The many types of Greenhouses

While there are a few basics to greenhouses, there are many variations based on those principles. If you were to look right now at every greenhouse available to you, you’d probably wonder why there were so many. However, knowing the types of greenhouses and all the structural materials available will make all the difference between choosing the right greenhouse or making a costly mistake.

While they all share the same principles, some greenhouses are better suited for your area than others. So before we get into it, start getting a rough idea of what you want to get out of your greenhouse. Of course, you should have an idea of what you want to grow. You’ll also want a good idea of how long you want to make your growing season. Do you want to extend it a couple of months, or do you want year-round usage? Then there’s the matter of where you live and what space you have available to you. How much sun does this area get? Do you get violent windstorms? Extreme winters? You should even get an idea of any regulations that are in place before putting a structure on your property. These things are going to play a role in the greenhouse you have, so keep them in mind while you go through all the types of greenhouses.

TYPES BY PURPOSE

You want your greenhouse to serve its purpose, so this accounts for some variations. There are commercial greenhouses that are for professional growers like farmers. Educational greenhouses are those structures growing to study new methods and try different growing conditions. There are also conservatories, which are greenhouses but are used for gatherings and social settings. The structure we will look at is a hobby greenhouse.

Now, let’s turn to your growing season. This will determine if you are going to have a cold, cool, warm, or hot greenhouse.

• Cold greenhouses or cold frames:

If you aren’t planning on using alternate heat or insulation, you will run a cold greenhouse. These are good for starting your growing season a bit earlier and extending it into the fall, but that’s it. If you store any plants here for the winter, they should be winter-hardy.

• Cool greenhouses:

These greenhouses’ lowest temperature is going to be around 45 to 50 °F. This is the perfect setting if you want to store plants that can’t tolerate the cold winter.

• Warm greenhouses:

The lowest temperature here will be between 50 and 55 °F. Any plants that are sensitive to lower temperatures will be safe here, and you might do some light growing.

• Hot greenhouses or hothouses:

Your lowest temperature here is 60 °F. This tropical setting is magnificent for tropical plants or if you want to do year-round growing.

Freestanding Greenhouses

Freestanding greenhouses are going to be ideal for what you want. These are the structures that aren’t connected to a wall.

• Conventional:

If anyone mentions a greenhouse, you likely think of a structure with a gable roof. While it looks like a simple shed with glass glazing or polycarbonate, it is a solid structure, and there is plenty of room to grow your garden.

• A-frame:

The design of this greenhouse lives up to its name. It’s a triangular structure that uses the minimum number of materials. It is fairly narrow, which makes working space and airflow common issues. However, this is one of the more popular DIY designs.

• Hoop house:

This is another popular DIY design that looks like half of a hoop. The construction of a hoop house is relatively cheap because of the framing (aluminum or plastic) and glazing (two-layer plastic) materials.

• Quonset:

A hoop house is basically a Quonset building since the designs are similar. However, it is a popular design because there is more room to move around compared to the A-frame.

• Gothic arch (onion-shaped):

The shape is a lot like the Quonset, except this will have a pointed top to look like an onion or a water drop. While the shape is aesthetically pleasing, it comes in handy if you live in an area with a lot of snow and wind.

• Victorian:

This design was the one that was used before as a greenhouse and a social meeting spot. Because of that, its design stands out as elegant compared to other greenhouses.

• Geodesic dome:

A greenhouse design that is easily recognizable from the triangular panels that make up the dome. These angles and measurements are very precise, but that makes for a structure that can withstand virtually any condition. They are roomy, have high energy efficiency, and have better light transmission than other greenhouses.

• Sawtooth:

Another popular design that allows a lot of natural light to come in. The name comes from the roofline, which is made of a series of triangular peaks.

• Shade house:

As the name implies, this greenhouse is for growing plants in the shade. Material-wise, this structure is typically lighter with plastic or cloth that let the sun filter in without directly hitting the plants.

