Types of Greenhouses
The type of greenhouse structure determines the productivity and efficiency of your gardening activities. New to greenhouse gardening? Don’t you worry—this section will examine the different greenhouse designs and highlight the advantages and disadvantages of each structure. It will make it easier for beginners to choose the right structure based on their needs.
As a plant grower, you need to understand the efficiency of plant production and control of environmental conditions. Choosing the right greenhouse will enable you to create an ideal working environment for your vegetables, herbs, and fruits. It also allows you to create a plant growing plan that ensures you meet the specific needs of your crop.
These designs are based on the materials, shape, utility, and construction process. Most designs are classified as:
- Lean-to greenhouse structure
- Even span greenhouse structure
Freestanding or independent structures
- Uneven span greenhouse structure
- A-frame greenhouse structure
- Quonset greenhouse structure
- Gothic arch greenhouse structure
Gutter connected structures
- Ridge and furrow type greenhouse
- Sawtooth greenhouse
Lean-to Greenhouse Structure
Just like the name suggests, a lean-to greenhouse structure is built leaning on the side of another structure. It is classified as an attached greenhouse structure, meaning that the roof of the greenhouse connects to another building. You don’t have to build all the four walls of the greenhouse because, by design, it shares one of its walls.
The structure should face the right direction to obtain adequate sunlight exposure. It should mostly face the southern side and the roof should have the best covering material. a lean-to greenhouse is ideal for growing herbs and vegetables.
This structure was common during the Victorian period, and it is one of the traditional structures available. Building against the wall offers additional support to the structure, making it strong and wind resistant. The wall also absorbs heat during the day and releases that heat at night, which helps to maintain the temperature of the greenhouse during the cool nights.
If you’re planning to use lean-to structure, you need to put the height of the structure into consideration together with any metal base. This ensures the ridges do not come in contact with any windows or drainage pipes in the principal building.
- Cost-effective: This type of structure is less expensive compared to other greenhouse structures.
- Minimize building materials: The design is built against an existing wall, thus saving you on building material for four walls. It also minimizes roofing material requirements, since the design makes the best use of sunlight.
- The structure is constructed close to water, electricity, and heat.
- Limited sunlight: Building lean-to structure against a house or garage limits the amount of sunlight to only the three walls. It will also have limited light, ventilation, and minimum temperature control.
- Limited to the building orientation: The best structure should be on the southern exposure. The height of the building or the supporting wall affects the design and the size of the greenhouse.
- Temperature control: It is difficult to control the temperature of the structure because the wall absorbs a lot of heat during the day and distributes it for use in the cool nights. Some translucent covers lose heat more rapidly, making it difficult to control the heat.
- Foundation: You need to build a strong foundation for this greenhouse to last long, especially when using glass with the lean-to greenhouse.
Even Span Greenhouse Structure
Even span is another attached type of greenhouse, and it attaches more to promote plant growth. This standard structure is attached to a building, and its roof is made of two slopes of equal length and width. The structure can allow you to plant two to three rows, with two side benches and a wide bench at the center.
Even span design is more flexible and has curved eaves to boost their shape. Due to its great shape, there is plenty of air circulation in the greenhouse, thus making it easier to control temperatures. You also need to have an extra heating system especially when the structure is far away from a heated building. The heating system is especially important during the winter season.
- It provides enough space for the growth of plants and vegetables.
- It is easier and more economic in construction, making it the most popular design for a greenhouse.
- You have easy access to water and electricity within the building.
- High cost of construction and heating system compared to the lean-to structure.
- Reduced sunlight exposure due to the shadow from the house it is attached to.
Uneven Span Greenhouse Structure
In this structure, the roof is made of uneven or unequal width. The greenhouse is constructed such that one rooftop slope is longer than the other, making the design suitable for a hilly terrain or when you want to take advantage of solar energy.
Uneven slopes are laid so the steeper angles of the greenhouse face to the south. The transparent section should face south, whereas the opaque side of the greenhouse should face north to conserve energy.
Uneven greenhouses are no longer used because most farmers prefer setting up a greenhouse on a flat land.
- As mentioned, this greenhouse is in a hilly areas.
- There is no obstruction of sunlight because the longer slope allows for more sunlight to enter the structure. The longer side also faces south, thus maximizing heat from the sun’s rays.
- It can be costly compared to even span greenhouses.
- They require more support on the slanted roof.
- Uneven span greenhouses usually need a lot of maintenance on the roof after some time.
- Too much solar can penetrate to the greenhouse if the uneven-span greenhouse is located in areas close to the equator.
A-Frame Greenhouse Structure
The A-frame greenhouse style is one of the most common designs. The structure is simple to set and it is ideal for a small backyard garden. To form the A-frame, you would attach the roof and sidewalls of greenhouse together, which forms a triangular-like shape.
Most of A-framed greenhouses use translucent, poly-carbonate material, which helps to eliminate the cost from having to buy glass material. Most A-framed greenhouses are laid down in an open field or at the backyard facing the southern side.
|●||It maximizes on the use of space along the side walls.|
|●||Simple and straightforward to construct.|
|●||Conservative structure style, using minimal material.|
- It has poor air circulation at the corners of the triangle.
- Its narrow side walls limit the overall use of the greenhouse.
Quonset Greenhouse Structure/ Hoop-House Structure
The quonset design has a curved roof or arched rafters, and its design is similar to military-hut style. The circular band in the structure’s style is made of aluminum or PVC pipes, while the rooftop is made of plastic sheeting. The sidewalls of the design are set low, however, so there is not a whole lot of headroom. The hoops on the rooftop ensure there is no accumulation of snow and water on the top.
