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Do Greenhouses Stay Warm in Winter? What You Need to Know

Although it’s not very common, you can use greenhouses to keep plants warm in winter. However, there are some things that need to be taken into consideration if you want your greenhouse to do the job. Greenhouses are used to extend the growing season of plants, but do they also work to keep them warm during cold months?

Do greenhouses stay warm in winter? The answer is yes as long as you know how to follow some important steps or techniques.

In this blog post, we will discuss how you can make this happen and how you can keep your plants safe during cold winter nights and days.

Read on!

What is a greenhouse?

plants and flower pot placed on the table in greenhouse

A greenhouse may serve both as a heat sink or house and as a cooling house for different species of plants. It must have a minimum temperature of at least 55 degrees Fahrenheit. The maximum temperature in a typical day can be as low as 92 degrees year-round.

Greenhouses work to keep plants warm during the cold season when the sun’s energy is down. This is done by using some techniques and following some steps.

One of the most important things to do if you want your greenhouses to be effective for winter gardening is to make sure that you provide enough insulation and protection for your plants. You also need to see to it that the greenhouse in winter stays dry at all times.

The Popularity of a Greenhouse

Today, a greenhouse is popular in botanic gardens, resorts, botanical institutes, and places that are classified as having tropical or therapeutic environments. It also functions as enclosed spaces to produce plants for special purposes, such as heated crops during winter months or high-value herbal crops for medicinal purposes.

By increasing the availability of CO2 through heating up the air that circulates through the plant beds or by adding more water vapor into it through fogging systems, tender plants grow larger and require less frequent watering from the greenhouse operator.

What is the main purpose of a greenhouse?

greenhouse in a glass wall

The purpose of greenhouses is to offer protection for your favorite plant against changes in climate.

The traditional greenhouse is used as an extension of one home’s living room where the temperatures inside and the humidity are maintained at all times for year-round enjoyment.

An entire greenhouse does a great job of turning dark and cold winter days into wonderful opportunities to make your plant happy. Temperatures keep on changing all year round, which is why you have to prepare your greenhouse at all times.

Be sure to check the soil temperature and thermal mass of your greenhouse to ensure that it is ready to provide better protection for your plants.

What can a greenhouse do for a plant?

A greenhouse helps plants grow faster and healthier by increasing their growth, improving the yield, and leveling up the quality of harvested produce in colder or warmer climates.

Other than those mentioned above, greenhouses can do a lot of stuff such as watering and fertilizing a plant, providing better protection against pests and diseases, increasing the temperature inside, and growing vegetables or different varieties of crops all year round.

What is a good temperature for a greenhouse?

Hot water heating greenhouse

According to the UST criteria, a greenhouse or hothouse must have at least a minimum of 55 degrees Fahrenheit all year road. You must not allow greenhouses to heat up to 90 degrees Fahrenheit or less. This can be dangerous for your entire botanical collection.

How do you control greenhouse temperatures?

There are several ways to control greenhouse winter temperatures, but by far the most common are heating, ventilation, and insulation. The nice thing about greenhouses is that you can do all three at one time.

If the exterior wall boards do not provide enough warmth, you may need to do place panels on top of the wall-board and install a single layer of hard insulation (R5+) in the enclosed garden space. This is less than desirable as it reduces your available growing area and costs more energy for heating than insulating from within.

See Related: Best Greenhouse Plastic Covering

Setting Up A Greenhouse

Greenhouse with flowers, plants on plant rack

There are two cool reasons to use a greenhouse, such as providing protection for growers and making sure that the outside temperature will not cause any harm to the plants inside it.

The only disadvantage is that your growing area will be less insulated, but you may bring in more sunshine and heat without overcompensating with space heaters.

Permanently place a row of exterior wall panels with ½ foam permanently insulated between each of them. You have an unheated sunroom that can stay warm up until late November.

Shading windows, keeping them closed during evening hours, and shutting doors before sunset will help conserve heat indoors to allow the greenhouse to meet its minimum nighttime temperature during the winter weather.

How can you start a Greenhouse DIY?

First, collect what you need for your greenhouse. Consider the size of the area where you’ll be constructing it. You will need to take note of any structures already in place. This is why you need to ask yourself if whether or not you have to do more work to remove these structures.

From the materials you have, do some rough sketches so that you get an idea of what your greenhouse is going to look like along with how it’s constructed. Remember that the goal is to make greenhouse warmers so you can make plants happy.

Once you have the plans, collect the tools and materials needed to do the work. If you do not have a saw, you can cut large pieces of wood to size with a handsaw and assemble the whole thing with nails. But if you do have a saw, use it because cutting pieces of wood in half or at angles is much easier than trying to do it without one.

See Related: Best Off-Grid Greenhouse Heating Systems

What do you do with a greenhouse when the weather changes?

When the weather starts to get cold, most people choose not to do anything with their greenhouses. If it’s going to be cold for a short period of time, your plants will be fine inside it.

However, if it looks like the cold weather is going to stick around for an extended period of time, then you do need to take extra steps to ensure that you can make your greenhouse stay warm during cold temperatures.

See Related: How to Choose the Right Greenhouse Size

What do you do with a greenhouse when it starts to get cold?

Greenhouse covered in snow

One of the things that you can do is to make your greenhouse warmer by using an insulation material. This will help keep your greenhouse in winter become more ideal for your well-beloved plants.

However, if the situation changes and there are warmer months of winter, then do not worry. Insulation is reversible. If you do not want to use insulation any longer, then you can just take it down.

See Related: Best Mini Greenhouses | Portable Options to Buy

When does a greenhouse stop working?

If the temperature inside the greenhouse is too low for whatever reason or it does not have enough insulation, then you need to do something about this.

One of the easy ways to fix it is through the use of an electric heater to improve the temperature inside. Do not worry as this will not drive your electric bill up.

The winter protection techniques that are used to keep an unheated greenhouse warm in winter will not be effective if the days are cloudy. This is because the greenhouse does not get enough sun rays or sunlight or warmth during such days when the temperature is close to a freezing point.

See Related: Greenhouse Costs Guide

What happens if your greenhouse is damaged?

The important thing to do when your greenhouse is damaged must be done as soon as possible. The longer it takes, the harder it will be for your botanical collection to recover.

If your greenhouse is flexible, try removing snow from its roof first, before assessing whether it can be repaired or needs to be replaced entirely.

If your greenhouse is made out of plastic, do not try to clear off snow with a shovel or broom. You’ll do more damage than good if you do this because the roof will most likely break apart at the seams.

Instead, grab a dull tool like an ice scraper and lightly go over it until all of the snow has been removed.

If your greenhouse cannot be repaired, do not do anything to the plants. They can survive a little bit of cold weather because they are covered in snow.

See Related: Best Greenhouse Fabrics


different plants growing inside a greenhouse

Greenhouses do not have to be heated in the winter. However, if your greenhouse has insufficient insulation or is too chilly for whatever reason, you should take measures now to keep it warm throughout the next several months of winter so that your plants are not harmed.

Greenhouses do not stop working during winter unless something happens. If they do, be sure to act fast. If you want to learn more about garden tips, sign up for our newsletter.


How can I heat my greenhouse for free in the winter?

Sometimes people try to heat their greenhouses with an electric heater, but this is a really bad idea. A greenhouse acts as a gigantic convection oven, so instead of heating it from the inside, you are better off insulating the outside walls with Styrofoam panels or buying some Solar PV Panels. This way you can harness solar power to keep your greenhouse warm all winter long!

How warm is an unheated greenhouse?

Warm enough to do some cool things, but you’ll need some supplemental heating too.

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