Best greenhouse: Our favourite greenhouses to help your plants flourish
Grow champion crops or brighter blooms in our pick of the best greenhouses large and small
Having a great greenhouse is essential for any gardener. Within its transparent walls, the elevated temperature and shelter from the weather means any number of exotic or out-of-season plants can be grown either for planting out later, or to spend their entire lives inside.
Whether it’s for sowing seeds in the early spring or overwintering tender plants that otherwise wouldn’t survive, one of the most common uses for a greenhouse is as a large, human-accessible cold-frame. There’s more to one than that, however. A greenhouse that’s large enough, and equipped with a platform at the right height, makes for a wonderful workspace that allows you to carry on gardening whatever the weather. And whether you’re growing tomatoes, melons, cucumbers, chillies or something far more obscure, the addition of a greenhouse to your garden or allotment will improve not just your ability to grow plants, but the enjoyment you get from them, too. You might even become the envy of your neighbours.
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Best greenhouse: At a glance
How to choose the best greenhouse for you
Not all the best greenhouses are created equal. Not only are there several different types, but both the panels and frame can be made from a variety of materials. There are many different sizes, from those you can barely turn around in to those a family of five could happily live in, and there are all sorts of other considerations, such as doors, ventilation and built-in staging.
However, unless you’re lucky enough to get one for free from a neighbour or fellow allotmenteer (it does happen), a greenhouse is a major expense. The frames may be wooden or lightweight aluminium, but all that glass can be expensive and is heavy to ship. Shatterproof polycarbonate panels are beginning to dominate the market (avoid the double-walled ones that are like corrugated cardboard and go for the smooth sheets of glass-like plastic a few millimetres thick) but the extra weight provided by the more traditional material can actually help protect the structure. The greenhouse’s number one enemy is a child with a football, but a close second is the wind. Siting your greenhouse properly is therefore essential, as the wind will find its way in through any gap and either try to turn the whole thing upside down, or simply blow it apart from the inside.
To avoid this, try to place your greenhouse somewhere sheltered, not right next to open farmland. A fence or wall will give it some defence against the wind and stop heat escaping from every surface, too. Your greenhouse will also need a base, which can be either a custom-built frame or something like railway sleepers or stone blocks to which it can be securely bolted.
The most popular types of greenhouse
Free-standing: Probably the first thing you think of when you think “greenhouse”. These generally have straight sides and a pitched roof, with a sliding door and at least one window that opens. They are 100% glass or plastic apart from a thin frame, which increases their heat-retaining properties during the day, but also means they will radiate that heat back out again at night. Everything is out to get the freestanding greenhouse, and it can be fragile, so position it where the minimum of harm can come to it.
Aluminium-framed: The cheapest option for a free-standing greenhouse, aluminium frames are stiff but light. Beware of extremely cheap ones, which can be made from a floppy alloy that doesn’t maintain its shape, even when bolted together, and will almost certainly lead to a heartbreaking experience when you start adding the panels. A greenhouse made of aluminium and plastic panels will be too light to maintain much wind resistance, so while it’s possible to economise, beware the dangers of completely cheaping out.
Wooden-framed: By contrast, a wood-framed greenhouse can be both stronger and heavier than its aluminum brethren, at the cost of the frame being much thicker, thus providing more shade. They often have low wooden walls with glass on top, increasing football resistance. They are afflicted by the usual wood-related problems, so need to be treated against damp and insects. Wood is also much more flammable than aluminium, so take that into account if you want to heat your greenhouse with gas, paraffin or anything else that can go boom in the night. Wooden frames are more pleasing to the eye than aluminium, so if your greenhouse is visible, it makes a good choice.
Lean to: By placing three sides of a greenhouse up against an existing wall, you not only increase the structural integrity and provide some shelter from the wind, but also give it an element of heat storage, as the bricks, warmed by the sun, will soak up heat and radiate it out for longer at night. As you’re only buying three sides, lean-tos can be cheaper than a free-standing model, but you might need some DIY know-how to securely attach it to a wall. And of course, the wall won’t let any light through.
Mini: Popular in urban spaces, patios and allotments, a mini greenhouse is even lighter than a free-standing one, and those with push-together frames and zip-up plastic covers are particularly susceptible to being torn apart by the wind and deposited over neighbouring gardens. Get it right, though, perhaps in a sheltered corner with some bricks in the bottom, and it can provide a valuable green oasis in an area that’s otherwise suboptimal for gardening.
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The best greenhouses to buy
1. BillyOh 4000 Lincoln Wooden Clear Wall Greenhouse with Opening Roof Vent, 9×6 ft: Best wooden greenhouse
Price: £879 | Buy now from Garden Buildings Direct
Garden Buildings Direct’s BillyOh 4000 range of wooden greenhouses contains structures of multiple sizes, materials and features, but to our eye this is the best of the bunch. The doors open wide, the frame looks great, and the polycarbonate panels are clear, strong and as close to glass as you’re going to get without melting sand.