You would build this type of greenhouse in an open field or backyard with the structure facing the southern side.
|●||Easy to build and one of the cheapest designs due to the use of plastic sheeting.|
|●||Its design allows rain water and melted snow to run off.|
|●||Suitable for a small plant growing space.|
|●||Limited storage space.|
|●||Its frame design is not as sturdy as A-frame design.|
|●||As stated, there is less headroom in the structure.|
Gothic Arch Greenhouse Structure
Gothic arch has a nice aesthetic, and is one of the most visually pleasing designs available. The walls of the structure are bent over a frame, forming a pointed roof-like structure. The design requires less material to construct, as there is no need for trusses. Most of Gothic arch designs are made of plastic sheeting, and its design allows you to construct a large greenhouse where you can plant various products in rows.
|●||The design has minimum heat exposure, thus making it easy to conserve heat.|
|●||Plastic sheeting reduces the cost of construction.|
|●||It has a simple and efficient design that allows rainwater and snow to flow away.|
|●||Not enough headroom and the design has a low sidewall height, which limits the storage of the greenhouse design.|
Ridge and Furrow Greenhouse Structure
This type of design uses two or more A-framed design structures connected to one another along the roof eave length. The eaves offer more protection and act as a furrow to allow melted snow or rain water to flow away.
There are no side walls on the structure, which creates more ventilation in the greenhouse. It also reduces automation cost and fuel consumption, since only small wall area is exposed where the heat can escape.
Ridge and furrow greenhouse structure is ideal for growing vegetables, and they’re mostly used in Europe, Canada, the Netherlands, and Scandinavian countries.
|●||Ideal for large scale farming, and it’s easy to expand this type of greenhouse.|
|●||Provides more ventilation into the greenhouse.|
|●||Requires few materials for construction because of its lack of side walls.|
|●||Requires little energy to cool and heat.|
|●||Lack of proper water drainage system will damage your plants.|
|●||Although the design has no side walls, shadows from the gutters can prevent sunlight from entering the greenhouse.|
Sawtooth Greenhouse Structure
This type of greenhouse structure is similar to the ridge and furrow; however, sawtooth offers more natural ventilation. This is due to its natural ventilation flow path developed as a result of the sawtooth design. The roof provides 25% of the total ventilation to the greenhouse, and opening the sawtooth vents will ensure there is continuous airflow into the greenhouse. This makes it easy to control the temperatures and ensure the plants are in good climatic conditions for their growth.
|●||Sawtooth arches provide excellent light transmission into the greenhouse.|
|●||High rooftop allows for natural heat ventilation and airflow in the greenhouse.|
|●||Excellent structure for both warm and cold climatic conditions.|
|●||Simple and strong greenhouse structure.|
|●||Has a large farming area.|
Cold Frame Greenhouse Structure
Cold frame is ideal for greenhouse gardening in your backyard, and allows you to plant plants and vegetables at any time. It is one of the cheapest and simplest greenhouses you can set up. In cold frame gardening, you place a glass or plastic sheeting as the cover of the greenhouse structure, which will help in protecting your crops from frost, snow, rain, wind, or low temperatures.
Cold-frame greenhouse is suitable for planting cold-loving plants like broccoli, cauliflower, and cabbage among others.
Based on your budget, you can go for glass, polycarbonate, or plastic sheeting material to construct the greenhouse. The design requires a few openings to allow ventilation of heat into the greenhouse.
|●||Simple design and easy to manage.|
|●||Made from old windows or old wood pallets, which minimizes the cost of construction.|
|●||Overheating problem—a single day with a lot of sun and closed windows can do a lot of damage to the plants.|
|●||Recycling of the old materials can affect the material quality of the greenhouse.|
The hotbed structure acts as a miniature type of greenhouse that traps heat from solar radiation. This greenhouse can provide a favorable environment for plants that need a lot of heat like tomatoes, eggplants, and peppers.
If you want to extend the growing season, you can use hotbeds to provide the right weather conditions for your crops. Whether during winter, summer, or spring, there is always a family of vegetables, fruits, or herbs you can grow.
The hotbed structure provides a heat source to the crops through manure rather than using heat source from electricity, helping to speed up the growth of your plants.
When using a hotbed, you can set up the garden as wide as you want, provided the ratio of manure used and the growing medium is 3:1. The amount of time and money you invest in the garden will determine your farm produce success.
|●||Simple to design.|
|●||Hotbeds only lasts two months, so you will need to remove and replace the material with new ones around that time.|
A window farm is an indoor farming garden for most vegetables. In a window farm, plants rely on the natural light from the window and temperature control from your living area to grow. This method is ideal for those who don’t have a backyard or enough space to construct a standalone greenhouse.
You should set the structure in a window where it can receive a lot of light, facing toward the south.
|●||Amazing for growing vegetables.|
|●||Simple design and easy to construct.|
|●||Requires more components like nutrients, tubes, and pumps to grow your vegetables.|
|●||It is difficult to maintain compared to a normal, soil-based greenhouse.|
Construction of the Greenhouse
When building a greenhouse, you have to pay close attention to its base. Ensure you have a secure base and that it’s leveled up. Most structures have a metal base designed from a metal frame, which is separate from the rest of the structure.
You need to secure the base on the ground to avoid any movement. Make sure it’s strong enough to withstand heavy winds, as such an event could be disastrous.
Site planning for where to layout the greenhouse is important too, and you should also evaluate the soil. Depending on the soil underneath, you can prepare your soil structure and texture. For example, if the soil is light and sandy, you have to install concrete or use slabs in the area.