The Best Greenhouses for Cold Climates Actually Worth Buying
Growing in cold climates is often a challenge when it comes to starting and growing plants during the winter months. When the temperature dips, plants die. But not anymore! Here are five favorites competing as the best greenhouses for cold climates that are actually worth your money.
People in northern climates experience a much shorter growing season. This is why greenhouses have become common in such places. Not only does a winter greenhouse help you get more yield from your land, but it also enables you to grow crops year round that are not commonly grown in your area due to extreme cold weather conditions.
Are you tired of putting in effort all year only to see your hard work go down the drain when the cold winter hits? Check out our recommendations below for the best cold weather greenhouses.
Top 4 Best Greenhouses for Cold Climates in 2022
1. Riga IV 10′ x 14′ Commercial Greenhouse
✔ Aluminum Frame
✔ 8 mm & 10mm Thick Polycarbonate Glazing
✔ 10ft x 14ft
✔ Warranty: 10yrs panels / 15yrs frame
Riga IV Greenhouse Review:
The Riga IV greenhouses make a perfect fit for cold climates. Their “onion” shape provides added strength, resists wind, and doesn’t allow for snow to build-up on it. It’s no wonder they have such a good warranty. The main body has 8mm thick twin-wall polycarbonate panels, while the front and back boast 10mm thick wall panels for added strength.
The lockable doors and two automatic roof windows provide plenty of ventilation. It also uses top-of-the-line insulation with a R or K-value of 3.0. This European-style greenhouse was designed and manufactured in Germany.
2. ClimaPod 9′ x 12′ Hobby Greenhouse
✔ Aluminum Frame
✔ 4 mm Thick Polycarbonate Glazing
✔ 9ft x 12ft
✔ Warranty: 10 years
ClimaPod Hobby Greenhouse Review:
The ClimaPod hobby greenhouse is made from a heavy-duty aluminum frame and 4mm thick, twin-wall polycarbonate wall panels. Features of the ClimaPod include 4 automatic and 4 manual window openers and 2 solar powered thermostatic fans.
There are locking, sliding doors and the included 2-tiered aluminum shelving is a real nice touch. The shape helps reduce the likelihood of snow staying on the roof and, the manufacturer claims it’s durable and can hold over 10″ of snow.
3. Palram Bella Hobby Greenhouse (8′ x 12′)
✔ Aluminum Frame
✔ 6 mm Thick Polycarbonate Glazing
✔ 8ft x 12ft
✔ Warranty: 5 years
Palram Bella Greenhouse Review:
The Bella greenhouse made by Palram only has a 5yr limited warranty, shorter than others in its market. It is made with 6mm thick, twin-wall polycarbonate panels and its shape helps provide wind resistance and less likely that the full weight of a snowfall is seen by the greenhouse. Much of the snow just slides down the sides.
One of the nice features of this winter-ready greenhouse is the galvanized steel base that adds structural support to the aluminum frame. Other features include lockable doors, adjustable roof ventilation, and an installation video.
4. Solexx Harvester Greenhouse (8′ x 12′)
✔ Composite Frame
✔ 3.5 mm Thick Polyethylene Glazing
✔ 8ft x 12ft
✔ Warranty: 8 years
Solexx Harvester Greenhouse Review:
The Solexx Harvester greenhouse is Made in the USA! The heavy-duty composite frame also sets it apart from the competition. The Harvester is made in 3.5 mm or optional 5 mm thick panels for colder climates.
The lean-to design of the Harvester lends itself to be place along-side a house or barn for added insulation. The slick polyethylene glazing material tends to keep snow off itself. No foundation is needed and shelves are built-in. This is a nice American-made option for looking for something different.
How Winter Greenhouses Work Year Round in Cold Climates
A cold climate greenhouse is a great investment for gardeners who want to extend the growing season or live in areas where the temperature drops during the winter months. Greenhouses work year round because they offer protection against the elements, shelter from wind and provide warmth from the sun. They can do all these even when outdoor temperatures are too low to support plant life.