The opening roof vent allows you to regulate the temperature, and the pressure-treated (optional) European-sourced timber comes as pre-assembled panels for easy construction. There are all the options you could need, including bases, gutters and internal shelving. And the prices aren’t completely eye-watering, either, with the 9 x 6ft model coming in at well under £1,000.
Key specs – Dimensions: 9x6ft; Frame: Timber; Panels: Styrene/polycarbonate
2. Palram Canopia Harmony Polycarbonate 6x6ft: Best budget buy
Price: £350 | Buy now from Shedstore
An aluminium frame and plastic panels are allyou need to get the benefits of a greenhouse for the smallest possible outlay. The choice of materials keeps it light too, so it will be easy to manoeuvre and erect.
You get a lot for your money here, as alongside the galvanised steel base there’s a lockable door (padlock not included), integrated gutters (just right for a water butt feed) and an opening roof vent. The 6x6ft dimensions are nice to see too, as many greenhouses at this price point only manage 6x5ft, which is just too tight a squeeze for many gardeners and their plants.
The clear polycarbonate, which allows 90% light transmission and won’t discolour, is extremely thin, but the manufacturer claims it’s wind resistant to over 50mph and can take 70kg of snow per square metre too. Add this to the five-year guarantee, the rust-proof nature of the aluminium frame, the number of add-ons available (including staging, an irrigation kit, and a heater) and the attractive price, and you’ve got a solid budget build.
Key specs – Dimensions: 6x6ft; Frame: Aluminium; Panels: 0.7mm polycarbonate
3. Ida 7800 Lean-To Greenhouse Glass Glazing: Best lean-to greenhouse
Price: £859 | Buy now from Primrose
An advantage of lean-to greenhouses is that they can be bigger than free-standing designs while giving up nothing in terms of stiffness, as the brick wall running the whole length gives them all the support they need. Twelve feet is enough room for a lot of plants, or even a table and chairs, and the 7ft 3in maximum height means even the tallest gardener will be able to stand up inside.
A steel base is an optional extra, but this greenhouse contains a large amount of glass and, when attached securely to a wall, should hold its own against the wind. The double doors slide back from the centre of the longest side, and there are two opening roof windows to aid ventilation and stop things from getting too hot in summer.
Key specs – Dimensions: 6x12ft; Frame: Aluminium; Panels: Glass
4. Halls Silver Aluminium Popular (6x8ft): Best greenhouse for day-to-day use
Price: £942 with polycarbonate upgrade and steel base | Buy now from South West Greenhouses
Halls’ greenhouses come with a plethora of optional upgrades, and we’ve added a steel base and 4mm polycarbonate glazing to the base price of £627 to get to the price above. These are worthwhile upgrades, and you may find the addition of two-tier staging, rainwater collection kits (guttering is guilt in), and an irrigation system useful too.
While it is available in 6x4ft and 6x6ft sizes, the extra room a 6x8ft greenhouse gives for both plants and moving about makes a big difference. Being able to put plants or staging along three sides and still be able to turn around in your greenhouse is hugely important to its usability.
Otherwise, this is a traditional apex-roofed greenhouse with an aluminium frame and one roof vent. It’s very traditional, in a style that has lasted because it’s convenient both for working – the ridge height keeps you in the middle and your plants at the edges – and for shedding rain or snow. It’s a sturdy, practical design that will look good in a garden or allotment, and with the steel base and polycarbonate upgrades should stand up to the weather too.
Key specs – Dimensions: 6x8ft; Frame: Aluminium; Panels: 4mm polycarbonate
5. Forest Cofton Wooden Small Wall Lean To Mini Greenhouse
Price: £640 | Buy now from Buy Sheds Direct
It’s not something you’re going to be able to shelter from the rain in, but this mini lean-to greenhouse would make a great addition to a small garden or courtyard. That said, it is expensive for what you get, and it really isn’t very big at all.
At least the construction is solid, with a pressure-treated tongue-and-groove wooden frame allowing multiple attachment points for the adjustable shelves, which is perfect for when you want to grow taller plants. You get two vents for air circulation, and despite being described as a lean-to it comes with a back wall. That means you don’t need to worry too much about attaching it to a flat surface, and it can be placed anywhere that it won’t fall over.
Small greenhouses like this are often perfect for allotments, where they can be attached to the side of a shed to provide enough covered space to grow on vegetable seedlings or germinate those plants that can’t be directly sown outside.
Key specs – Dimensions: 4ft 10in x 2ft 5in; Frame: Wood; Panels: Styrene
