March 19


Preparing Your Greenhouse for Winter: 6 Essential Steps to Keep Your Plants Healthy During the Cold Weather

How to winterize a greenhouse – 6 steps to get ready for the cold weather

As autumn approaches, it’s important for greenhouse owners to start thinking about winterizing their structures. Greenhouses provide a controlled environment for plants to thrive throughout the year, but their policy of protecting plants from the elements doesn’t apply to the colder months.

Knowing how to winterize your greenhouse is essential for ensuring the survival of your plants and maximizing their growth. Insulation, proper lighting, and heating units are just some of the tools you’ll need to prepare your greenhouse for the winter. But before you begin the process, it’s important to thoroughly clean and store any potting or gardening tools that you may have in your greenhouse to avoid damage from frost or cold temperatures.

One of the most important steps in winterizing your greenhouse is to insulate the structure. Greenhouses are often made with glass or plastic walls, which don’t provide much insulation. Therefore, it’s essential to wrap the outside of the greenhouse with bubble wrap or an insulation material to help retain heat and protect your plants from the cold weather.

In terms of heating, a heated greenhouse can extend the growing season well into the winter months. Griffin explains that if your greenhouse doesn’t have a heating system, you can use a cable heater or heated water units placed throughout the greenhouse to keep the temperatures above freezing. However, make sure to follow safety guidelines and never leave these heating sources unattended.

Water storage is also crucial for winterizing your greenhouse. As the weather gets colder, the faucet outside your greenhouse may freeze, making it difficult to water your plants. One solution is to install a heated faucet or heat tape to prevent freezing. Another option is to have a water storage container inside your greenhouse that you can fill up and use throughout the winter.

Covering the roots of your plants is another important step in winterizing your greenhouse. Perennials and other plants that you want to overwinter will need extra protection from the cold. Using a thick layer of mulch or straw around the base of the plants can help insulate the roots and provide them with the warmth they need to survive until the next growing season.

How to winterize a greenhouse

As the weather gets colder, it’s important to take steps to protect your greenhouse and ensure that your plants survive the winter months. Winterizing a greenhouse is essential for maintaining a suitable environment for your plants to thrive.

  1. Start by cleaning: Before winterizing your greenhouse, make sure to clean it thoroughly. Remove any plants or debris that may have accumulated during the spring and summer months. This will help prevent pests and diseases from overwintering in your greenhouse.
  2. Wrap the greenhouse: Insulating your greenhouse is crucial for maintaining the right temperatures inside. Use bubble wrap or insulating material to cover the glass or plastic panels of your greenhouse. This will help to retain heat and protect your plants from the cold weather outside.
  3. Organize your tools: Proper organization is key for maximizing space and efficiency in your greenhouse. Make sure all your tools and equipment are stored neatly and easily accessible. This will make it easier for you to find and use your gardening tools during the winter months.
  4. Protect your plants: Some plants are more sensitive to cold temperatures than others. If you have plants that are not suited for winter conditions, consider moving them inside your home or insulating their pots. For those plants that can withstand the cold, it’s important to provide them with adequate water and lighting throughout the winter months.
  5. Insulate the water faucet: Frozen water pipes can cause damage to your greenhouse, so it’s important to insulate the faucet and any exposed water pipes. Use insulation material or a heat cable to protect your plumbing and prevent freezing.
  6. Overwinter your plants: If you have plants that are not actively growing during the winter, you can choose to overwinter them. This means reducing their water and fertilizer intake and providing them with minimal lighting. Overwintering can help conserve energy and ensure the survival of your plants until spring.

By following these steps, you can ensure that your greenhouse and plants stay protected and healthy throughout the winter months. With proper winterization, you can continue to enjoy gardening all year round.

1 Deep clean your greenhouse

One essential step in winterizing your greenhouse is to give it a thorough cleaning. A clean greenhouse will not only help prevent the spread of diseases and pests, but it will also create a healthier environment for your plants to grow in.

Start by sweeping or vacuuming the floor to remove any dirt, debris, or fallen leaves. Pay special attention to the corners and areas where pests might hide. Use a mild detergent solution and a scrub brush to wash the interior walls and benches. Rinse thoroughly with water to remove any residue.

Clean the glass or plastic panels with a commercial greenhouse cleaner or a mixture of vinegar and water. This will remove any dirt, algae, or mineral deposits that can obstruct light and reduce the efficiency of your greenhouse. Be sure to clean both the inside and outside of the panels for maximum light transmission.

If you have pots, tools, or other equipment stored in your greenhouse, thoroughly clean and disinfect them as well. This will help prevent the spread of any diseases or pests that may be present.

