When deciding between a greenhouse or a polytunnel, the key is to think long term. While the initial cost is a factor, it’s only part of the equation. Your decision will significantly impact the health of your plants and the overall return on investment.
Instead of viewing this as just a purchase, consider it a financial investment. Let’s break down the factors that matter most.
How Long Will It Last?
The first consideration should be longevity and cost-effectiveness. Is it worth saving a little upfront, or should you stretch your budget for a solution that offers better long-term value? Many gardeners regret buying the cheapest option, realising later that a more informed decision would have saved money and effort over time.
At the heart of this issue is the cladding, the material that shields your structure from harsh weather and provides the ideal growing conditions for plants.
Here are the three main types of cladding:
Polythene Sheeting (the most affordable option)
Glass (a step up in cost)
Technically Advanced Cellular Cladding (a modern, premium option)
The Role of Cladding in Plant Health
The price difference between cladding materials comes down to performance. For plant health, technically advanced cellular cladding stands out as the best option.
Polythene Sheeting - Often needs to be replaced every 5 years, depending on quality, and is prone to tearing during strong winds or heavy snow.
Glass - Prone to breakage and requires additional measures like blinds or whitewashing to prevent plant burn.
Technically Advanced Cellular Cladding - Scientifically proven to create the most plant-friendly environment, eliminating the need for additional shading or augmentation. It can also withstand wind speeds of 120 mph and heavy snow loads without damage.
Structural Support Matters
The strength of the supporting frame is equally important. A robust frame ensures durability and long-term performance. Common materials include:
Wood - Traditional but requires constant maintenance like painting or oiling.
Aluminium and Galvanised Steel - Durable but not as strong as high-tensile steel.
High-Tensile Galvanised Steel - Offers superior strength, making it the ideal choice for supporting advanced cladding.
Managing Internal Temperature
Maintaining the right temperature is critical for plant health.
Cooling - Simple measures like opening vents and doors usually suffice for all types of structures.
Heating - This is where the type of cladding makes a significant difference.
Polythene and glass-clad structures often require heating during colder months because they lack heat retention. In contrast, greenhouses with technically advanced cellular cladding retain heat so effectively that heating may not even be necessary, even in extreme climates like the Shetlands or Falkland Islands. This results in substantial cost savings over time.
Protection Against Excess Sunlight
Polytunnels and glass-clad greenhouses are vulnerable to plant burn on sunny days, often requiring expensive blinds or labour-intensive whitewashing. With technically advanced cellular cladding, this problem is eliminated, as its construction naturally regulates sunlight, providing consistent and safe light levels for plants.
The Decision Is Yours
The time to decide is now. Once you make a purchase, there’s no turning back. By understanding the technical aspects outlined above, you can make an informed choice that fits your long-term goals.
When consulting manufacturers, ask about their guarantees. Some may offer vague answers like "it depends," while others provide clear terms. Ultimately, the question is this:
Do you want to buy a short-term solution, or do you want to make a long-term investment for peace of mind?
The choice is yours. Choose wisely.
Comments