5 Best Polycarbonate Greenhouses Reviews of 2023 in the UK (2023)

If you have a countryside property with a vast piece of land or a private house with a larger garden and look for a reliable and roomy greenhouse to meet your horticultural needs on the all-year basis, the Palram Harmony will catch your fancy.

It is a spacious greenhouse that can be compared to a fully-fledged model. With 185 x 306 cm dimensions, this model provides 4.4 square metres of growing area. Meanwhile, the height of 208 cm will let you use the racks to place the boxes in several tiers to grow more crops and plants.

Moving on to the greenhouse design, the frame of the unit is made of strong corrosion-resistant aluminium and powder-coated for even better weather resistance. The transparent panels feature polycarbonate glazing that makes them damage- and shatter-proof. Although the whole construction weighs only 46 kg, it is highly durable and dependable. The load capacity this greenhouse is meant for is 275 kg/m² and thanks to a galvanised steel base, it can stand stable even against the blasts of wind up to 90 km/h. Hence, it will survive in harsh weather conditions. Yet, to further reinforce the whole structure and add more sturdiness, you can use anchors and stands that are sold separately.

The only issue that did disappoint us, though, is the time it takes to fully assemble the greenhouse. Despite a quite informative instruction manual, there is a great number of parts to put together that will take you about 5 hours. So, we recommend planning the installation in advance. On the bright side, however, the kit has pre-installed gutters to remove excess moisture and a roof vent for improved air circulation.

All in all, this large polycarbonate greenhouse from Palram will be a good pick for large garden owners that tend to grow vegetables, crops, and even flowers throughout the whole year. As functional, rugged, and reliable as it is, it will serve you for really long.

Growing some temperature-sensitive or exotic plants and consistent heat retention is a must when choosing a greenhouse? If so, then the Mythos model from Palram is for you.

At a glance, this greenhouse might seem a bit unusual due to its opaque look. Yet, it is what makes the Mythos special and sets it apart from the others. The thing is in polycarbonate glazing. In this model, the manufacturer applies the twin wall technology. It means two glazing sheets are moulded together with an air gap in between. Not only are such PC panels more durable but also they will better keep a stable ambient temperature for extended periods of time even during winter or in case of cold snaps. Besides, twin wall panels boast 100% UV resistance. They won't fade or change colour over time and prevent harmful UV rays from getting inside. At the same time, your plants will still get up to 70% of useful sunlight.

Owing to a sliding panel design, the whole greenhouse construction is a breeze to install. Just follow detailed instructions and you won't have any issues with the assembly. A rust-proof aluminium frame with a galvanised steel base makes up a strong and rugged framework that will keep the greenhouse securely in place and can withstand the wind load of 75 km/h or so. So, in case you are up for a serious storm, your Mythos greenhouse will handle it.

Roof venting and integral guttering will help create a maximum favourable atmosphere inside the greenhouse for raising the most demanding plants. However, the Palram Mythos has only one gutter, so, for better moisture control, we recommend using additional drainage pipes to avoid excessive humidity.

Wrapping things up, the Palram Mythos will be a good pick for farmers and amateur plant growers who need a relatively large growing area and seek to maintain a stable interior temperature without too many additional adjustments.

While cheap plastic greenhouses can only last for a while, full-size polycarbonate models are designed to withstand 5 or even more years of service. Fortunately, the Garden Grow D9399A is the model you can count on when it comes down to cultivating plants in your home garden. What makes it stand out are a thought-out design that will let you get the most out of greenhouse gardening and a fairly reasonable price tag that won't hit your budget.

At almost half the price of premium-class models, you'll get pretty much the same set of features. Thus, an aluminium frame with a heavy-duty galvanised steel base is there to provide good stability against the wind and weather elements. The kit also includes built-in side gutters for draining rainwater and controlling the air humidity inside and a manually operated window on the roof for appropriate ventilation and air circulation. The glass-free walls made of transparent polycarbonate perfectly trap the warmth inside the greenhouse. This is achieved, thanks to the twin-wall configuration of the housing normally found in more expensive models.

Another interesting aspect that can't be overlooked is the sliding door. Unlike hinged doors, the sliding door design is more convenient saving the space at the entrance and leaving more useful room inside the greenhouse. Besides, a sliding door won't be shut by the wind when you least expect it.

To conclude, the D9399A from Garden Grow is by far the best polycarbonate greenhouse in the medium price range that provides a safe and reliable space for growing plants in the comfort of your back yard.

If you are into growing flowers and other decorative plants in your garden and want to prolong the flourishing season for as long as it is possible, a polycarbonate greenhouse like the one from Outsunny will come to help.

The main advantage of any polycarbonate greenhouse over a glass model is a lightweight design that makes them easy to use and maintain. And this model surely is one of the easiest to assemble as compared to other models in the range. All frame elements are easily put together by self-tapping screws and PC sheets slide into the grooves in the frame. All hardware is included in the set and you'll just need a screwdriver.

The frame is made of light yet durable aluminium that won't rust or rot over time. Painted in green, the frame will easily blend with your garden natural landscape and perfectly fit into any decorative garden design pattern. Polycarbonate panels are almost transparent. Not only do they deliver enough sunshine to sun-loving plants but also they will let you view your flowers in all their beauty.

On the negative side, though, PC boards in this model are much thinner than in more sophisticated polycarbonate greenhouses. The panels are only 2mm thick against 4mm or even 6mm other models offer. Hence, the Outsunny is not the best option for all-year use. However, with a 43 km/h wind rate and UV30 sun protection, this greenhouse is a good choice for regions with a mild climate without harsh storms and winds where the temperature is relatively warm through the year. Otherwise, you'll have to get a greenhouse heater for the cold season.

All things considered, the greenhouse from Outsunny offers great value for the money and will be of great use in warmer regions where the temperature control is not that important and you rather need to create a consistent environment for growing some specific species or decorative plants.

This rather small greenhouse from Deuba features all you need to start a small garden in your back yard. With 190 x 195 x 195 cm dimensions, it won't take much garden space, yet, will still allow for placing a big number of plants, veggies, and even flowers. Thanks to the twin-wall polycarbonate panels, the heat won’t escape the greenhouse, thus easily providing the plants with much-needed warmth for long periods of time. In case you don’t need much heat inside, you can always use a special roof vent door to let the fresh and cool air in.

This kit also includes a sliding door, which provides maximum room for all the plants inside without taking any additional space. Moreover, the greenhouse comes equipped with water gutters to save your peace of mind about excessive humidity levels inside the growing area.

Furthermore, the all-weather aluminium frame of the greenhouse features anodised pieces that are exceptionally durable and have corrosion-resistant capabilities. In combination with a rugged steel base, the frame provides better construction strength and ensures a longer service life of the whole greenhouse.

As for the things we somewhat dislike in this model, the instruction manual contained in the set is not detailed enough. Hence, if you are a kind of entry-level gardener, it will take you quite a while to get the hang of the assembly.

All in all, the Deuba greenhouse will meet the needs of any casual gardener and make a perfect addition to any smaller garden or backyard limited in space.