Before you start cleaning, it’s a good idea to have a plan in place. Decide what areas you will clean first and what supplies you will need. This will help you stay organized and make the cleaning process more efficient.

During the cleaning process, make sure to inspect your greenhouse for any damaged or worn-out parts. Replace or repair them before winter weather arrives. Check the insulation, seals, and weather stripping to ensure that your greenhouse will be able to withstand the cold temperatures.

Once you have thoroughly cleaned your greenhouse, it’s time to think about winterizing. Consider adding insulation to the walls, roof, and floor to help retain heat and protect your plants from frost. You can use bubble wrap, glass or plastic sheeting, or even old blankets for this purpose.

Additionally, winterize your water faucet and irrigation system to prevent freezing and bursting pipes. Drain any standing water and wrap the faucet with insulation or cover it with a faucet cover.

By following these steps and taking the time to winterize your greenhouse, you can ensure that your plants will receive the care they need during the colder months. This will not only help them survive, but also thrive when spring arrives.

2 Declutter your greenhouse

In order to properly winterize your greenhouse, it’s important to start by decluttering the space. This step will help maximize the efficiency of your greenhouse and ensure that your plants have enough space to grow during the colder months.

Firstly, remove any plants that are not suited for overwintering, such as annuals or tender perennials. These plants are not able to withstand the cold temperatures and will not survive the winter. Consider giving them away or finding a new spot in your garden where they can be protected.

Next, take the time to clean and organize your greenhouse. Sweep out any debris or fallen leaves and sanitize the surfaces to prevent the buildup of pests or diseases. This will help create a clean and healthy environment for your plants to thrive in.

If you have any potted plants in your greenhouse, now is the time to give them some thought. You can either move them to a warmer area in your home for the winter or wrap the pots in bubble wrap for insulation. Be sure to trim back any dead or damaged growth on the plants before bringing them inside.

If your greenhouse has glass or plastic panels, check for any cracks or leaks that may be letting in cold air. Repair or replace any damaged panels to ensure proper insulation. Additionally, consider applying a layer of insulating film or bubble wrap to the inside of the greenhouse to help trap heat and keep the temperature stable.

Also, take the time to winterize any water systems in your greenhouse. Drain and store hoses or disconnect them from the faucet to prevent freezing and potential damage. If your greenhouse has a water source or irrigation system, make sure to turn off the water supply and drain the pipes to avoid freezing and bursting.

In terms of lighting, consider installing supplemental lights to provide your plants with the necessary light they need during the darker winter months. LED grow lights are a popular option as they provide energy-efficient and adjustable lighting solutions.

Overall, decluttering your greenhouse is an essential step in winterizing your space. By removing any plants that won’t survive the winter, cleaning and organizing the greenhouse, and insulating the structure, you can help ensure that your plants stay healthy and thrive until spring.

3 Think about heating and lighting

When it comes to winterizing your greenhouse, thinking about heating and lighting is essential. As the temperatures start to drop, it’s important to provide your plants with the necessary warmth and light to ensure their survival throughout the colder months.


One of the first steps you should take is to start thinking about how you will heat your greenhouse. There are several options to consider:

  • Heated units: These are small heating tools that can be used to provide the necessary heat for your greenhouse. They come in different sizes and can be placed strategically to provide maximum coverage.
  • Heating cables: These can be installed throughout your greenhouse to provide heat to the plants. They are especially useful for perennials and other plants that need a constant temperature to survive.
  • Heating systems: If you have a larger greenhouse, you may need a more powerful heating system. These systems can be set up to provide heat automatically and maintain the desired temperature.

Make sure to calculate how much heat your greenhouse will need based on the size, insulation, and the types of plants you have. It’s always better to have more heat than not enough, as some plants may require higher temperatures to thrive.


During the winter months, when daylight hours are shorter, providing enough light for your plants becomes crucial. Here are a few lighting options to consider:

  • Natural light: Maximizing the amount of natural light your greenhouse receives is the most cost-effective and environmentally friendly option. Make sure to clean the glass and sweep away any dirt or debris to allow the maximum amount of sunlight to enter. Consider using bubble wrap or insulation to provide additional insulation and prevent heat loss.
  • Garden lights: If natural light isn’t sufficient, you can supplement it with artificial garden lights. These lights are specifically designed to mimic natural sunlight and can help promote healthy growth in your plants. Place them strategically throughout your greenhouse to provide even coverage.

Before making any decisions on heating and lighting tools, it’s important to have a clear understanding of your plants’ requirements and the winter weather conditions in your area. Planning ahead and considering all the factors will ensure your greenhouse is properly winterized and your plants have the best chance of surviving the colder months.