The key is to find a way to keep the greenhouse environment within the plant zone. There are a few different ways that this can be done. However, when done right, greenhouses can keep your plants healthy and productive year round, even in a northern climate like those in Alaska and other northern states.
Cold Weather Greenhouse Considerations
These are the features and details you’ll want to keep in mind when shopping for cold climate greenhouses. Unlike small, hobby greenhouse kits made for anywhere, you’ll these considerations will ensure you don’t overlook something critical.
There are many sizes available on the market that range from small cabinets to large structures with multiple rooms. A greenhouse’s size will likely be the most important decision you’ll make, and will almost certainly help determine your budget.
So, what size should you go for? Well, that depends on a few things. How much space do you have in your yard, where you do you plan on putting it, and how much interior space do you really need for planting? Don’t forget that you’ll likely want to add more in the future, not less, so allow for some extra space to expand in the future.
We recommend considering a greenhouse that is roughly 20% larger than you think you ultimately need. Don’t forget about added space for any thermal mass or heating devices that you might implement.
Although it seems like bigger might always better, consider that you’ll also need to figure out how to keep the entire space warm. If that entails heating, costs will be higher if your greenhouse is larger.
Glazing Materials and Thickness
We’re all used to seeing greenhouses with tons of clear surfaces, often called glazing. These are the surfaces of the greenhouse that allows light to pass through, heating the inside. Glazing typically consists either of glass or plastic, most commonly polyethylene or polycarbonate.
The best greenhouses for cold climates or those with winter considerations, will almost certainly have a multi-layer glazing material. This allows for maximum R-value (a material’s ability to resist heat transfer), while also allowing as much light as possible to pass through to assist in warming the inside. They also come in varying thicknesses. For the most part, thicker is better.
Here are some pros and cons of these 3 materials:
A greenhouse made entirely of glass is typically what most of us have in mind when we think about them. Why wouldn’t we? Almost every time you see a greenhouse in a movie or on TV, it’s beautiful and made entirely of glass!
Glass really is a decent material to use for glazing on a greenhouse, but in the north, it must certainly be double-pain glass or you won’t have enough insulation. Really, the best part of glass is its aesthetics.
Glass does allow lots of light transmission, which is a good thing. But, besides that, glass gets super expensive. It also doesn’t diffuse the light, and it can be fragile.
Another very popular material used in greenhouses is polycarbonate. It’s the favorite for most, especially in the north where it gets pretty cold in the winter.
Polycarbonate greenhouses are often better because the glazing is energy-efficient, durable, and has both good light transmission and light diffusion. It’s also less expensive in general than glass. What’s not to like? Well, it’s not a clear as glass, so maybe not as pleasing to the eye. However, functionally, nothing really beats it. It also comes in many different thicknesses so you can get exactly what you want.
While polyethylene is widely used as a greenhouse covering, it’s better suited for areas that don’t get very cold during the winter, or someone looking to just “extend the season”.
Polyethylene is a thin plastic film. It’s a cheap material that’s lightweight and easy to work with. The downside of poly film is that it has very little durability against the elements and it provides no rigidity to your structure.
Worse yet, it doesn’t allow as much light to pass through as glass or polycarbonate do, and it insulates your plants less too. Of course, these are the two most important considerations when trying to determine which material will make the best cold weather greenhouse.
The best greenhouse materials for cold climate areas would be either glass or polycarbonate. For the most part, polyethylene is just not going to be thick enough or have adequate insulative value to really protect your plants. That’s not to say it’s not ever used, but it’s certainly more of a temporary solution.
Proper insulation will help keep the space warm during the winter and cool during the summer months. To increase performance, all surfaces that are not intended to absorb heat (glazing) should be insulated well.
Insulation ideas range from insulating blankets at night to sealing all joints/cracks with weather-stripping and caulk. Reflective foam insulation materials are also popular.
Another smart consideration some make is to use airspace between layers of the glazing materials to produce a built-in airgap layer of insulation.
Keep in mind that up to 80% or more of heat loss occurs at night when the sun is not actively beating down on your greenhouse.
