Polytunnel vs Greenhouse

Are you looking to protect your home produce and extend your growing season but are uncertain whether to invest in a polytunnel or greenhouse?

Both types of structures are used for growing a wide variety of crops and flowers, protecting them from bad weather conditions and creating the optimal climate by retaining heat and moisture. People are often torn when deciding between the two, as both constructions serve the same purpose.

There are several factors that should be considered when deciding which structure is best for your garden.

How are garden tunnels different from greenhouses?

Both polytunnels and greenhouses have one fundamental thing in common. They both help to create the best possible growing conditions for your plants but they do this in different ways.

Polytunnels are typically made from steel and covered in polythene (plastic) as opposed to greenhouses which are made out of glass and have an aluminum or metal frame. The polyethylene material has 88% light transmission which means it generally performs better than glass which has a light transmission of 65% to 85% depending on the pane size and glasshouse structure.

Glass greenhouses create a very hot climate for your crops but cant diffuse the light that well, which results in hot spots. Haygrove Garden Tunnels on the other hand use a polythene cover that has an additive that diffuses or scatters the light when it enters the polytunnel. This means that the light is more available and gets deeper into the canopy of the plants. Also, there is less direct radiation and a higher risk of scorching on the upper leaves of the plant.

Greenhouses are thought to be more aesthetically pleasing, coming in many different shapes and styles such as Victorian or Orangeries. However, polytunnels are a far more practical option and are considerably more budget-friendly at only a third of the cost of a greenhouse, polytunnels are excellent value for money.

Polytunnels tend to be used more in community gardens and allotments as they are cheaper, more practical, and easily moveable. However, recently more domestic gardeners have been realising the benefits and purchasing one for their homes.

Polytunnel features

Haygrove Garden Tunnels only use the highest quality materials making them heavy-duty polytunnels. The 2m side height ensures you are maximising the growing space inside your polytunnel.
Every Haygrove Garden Tunnel is fitted with a manual roll-up, roll-down ventilation system. The vents are covered by an insect net to let air in, but keep the pests out!
The grade of steel is specified as E320. This is the structural grade of steel used in building and construction and not the mild steel grades that are often used in cheaper products that end up not performing well in heavy winds. Galvanisation is to the British Standard of 275g/m2.
Polytunnels are usually built straight onto a soil base, with the only site preparation require being a simple site clearance. They’re also easier to dismantle, move, and reassemble.

Greenhouse features

The walls and roof of a greenhouse comprise glass so that the plants are exposed to natural light for much of the day.
Greenhouses offer great light transmission, but they are vulnerable to overheating and causing sun damage which is why plants need more shading.
There are several ways to tackle this issue – some people paint some of the glass or fit external blinds to reduce the quantity of light coming through. You can also add vents, roll-up sides, and heaters can all be installed to help control the climate.

The benefits of Garden tunnels

It is generally thought that polytunnels retain more heat than greenhouses, and so extend the growing season much longer. One of the most important advantages of a polytunnel is its air circulation. Large doors at both ends provide sufficient airflow through the tunnel, and Haygrove Garden tunnels also have full-length side lengths to allow for optimal ventilation during the summer. Polytunnels tend to be a lot larger, and therefore allow for more growing space. The A-frame shape of the Haygrove Garden Tunnel gives a side height of over 2m (6″6″) even to the edge of the polytunnel, which gives you the option of growing tall plants too.

There are some misconceptions about the sturdiness of garden polytunnels. Using our experience of over 30 years in polytunnels, our engineers have designed a superbly strong structure using grade materials. All the steel is galvanised and the polythene cover is a unique woven material. Haygrove Garden Tunnels are built for the long term! Take a look at our virtual tour to see how strong they really are.

In each 2m section, there are 4 steel anchors that are driven at a 45° angle into the ground. Each anchor is 0.8m (2’6″) long and is made out of a 3mm galvanised reinforced steel bar. Polytunnels can also be erected on a slightly uneven surface, so are perfect for gardens with unequal terrain. P

Important factors to think about when purchasing a Garden Tunnel

The lifespan of both polytunnels and greenhouses are relatively similar, although the covers of polytunnels will need replacing every 5-10 years to maintain their efficiency. While both can be moved, polytunnels can be taken apart and reassembled with far greater ease – the glass panels of a greenhouse are at high risk of damage and can be far more expensive to replace.
Haygrove Garden Tunnels are available in two widths, 3m (9’8″) and 4m (13’1″). The lengths available range from 6m (19’6″), and then increase in 2m increments, up to a maximum length of 20m (65’6″).
Before purchasing a polytunnel you should consider how much space you have and how much space you will need. We always recommend getting the maximum size for your garden, because more often than not, customers wish they had purchased a tunnel with more space.
Garden Tunnels are much more forgiving than a glasshouse and can be safely positioned on gently sloping land. There is no need for the ground to be leveled or paved first. The only important point is that if the ground has a slop it must be a consistent slop and not undulating.

Although there are benefits to greenhouses, polytunnels offer great options for year-round growing as well as being budget-friendly. Haygrove provides small polytunnels and large polytunnels alongside replacement polytunnel covers and other polytunnel accessories – something suitable for everyone. If you would like further advice and support when it comes to purchasing a Garden Tunnel then speak to one of our experts here.