4 Turn off and insulate water outlets

As autumn approaches and the colder months start to sweep in, it is essential to think about winterizing your greenhouse to protect your plants from freezing temperatures. One important step in this process is turning off and insulating water outlets to prevent any damage that could occur due to freezing water.

In terms of water outlets, this can include faucets, hoses, and any other water sources that you may have in your greenhouse. Before the winter weather sets in, it is important to make sure that everything is turned off and drained thoroughly to avoid any potential freezing and bursting of pipes or water sources.

One suggestion is to empty any hoses and coil them up neatly for storage in a shed or another suitable location. Disconnect them from the water source and make sure to drain them completely to prevent any water from freezing inside.

To insulate your water outlets, you can use a variety of materials such as foam pipe insulation, bubble wrap, or even old rugs or blankets. Wrap these materials around the pipes or faucets to provide an extra layer of protection against the cold temperatures.

A tip from greenhouse expert Dr. Beth Carruthers of the American Botanic Council explains that it is important to not only turn off and insulate water outlets, but also to drain them thoroughly. She suggests that this will not only help prevent damage but will also ensure that you have enough water available for your plants during the winter months.

Some gardeners may choose to overwinter certain plants, such as perennials or cultivars, in a small heated greenhouse or cold frame. In these cases, it is even more important to wrap and insulate water outlets to ensure that the plants receive enough water during the colder months.

In terms of planning, it is always a good idea to start thinking about winterizing your greenhouse before the colder weather arrives. This will give you enough time to make sure that everything is properly prepared and insulated.

Knowing how to winterize your greenhouse and turning off and insulating water outlets is an important step in protecting your plants and ensuring their growth and health. By following these steps, you can help to ensure that your greenhouse remains a haven for your plants, even during the coldest months of the year.

5 Insulate your greenhouse

Insulating your greenhouse is an essential step in preparing it for the colder months. If you’re thinking about winterizing your greenhouse, then insulation should be at the top of your list. Proper insulation can help to maintain consistent temperatures inside the greenhouse, ensuring that your plants receive the maximum amount of warmth during the winter weather.

There are several steps you can take to insulate your greenhouse. Firstly, make sure to thoroughly clean the glass or plastic panels, removing any dirt or debris that may have accumulated over the year. This will help to maximize the amount of light that can enter the greenhouse during the winter months.

One option for insulation is bubble wrap. You can use bubble wrap to cover the walls and roof of your greenhouse, creating an additional layer of insulation to help retain heat. Another option is to install insulated glass or plastic panels, which provide better insulation than standard glass or plastic panels. These panels are designed to trap heat inside the greenhouse and prevent it from escaping.

In addition to insulating the walls and roof, it’s also important to insulate the floor. Use a layer of bubble wrap or foam insulation to provide an extra barrier against the cold temperatures. This will help to protect the roots of your plants and prevent them from freezing.

If you have small tools or garden supplies stored in your greenhouse, make sure to insulate them as well. Wrap them in bubble wrap or store them in insulated containers to protect them from the cold.

For greenhouses that are heated, consider using a thermal cable or small heaters to maintain a consistent temperature. These units can be placed in strategic locations throughout the greenhouse to provide additional heat when needed.

David Griffin, a greenhouse specialist, explains that insulating your greenhouse can help to extend the growing season and provide a protected environment for overwintering or starting seeds early in the spring. By insulating your greenhouse, you can create a more stable and controlled climate for your plants and ensure their healthy growth throughout the colder months.

  • Thoroughly clean glass or plastic panels
  • Use bubble wrap or install insulated glass or plastic panels
  • Insulate the floor with bubble wrap or foam insulation
  • Insulate small tools and garden supplies
  • Consider using thermal cables or small heaters for heated greenhouses

6 Add plants that need protection

If you have some plants in your garden that need extra protection during the winter months, it’s important to add them to your winterizing plan. Some perennials and delicate plants may not be able to survive the cold temperatures without some extra care.

Start by organizing your greenhouse to make sure you have enough space to accommodate these plants. Thoroughly clean the greenhouse before adding any plants to ensure a healthy start to the winter season. Sweep out any debris and give the glass a good cleaning to maximize light transmission.

Next, consider creating a sheltered area within your greenhouse for these plants. You can use bubble wrap or other insulation materials to provide additional protection. If you have a heated greenhouse, you can place them closer to the heat source to keep them warm.

When adding these plants to your greenhouse, use pots with good drainage and potting soil that is appropriate for your specific plants. Make sure to water thoroughly and avoid overwatering. Wrapping the pots with insulation material can help maintain a stable root temperature.

Throughout the winter, monitor the temperature in your greenhouse and adjust the heating if necessary. If there are extremely cold nights with frost, consider covering the plants with a frost cloth or similar material.