This 5mm closed cell polyethylene foam is sandwiched between two sheets of premium grade aluminum. It’s very effective, reflecting 97% of radiant energy and has an R-value up to 15.67 in a single layer. According to the manufacturer, it also acts as a vapor barrier, preventing condensation.
Ventilation systems vary by type of greenhouse, but all make sure you’re getting enough fresh air while still keeping outside temperatures and humidity at bay. In fact, greenhouses placed in colder climates often consider winter conditions when buying or building, but rarely think extensively about how to control conditions on the opposite end of the spectrum.
Don’t forget that since they’re often designed to absorb and trap heat in the winter, the same happens in the summer months, and this can cause them to get too hot. Proper ventilation is important and necessary for those hot summer days.
Winter Greenhouse Heating
Even on warm, sunny days, temperatures can dip below freezing at night. During the winter months in cold climate areas of the world, heating and heat retention are the main concern. Even though glazing allows for the sun to pass through and warm the space during the day, temperature loss through the cold nights can sometimes make this seem like a futile task.
This is often a topic that’s met with a solution that is multi-fold, using both active and passive heating principles. Heating methods can range from solar heat storage with thermal mass to active solar or subterranean heating.
However, a greenhouse should almost certainly also have a conventional heater as a backup heat source when these other methods are not able to keep up with the demand due to extremely low temperatures. These are rarely included with a greenhouse kit, so don’t overlook this expense when planning your budget.
This greenhouse heater can heat up to 120 sq-ft and is so convenient to use at 110v AC power. This 1500w heater has a stainless steel housing and comes with a digital thermostat. It’s perfect for circulating warm air in the winter time to remove any cold air pockets.
Greenhouse Construction vs. Price
If you’ve done any amount of research, you’ve probably seen all the hobby greenhouse kits online retailers and big box stores have in the $500-$1000 range.
These are great options where they fit consumer’s needs, but the reality is, these really aren’t intended to be permanent, long-standing options in cold climate areas that see heavy snow and extreme temperatures.
When compared to their more durable, commercial counterparts, you’ll find that their frames and glazing are often made of thinner, more inferior materials. The construction of these small greenhouse options is not the same. There’s nothing wrong with that, they just aren’t built to last year after year in the harsh climates we’re talking about here.
Larger, more durable commercial models make better cold climate greenhouses, especially if you can find one with a galvanized steel frame. They’re better suited for extreme weather conditions, heavy snow loads, and everything else that comes with the northern climate and colder parts of the country if you want a year round greenhouse.
So, what should you expect to spend on a good, quality cold climate greenhouse? Probably several thousand dollars for the greenhouse kit itself. Don’t forget about adding great insulation, passive heating, and land preparation that will all add to the cost. Building greenhouses right the first time will still cost you less in the long-run.
Greenhouse Location and Thermal Mass
Even the best greenhouses for cold climates require some work and know-how on your part. Here are a few things you’ll need to keep in mind when preparing your project; location and thermal mass. These aren’t things that you just buy as a feature of a greenhouse kit.
Placement / Cold Climate Greenhouse Orientation
An often-overlooked topic, the orientation of a greenhouse in cold climates can impact your success as much or more than almost any other factor. To optimize your greenhouse for winter conditions, orient the longer, glazed side towards the south. During the shortest daylight times of the year, a south facing roof will maximize the amount of sunlight passing through the glazing and entering the greenhouse.
Of course, the opposite is true too. Insulating the opposite side of the greenhouse where the least amount of sunlight enters will help ensure maximum heat retention. This is the reason; you’ll sometimes see one-sided or “lean-to” greenhouses in the extreme cold climates. In fact, it’s not uncommon to see the Northern side of the greenhouse attached to another building such as a house or a barn to provide the utmost insulation.
Thermal Mass / Passive Solar Greenhouse Design
Passive solar greenhouses have added thermal mass, which helps keep them warmer longer. Thermal mass is a material that absorbs heat during the day through sunlight and releases during the night in an attempt to keep the area warm when sunlight is no longer present. This basic method of heat storage, called passive solar energy, can save you tons of money on supplemental heating costs in cold climates.
