their preferred climate. Make sure to choose a plastic greenhouse that can accommodate the temperature requirements of your desired plant species.

Size of the Greenhouse

The size of the greenhouse is another important factor to consider. Determine the amount of space you need based on the number and size of the plants you plan to grow. If you have limited space or only a few plants, a smaller greenhouse may be sufficient. However, if you have a larger garden or want to cultivate a wide variety of plants, a larger plastic greenhouse will be necessary. Ensure that the greenhouse you choose provides enough space and ventilation for your plants to grow comfortably.

Choosing the Right Plastic Greenhouse


When selecting a plastic greenhouse, it’s crucial to consider its durability. Look for a greenhouse made from high-quality plastic that can withstand various weather conditions and resist damage from sunlight exposure. UV-resistant plastic is an excellent choice, as it can prevent yellowing or degradation of the material over time. Additionally, check for features like sturdy frames and reliable fastening systems to ensure the longevity of your greenhouse.

Size and Capacity

The size of the greenhouse should align with your gardening needs. Consider how many plants you want to grow and the space required for each plant to thrive. Additionally, think about future expansion plans or the possibility of adding extra shelving or workspace. It’s better to choose a slightly larger greenhouse than you initially need, as it provides room for growth and flexibility in case your plant collection expands.

UV Protection

UV protection is a crucial factor to consider when choosing a plastic greenhouse. Excessive exposure to UV rays can harm your plants and compromise their health. Look for plastic greenhouses that offer UV protection to shield your plants from harmful radiation. This feature helps maintain optimal growing conditions and ensures that your plants can flourish without the negative effects of excessive sunlight exposure.

Proper Ventilation

Importance of Ventilation

Proper ventilation is essential for the health and well-being of plants inside a plastic greenhouse. Ventilation helps regulate temperature, humidity, and air circulation, preventing issues like mold, fungal diseases, or stagnant air. Without adequate ventilation, the greenhouse can become too hot or too humid, leading to plant stress and reduced productivity. It’s vital to ensure that your plastic greenhouse has proper ventilation mechanisms in place.

Types of Ventilation

There are various types of ventilation systems you can integrate into your plastic greenhouse. Some common options include roof vents, sidewall vents, and exhaust fans. Roof vents allow warm air to escape and promote air circulation, preventing excessive heat buildup. Sidewall vents can be opened to allow fresh air in and stale air out. Exhaust fans are effective for removing hot air during the warmer months. Consider the climate in your area and choose a ventilation system that suits your specific needs.

Maintaining Proper Airflow

Maintaining proper airflow within the greenhouse is crucial. Dead air pockets can promote the growth of mold, which can be detrimental to your plants. To ensure good airflow, avoid overcrowding your plants and leaving enough space between them. Regularly clean and remove any debris that may hinder air movement. Additionally, consider using circulation fans to promote air circulation throughout the greenhouse, especially in corners or areas with limited airflow.

Temperature Control

Importance of Temperature Control

Temperature control is paramount for the successful cultivation of plants in a plastic greenhouse. Different plants thrive in different temperature ranges, and maintaining optimal conditions can greatly enhance their growth and yield. With proper temperature control, you can extend the growing season, protect plants from frost, and create a conducive environment for healthy growth.

Heating Options

Plastic greenhouses can provide a suitable environment for plants, even during colder months, by incorporating heating options. Common heating methods include electric heaters, propane heaters, or radiant heaters. Electric heaters are often the most convenient option as they require minimal maintenance and provide consistent heat. Propane heaters are portable and offer a fuel-efficient heating solution. Radiant heaters provide uniform heat distribution and are suitable for larger greenhouses.

Thermostat and Climate Control

To maintain precise temperature control, consider installing a thermostat or climate control system in your plastic greenhouse. These devices allow you to monitor and regulate the temperature automatically, ensuring that your plants are kept within their desired temperature range. A thermostat can activate the heating system when the temperature drops below a certain set point and turn it off once the desired temperature is reached. This automated control eliminates the hassle of manually adjusting the heating system and provides a stable environment for your plants.

Additional Protection from Freezing

Insulation and Frost Covers

In colder climates, additional protection may be necessary to safeguard your plants from freezing temperatures. Insulation materials, such as bubble wrap or straw, can be used to cover the plants during particularly cold nights, creating an additional layer of warmth. Frost covers, made from breathable materials, can also be used to shield plants from frost damage without restricting air circulation. These protective measures can help prevent freezing and protect your plants during colder periods.

Heat Domes and Heat Lamps

Heat domes and heat lamps are effective tools for providing localized heat within a plastic greenhouse. Heat domes are transparent covers that trap heat around individual plants, creating a small microclimate. Heat lamps emit focused heat and can be directed toward sensitive or fragile plants. These additional heat sources can help protect plants that are more susceptible to cold temperatures and ensure their survival during freezing conditions.