It’s important to know the specific needs of each plant you’re overwintering and plan accordingly. Some plants may need more light, while others may require less water. Research the individual requirements for each plant and adjust your care accordingly.

By adding these plants to your winterizing plan, you’ll be able to continue enjoying their beauty and reap the benefits of a well-protected garden come spring.

How do you overwinter an unheated greenhouse

If you have an unheated greenhouse, you may be wondering how to properly overwinter your plants and protect them from the colder weather. While it may require some planning and organization, there are several steps you can take to ensure your plants survive the winter months.

1. Thoroughly clean your greenhouse

Before winterizing your greenhouse, it’s important to clean it thoroughly. Remove any debris, weeds, and dead plants to prevent pests and diseases from overwintering. Clean and disinfect the surfaces to create a healthy environment for your plants.

2. Insulate your greenhouse

Insulating your greenhouse is essential for maintaining a suitable temperature throughout the winter. Consider adding insulation to the walls, roof, and floor of your greenhouse. This can be done with materials such as bubble wrap, horticultural fleece, or straw bales.

3. Provide adequate lighting

Since winter days are shorter and natural light is limited, it’s important to provide adequate lighting for your plants. Consider using artificial lighting, such as grow lights, to ensure your plants receive enough light for healthy growth.

4. Protect plants with pots and covers

If you have delicate or frost-sensitive plants, consider potting them and bringing them indoors for the winter. This will provide them with extra protection from the cold. Additionally, cover your plants with frost blankets or cloths during periods of extreme cold to prevent damage.

5. Monitor temperature and humidity

Regularly monitor the temperature and humidity levels in your greenhouse throughout the winter. Use a thermometer and hygrometer to ensure the conditions are suitable for your plants. Adjust the insulation and ventilation as needed to maintain the optimal environment.

6. Start planning for spring

While winter is a time of dormancy for many plants, it’s never too early to start planning for spring. Use this time to research new cultivars, update your gardening calendar, and make any necessary adjustments to your greenhouse setup. This will ensure a smooth transition into the next growing season.

By following these steps, you can successfully overwinter your plants in an unheated greenhouse. Remember to take into account the specific needs of your plants and adjust your winterizing strategy accordingly. With proper care and preparation, your greenhouse can continue to provide a nurturing environment for your plants throughout the winter months.

Does a greenhouse need to be heated in the winter

One of the common questions that greenhouse owners ask themselves when preparing for the winter is whether or not their greenhouse needs to be heated. The answer to this question depends on a few factors, including the type of greenhouse, the plants being grown, and the local climate.

Some greenhouses, such as small hobby greenhouses or unheated greenhouses, do not have a heating system installed. These types of greenhouses rely on passive heating methods, such as the sun’s warmth, to keep the temperature inside at a suitable level for the plants.

However, if you have a larger greenhouse or live in an area with particularly cold winters, it may be necessary to heat your greenhouse to protect your plants from freezing temperatures. While some cold-hardy plants can tolerate mild frost, many plants will suffer damage or die if exposed to prolonged freezing temperatures.

If you choose to heat your greenhouse, there are a few steps you can take to ensure maximum efficiency:

  1. Insulate your greenhouse: Proper insulation is essential for retaining heat inside the greenhouse. Bubble wrap, foam insulation, or insulated panels can be used to cover windows, walls, and doors to prevent heat loss.
  2. Use a heater: There are various types of heaters available for greenhouse use, including gas, electric, and wood-burning heaters. Choose a heater that is suitable for the size of your greenhouse and provides enough heat to maintain a minimum temperature throughout the winter months.
  3. Install a thermostat: A thermostat will help you maintain a constant temperature inside the greenhouse. Set the thermostat to the optimal temperature for the plants you are growing.
  4. Consider alternative heating methods: Some greenhouse owners use alternative methods such as geothermal heating or solar heating systems to reduce energy consumption and greenhouse gas emissions.
  5. Insulate the potting shed: If you have a separate potting shed or storage area attached to the greenhouse, make sure to insulate it as well to protect your tools and supplies from freezing.
  6. Clean and organize: Before winterizing your greenhouse, it is important to clean and organize everything. Sweep away debris, remove dead plants, and organize your tools and equipment. This will not only make your greenhouse more efficient but also help prevent the spread of pests and diseases.

While heating a greenhouse in the winter may require some additional effort and expense, it is a necessary step to ensure the survival of your plants and maintain a productive growing environment. By following these steps and knowing the specific needs of your plants, you can successfully winterize your greenhouse and enjoy a thriving garden throughout the colder months.


You may also like

Leave a Repl​​​​​y

Your email address will not be published. Required fields are marked

{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}

Direct Your Visitors to a Clear Action at the Bottom of the Page