Water is probably the most common thermal mass material used in a passive solar greenhouse since it’s readily available and free of cost. It’s stored large, dark-colored barrels and placed in direct sunlight, along the north wall typically makes the most sense. Keep in mind that water freezes, so it’s largely used in conjunction with other heating methods.
You should consider utilizing a remote temperature & humidity sensor. They provide constant monitoring of your greenhouse’s air and environment. This will ensure you’re aware of what’s going on before any issues arise, something very important if you’re trying to be more self-sufficient.
Other inexpensive materials used for heat storage include masonry, stones, and even the earth, or dirt.
With Temp Stick, you can remotely monitor your greenhouse’s environment from anywhere and at anytime. Complete with data logging and historical statistics, you can feel confident that your plants are in good shape. Set hi/low extremes and receive alerts via email or text message 24/7.
Cold Weather Greenhouse FAQs
Do Greenhouses Work in Winter?
Contrary to popular belief, greenhouses work great in winter. The key is to make sure you have the right greenhouse for your climate. The perfect greenhouse for cold climates should have considerations for insulation, heating, and setbacks. Setbacks prevent snow from piling up against the walls.
How to Keep a Greenhouse Warm in Winter?
Greenhouses provide heat for your plants by trapping solar heat through their transparent roof and walls. Heat storage methods using thermal masses and insulation help. This may not be enough heat for certain areas of the country during the winter months however. If this is the case for you, there are ways to add supplemental heating. If you’re just using a small, portable greenhouse kit, this may not be necessary. Grow lights might be a good option in this situation.
What to Grow in a Winter Greenhouse?
There are tons of plants that work well growing them in a winter greenhouse. Typically winter vegetables include things like lettuce, onions, carrots, and strawberries, but this is certainly not an exhaustive list. Leafy greens are also popular plants that can be grown year round in a greenhouse garden.
As long as you can keep the temperature in the plant zone, the sky’s the limit! Go ahead, step out of our comfort zone and try something new when gardening.
What Temperature Should a Greenhouse Be in Winter?
Classically, greenhouses are built to maintain temperatures between 50F and 70F degrees in the winter (although this can vary significantly depending on the type of winter gardening you’re focusing on). But there is an optimal temperature range for plant growth, called “the plant zone”. This zone varies with each plant type, and it’s extremely important that growers maintain their plants within this zone.
Do Greenhouses Need to be Heated?
If you’re looking to grow in colder climates, it’s best to make sure that your greenhouse is heated. This can help protect your young plants from frost and keep them healthier. If you don’t want your greenhouse to get too hot during the summer months, it’s also a good idea to make sure that it has sufficient ventilation. Having the right amount of light and air ventilation will allow your plants to grow stronger and healthier.
The right type of heating system for your greenhouse will depend on the size of the structure and how much heat you need at any given time. You can use electrical heaters, oil or gas heaters, or even wood stoves if needed. However, make sure that whatever heating system you use is properly ventilated as well or else the air might get too hot inside, potentially hurting your plants!
What's the Difference Between DIY Greenhouse Kits and Building?
Greenhouse kits are readily available and are seriously the most convenient way to build the best greenhouses with the least amount of energy expended. They come with a frame, panels, and a door. You just have the prep the ground for construction, and away you go, an easy greenhouse garden ready for your plants.
Building your year round greenhouse will certainly require more energy on your part. Although you can find greenhouse plans on the internet, you’ll want to double check that the construction and materials are up for the snow loads in your climate & environment.
Of course if you decide to go the DIY greenhouse route, you can make sure it’s insulated the way you want, it’s perfect for the ground you’re working with, and it allows just the right amount of light for your favorite plants! Just make sure you get started in the spring so you’re ready long before winter gardening comes around. Greenhouse kits do make install much easier.
What is a Hoop House? Are They Good for Colder Climates?
A hoop house is a simple, cheap version of a greenhouse. They are NOT a good year round option for colder climates due to their light-duty construction. They are intended for a cheap option, something that will extend the growing season beyond just the spring and summer.