Attached Greenhouses

You might want a freestanding structure, but your property says otherwise. You can still have a greenhouse if you have a smaller yard, or you need to be efficient with the yard space you do have.

• Lean-to:

These greenhouses will share a wall with your house or your garage, which is perfect for smaller spaces. The wall will provide stability to the structure. There will be more on this, but your wall should be south-facing so the greenhouse gets sunlight all day.

• Window:

Even if you don’t have yard space, you can use a window greenhouse. This is just an extension to your normal window that gives your plants the sunlight they need without taking up all the room.

• Window farm:

Urban areas can still take advantage of some greenhouse techniques with this vertical growing system. It uses room temperature and some principles from hydroponic gardening.

Portable Greenhouses

While you want something solid, portable solutions should be mentioned. These structures are usually inexpensive, and you can use them wherever you want in your yard. Going back to temperature, these greenhouses will be cold frames or just raised garden beds.

PROS AND CONS OF STYLES

Now that you are familiar with the names and the general idea behind greenhouses, it’s only fair to give the pros and cons of each one. This is also going to give you the pros and cons behind materials. Remember that every detail is going to count when investing in such an extensive structure.

Lean-to Greenhouse

Again, this structure uses a (preferably south-facing) wall of your home or garage for stability. This gives you two to three sides for your glazing and roof. Most of these structures stay at 12 feet and under, and if you have a long enough wall, you can extend your growing space.

• Pros: Having this against your wall means the greenhouse is closer to utilities like water and electricity. By needing less space to set up, you will save on building materials.

• Cons: A smaller structure means you have a very limited space for growing, and without a south-facing wall, you’ll be struggling with keeping light on your plants. It is also harder to control the temperature in a lean-to because of the wall support.

A-frame Greenhouse

You may hear the term “ridge and furrow,” which is just connecting A-frames in a row. You can also consider these same pros and cons for the conventional greenhouse. They are fairly easy to assemble, and you can do it with just wood and plastic sheeting.

• Pros: There is ample space for growing plants, and the design can save on energy costs. Thanks to the sloped roof, snow and rain are not an issue for building up on your roof.

• Cons: Since this is a freestanding structure, you will need to have a decent-sized area for the greenhouse that will provide it with plenty of sunlight. Tight corners are not the best place for airflow, so you will have to be mindful of what plants are in your corners. Of course, the bigger the greenhouse you have, the more costly it will be to set up, especially if you use another kind of glazing.

Gothic Arch Greenhouses

The water-drop look of this greenhouse will liven up any backyard, and the only thing you really need to think about is how much you’re willing to put towards this design.

• Pros: Since the Gothic arch is used for both hobby and commercial use, the size of your greenhouse is up to you. Again, they are appealing, and there will be no buildup of snow or rain because of the roof shape. Also, the roof design eliminates the need for trusses, which can help with the overall expense.

• Cons: Compared to other greenhouses, you are going to use more materials, especially with glazing. There are also tight corners here, so be mindful of your planting layout.

There are also two other greenhouse designs to be aware of. These are the even-span and uneven-span greenhouses. Even-Span Greenhouse

Even-span greenhouses have two sloping roofs that make the structure itself distinct; think A-frame with large slopes.

• Pros: This design can fit any size you are looking for, which can make for a spacious greenhouse with many plants. The shape itself will let you keep a uniform temperature throughout the greenhouse, and the roof will keep snow and rain from accumulating.
• Cons: These can be more expensive to set up, and you’re going to need to consider an alternate heating system to avoid this being a cold-frame structure.

Uneven-Span Greenhouse

The name gives it away, as there is only one roof that slopes down. Typically, the longer roof is completely transparent for light transmission.

• Pros: Wind is no issue for the structure, and you will get plenty of light for your plants. These designs are also long lasting.
• Cons: Uneven-span greenhouses are meant for hilly areas only, so they will not be ideal for your typical backyard.

