Polythene vs Polycarbonate Greenhouses: What’s Right for Your Garden?
June 26, 2025
When you’re starting a garden, choosing the right greenhouse can feel like a big decision. It’s not just about size or shape. The material makes a huge difference to how your plants grow, how long your structure lasts, and how much ongoing effort it takes to maintain. At Morrifield, we often get asked about whether polythene or polycarbonate greenhouses are a better option. The answer? It depends on your goals. Both materials offer great advantages, and the best fit comes down to how you plan to garden, your space, and your long-term plans and your budget.
Let’s take a closer look at how each material compares, especially for gardeners across New Zealand looking to set up a reliable structure that can handle our changing weather.
What is a Polythene Greenhouse?
Morrifield polythene greenhouses use a commercial-grade greenhouse fabricated cover that is stretched over a strong anodised aluminium frame. This style has been used for decades by growers large and small. They’re cost-effective, easy to set up, and work well for many gardening applications.
Why choose polythene?
- Lower upfront cost makes them more affordable
- Easy to install, even for first-timers
- Excellent light transmission for growing plants
- UV 4 year cover warranty with expected lifespan of 7-10 years
- Hail, snow and strong wind resistant
- Preferable to have some wind protection from prevailing wind
- Prefabricated cover for easy installation
Polythene greenhouses are especially popular with new gardeners, those working within a budget, or anyone looking to add a greenhouse to their garden space. They’re a great choice for extending your growing season and promoting faster growth.
Considerations:
While polythene greenhouses are a durable option, the film cover will need to be replaced after several years (typically 7–10). Some gardeners don’t mind this, especially given the lower initial investment.
That said, polythene greenhouses continue to be our biggest seller and are a reliable and widely used option for backyard growers, hobbyists, and even small-scale commercial growers.
What is a Polycarbonate Greenhouse?
A polycarbonate greenhouse is made with 6mm acrylic coated polycarbonate panels instead of traditional glass or plastic film. The panels are twin walled and are known for their strength, insulation, and resistance to weather. We use polycarbonate in our Morrifield greenhouses because it creates a stable growing environment, making it easier to garden all year round in New Zealand.
Why choose polycarbonate?
- Polycarbonate is long-lasting, as twin wall polycarbonate can last 15 to 20 years with minimal maintenance.
- The sheeting has a 15 year UV warranty
- Better insulation helps to maintain a more stable growing environment, especially in cooler regions
- Impact resistant and holds up well against hail, wind, and UV exposure
- Diffused light reduces the risk of scorching and helps plants grow evenly meaning there is less need for shade covers
- Improved appearance that looks more permanent and blends into the garden better
- Curved sheeting which gives maximum strength
- Partially assembled for easier installation
Considerations:
While polycarbonate greenhouses do cost more initially, the difference is not as big as many people think. When you factor in the longevity of the product, it is more appealing to some customers. Polycarbonate lasts longer, and saves time on replacement costs further down the track.
Which Greenhouse is Right for You?
The choice between polythene and polycarbonate greenhouses isn’t about which one is better – it’s about which one fits your needs.
If you’re looking for an affordable, flexible solution that gets you growing quickly, polythene is a fantastic option. It’s ideal for seasonal growers or those with limited space or budgets.
If you want a long-term structure with strong insulation, great weather resistance, and minimal maintenance, polycarbonate might be the better investment, especially if you plan to grow year-round.
Not Sure What Greenhouse to Choose?
If you’re still deciding between a polythene or polycarbonate greenhouse, take a look at Morrifield Greenhouses’ range to explore options built for New Zealand conditions. We have put a lot of thought into making our greenhouses practical, long-lasting, and fit for purpose.
You can also head to our New Zealand greenhouses page to learn more about the different styles and sizes available.
We are always happy to help if you have questions, whether you are starting small or planning a full backyard setup. The right greenhouse should make gardening simpler, not harder. Get in touch with us to learn more about our range of greenhouses and find the right fit for you.