Avoiding Condensation

Condensation can be a common issue in plastic greenhouses, especially in areas with high humidity or temperature fluctuations. Excessive condensation can negatively impact plant health by promoting the growth of mold and fungal diseases. To minimize condensation, ensure proper ventilation and air circulation within the greenhouse. Additionally, consider using dehumidifiers or fans to reduce moisture levels and regulate humidity. Regularly wipe off any condensation that forms on the walls or surfaces to prevent water droplets from falling on your plants.

Maintenance and Care

Cleaning and Sanitizing

Regular cleaning and sanitizing are essential for maintaining a healthy plastic greenhouse. Remove any fallen leaves, debris, or dead plant materials to prevent the buildup of pests or diseases. Clean all surfaces, including the walls and flooring, to eliminate any potential sources of contamination. Sanitize tools and equipment used within the greenhouse to prevent the spread of pathogens. Regular cleaning and sanitizing practices help create a clean and pest-free environment for your plants.

Monitoring for Pests and Diseases

Pests and diseases can pose a significant threat to the well-being of your plants inside a plastic greenhouse. Regularly inspect your plants for any signs of pests, such as aphids or spider mites, and promptly take appropriate measures to control their population. Monitor for any symptoms of diseases, such as wilting or abnormal growth, and apply appropriate treatments if necessary. Maintaining a vigilant watch for pests and diseases allows for early intervention and prevents potential damage to your plants.

Regular Inspections

Performing regular inspections of your plastic greenhouse is crucial for identifying any maintenance or repair needs. Check for any cracks or tears in the plastic material and repair them promptly to maintain the greenhouse’s insulation properties. Inspect the frames, hinges, and fastening systems for any signs of wear or damage, replacing or repairing as needed. Regular inspections ensure that your plastic greenhouse remains in good condition, providing a long-lasting and effective environment for your plants.

Advantages and Disadvantages of Plastic Greenhouses


Plastic greenhouses offer several advantages that make them a popular choice among garden enthusiasts. They provide effective insulation, keeping plants protected from freezing temperatures and frost damage. Plastic greenhouses are also considerably more affordable than other types of greenhouses, making them a practical option for both beginners and experienced gardeners. Additionally, they are easy to install, allowing you to quickly set up your greenhouse and start cultivating your plants without much hassle.


While plastic greenhouses have many benefits, they also come with a few disadvantages. Over time, the plastic material can degrade or discolor due to prolonged exposure to sunlight. This may require periodic replacement of the plastic covering to maintain its effectiveness. Plastic greenhouses may also be less durable than other types, such as glass or fiberglass, and may not withstand extreme weather conditions as well. Additionally, some gardeners prefer the aesthetic appeal of glass or more substantial structures over plastic.

Alternative Options for Cold Protection

Cloches and Row Covers

Cloches and row covers are smaller-scale options for protecting plants from frost and freezing temperatures. Cloches are individual covers placed directly over individual plants, providing a mini-greenhouse effect. Row covers, on the other hand, are draped over rows of plants to create a protective barrier. These options are ideal for gardeners with limited space or those who want to protect specific plants without investing in a full-sized greenhouse.

Portable Greenhouses

Portable greenhouses offer flexibility and convenience for cold protection. These lightweight structures are easy to assemble and disassemble, making them ideal for gardeners who need temporary cold protection during specific periods. Portable greenhouses can be moved around the garden, allowing for optimal placement based on sunlight and temperature requirements.

Cold Frames

Cold frames are an alternative option that provides excellent protection against cold temperatures. These low, enclosed structures have a transparent cover, typically made from plastic or glass, and are placed directly on the ground. Cold frames capture and retain heat from the sun, creating a warm microclimate for plants. They are versatile and can be used to start seedlings early in the season or protect delicate plants during winter.


A plastic greenhouse can be a valuable asset for gardeners looking to protect their plants from freezing temperatures and extend the growing season. With effective insulation, affordability, and ease of installation, plastic greenhouses offer many advantages. When choosing a plastic greenhouse, consider factors such as temperature extremes, plant type, and greenhouse size. Proper ventilation, temperature control, and additional protection measures like insulation and frost covers are also essential. Regular maintenance, cleaning, and monitoring for pests and diseases are necessary to ensure optimal conditions for plant growth within the greenhouse. While plastic greenhouses have their advantages and disadvantages, they provide a practical and accessible option for avid gardeners. If a full-sized greenhouse is not feasible, alternative options like cloches, row covers, portable greenhouses, or cold frames can also provide effective cold protection for your plants. With the right approach and proper care, a plastic greenhouse can help you create a thriving garden even in the coldest of climates.

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About the Author: Jake Scott