PROS AND CONS OF FRAMING MATERIALS

No matter the design, materials matter, whether you buy a kit or build your own greenhouse. Your greenhouse needs a sturdy frame. By using materials that won’t hold up to the conditions of your area, your greenhouse will get weak over time and eventually collapse.

Pipe Metal

Pipe metal will typically be made from steel or aluminum, and these are going to be heavy-duty materials, which means it’s going to take a long time before your greenhouse is structurally weak. If you go for a pipe metal frame, you want to make sure you know the exact metal that was used because some metals will corrode faster than others.

• Pros: Metal is very durable, which means you will have something that can withstand the elements. Metal frames are also ideal for areas that have extreme heat in the summer.
• Cons: The only real drawback to pipe metal is that it can get very expensive, especially for larger structures.

Wood

This material is mostly used for greenhouses that are storing plants until the warmer spring. The best part of this framing material is that wood is readily available in most areas, and it’s easy to work with for those who like DIY.

• Pros: Again, wood promotes thermal efficiency, so it can keep your greenhouse warmer during the winter. Besides being environmentally friendly, wood frames can make for attractive greenhouses. It is also much easier to build and make repairs when you use wood.
• Cons: If you don’t have a source of wood near you, prices can easily skyrocket. Wood also needs to be treated to avoid insect invasions, which brings up its own downside, as some treatments can release fumes when heated that can harm your plants.

Plastic

Plastic will make for an impressive frame at a low cost. It is a sturdy material, especially for areas with little wind.

• Pros: Plastic is affordable, and with the many add-ons and extensions, you can make almost any type of greenhouse structure. It’s easy to clean, and it avoids the damages that could affect wood and the corrosion that happen with metal.
• Cons: If you’re aiming for an enormous structure, plastic is going to be something to avoid as that can become a flimsy structure. Areas with high winds will want to avoid plastic completely since the building could easily blow over. Even regions with extreme heat will want to avoid plastic since it can easily warp, especially if you have hanging plants.

PROS AND CONS OF GLAZING MATERIALS

There are several materials used to cover a greenhouse. This also needs to be taken into consideration when thinking about where you are and what you want to get out of your greenhouse.

PVC or Polyester Plastic

This is one of the most popular glazings out there. Typically, plastic sheets used as glazing will come in two sheets for a bit of added durability.

• Pros: Plastic sheets are readily available and cheap, which is a big help for DIY greenhouses. They will let enough light into your structure and keep heat in during the chillier months. When covering your greenhouse, this material is lightweight, so it makes setup a breeze.
• Cons: Over time, the sheets will lose durability and become more prone to damage, so they will need to be replaced. Depending on your region, this replacement can take anywhere from two to four years.

Glass

The other common glazing for home greenhouses is glass. It provides maximum light transmission for healthier plants.

• Pros: With all the light getting to your plants, you will have a greenhouse that works at maximum efficiency. Glass also gives the greenhouse a more appealing look if you want something that works while being aesthetically pleasing.
• Cons: Glass is going to be expensive, especially if you’re building a large greenhouse. This glazing is also going to need regular cleaning to keep the most light going to your plants. Depending on your region, the summer sun might be too intense for your plants, so glass greenhouses will need shading.

You might wonder about other materials, and they are out there. There are harder plastics and even acrylic panels for greenhouses. While these are great alternatives to glass, they can be even more expensive. These costs might come down eventually, so be sure to price out materials before you buy them. Another glazing is fiberglass. Fiberglass works by diffusing sunlight, so while it can provide the right temperatures, it isn’t giving efficient lighting. With fiberglass glazing, it will break down over time and be less useful. You would need to replace it, which will be more expensive than just replacing plastic sheets. However, the biggest drawback is the lighting that it would provide for your garden.

This should wrap up the most basic elements of greenhouses. Now that this information is in your hands, it’s time to get your thumbs green, and the first step to this is planning for your greenhouse garden.