Best greenhouses & cold frames for UK gardens (2026)
A greenhouse is what turns a short British summer into a proper growing season: you start seedlings weeks earlier, ripen tomatoes, peppers and chillies that would sulk outdoors, and keep hardy crops going through winter. Here's how the options compare — from a full walk-in greenhouse to a cold frame that does most of it for a fraction of the price.
By Tom Calder · Updated 4 November 2026 · 4 products, all price-tracked
Our picks
Photo: AmazonPalram Canopia Harmony 6x4
First-time growers wanting a low-maintenance, shatter-safe greenhouse for a small garden or patio.
as of 4 Nov 2026, 19:07 GMT · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.
Photo: AmazonPalram Canopia Mythos 6x8
Households wanting a durable, unheated space to grow their own food and start seedlings year-round.
as of 4 Nov 2026, 19:07 GMT · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.
Photo: AmazonOutsunny 4-Tier Mini Greenhouse (Clear PVC Cover)
Hardening off seedlings and giving young plants frost protection on a patio or balcony, on a tight budget.
as of 4 Nov 2026, 19:07 GMT · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.All 4 compared
| Greenhouse | Type | Size | Glazing | Price |
|---|---|---|---|---|
Polycarbonate greenhouse, aluminium frame · 6ft x 4ft (1.85m x 1.26m footprint, 2.08m ridge) · 0.7mm clear polycarbonate (90% light transmission) First-time growers wanting a low-maintenance, shatter-safe greenhouse for a small garden or patio. | Polycarbonate greenhouse, aluminium frame | 6ft x 4ft (1.85m x 1.26m footprint, 2.08m ridge) | 0.7mm clear polycarbonate (90% light transmission) | £329 at Amazon as of 4 Nov 2026, 19:07 GMT · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched A sensible entry-level greenhouse: the polycarbonate panels are safer and warmer than glass, and the slide-in assembly is genuinely manageable for one or two people. Fine for seedlings and salad crops, provided you anchor it to a solid base. Best for First-time growers wanting a low-maintenance, shatter-safe greenhouse for a small garden or patio. Good
Worth knowing
Who shouldn't buy it: Don't buy it if you are in an exposed or coastal spot and can't bolt it down to a firm base. The thin polycarbonate panels are prone to blowing out in gales, so a heavier toughened-glass or twin-wall greenhouse is the safer long-term buy. Read the full review → | ||||
Walk-in hobby greenhouse (aluminium frame, polycarbonate) · 6 x 8 ft (approx. 1.85 x 2.5 m) · 4mm twin-wall diffused polycarbonate (82% light transmission) Households wanting a durable, unheated space to grow their own food and start seedlings year-round. | Walk-in hobby greenhouse (aluminium frame, polycarbonate) | 6 x 8 ft (approx. 1.85 x 2.5 m) | 4mm twin-wall diffused polycarbonate (82% light transmission) | £449.31 at Amazon as of 4 Nov 2026, 19:07 GMT · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched A sturdy, sensibly priced walk-in greenhouse whose twin-wall polycarbonate is far more forgiving than glass around children, pets and stray footballs. A solid, low-drama choice for growing more of your own food, provided you anchor it properly to a firm base. Best for Households wanting a durable, unheated space to grow their own food and start seedlings year-round. Good
Worth knowing
Who shouldn't buy it: Your plot is very exposed or you can't fix it to a solid, level base — owners repeatedly report panels dislodging in gales, so a sheltered, firmly anchored spot is essential. Read the full review → | ||||
Portable 4-tier grow-house, steel frame with four steel shelves · 160 x 70 x 50 cm (H x L x W) · Clear PVC cover with roll-up zipped door Hardening off seedlings and giving young plants frost protection on a patio or balcony, on a tight budget. | Portable 4-tier grow-house, steel frame with four steel shelves | 160 x 70 x 50 cm (H x L x W) | Clear PVC cover with roll-up zipped door | £23.99 at Amazon as of 4 Nov 2026, 19:07 GMT · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched A cheap, compact way to shelter seedlings through spring frosts, and easy to put up without tools. Treat it as a season-or-two consumable rather than a lasting greenhouse, and anchor it well. Best for Hardening off seedlings and giving young plants frost protection on a patio or balcony, on a tight budget. Good
Worth knowing
Who shouldn't buy it: Your growing spot is exposed or windy, or you want something that lasts several years, in which case a rigid polycarbonate cold frame or greenhouse is a better use of money. | ||||
 Walk-in growhouse (soft-cover greenhouse) · 195 x 143 x 143 cm, 3-tier with 8 shelves · Removable waterproof PE cover Cheaply extending the growing season or hardening off seedlings on a patio or allotment. | Walk-in growhouse (soft-cover greenhouse) | 195 x 143 x 143 cm, 3-tier with 8 shelves | Removable waterproof PE cover | £40.99 at Amazon as of 4 Nov 2026, 19:07 GMT · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched A budget-friendly, quick-to-assemble walk-in cover that does a genuine job protecting seedlings and tender plants through the shoulder seasons. Treat it as a two-or-three-season consumable rather than a permanent structure. Best for Cheaply extending the growing season or hardening off seedlings on a patio or allotment. Good
Worth knowing
Who shouldn't buy it: Your plot is exposed or windy, or you want a permanent year-round greenhouse — spend more on a rigid glass or polycarbonate structure that will actually last. | ||||
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Before you buy
Choose glazing first.
Toughened glass looks best, lasts longest and lets in the most light, but it's heavier, pricier and breaks. Twin-wall polycarbonate is lighter, much harder to break (safer around children), and insulates better, though it lets through slightly less light and can discolour over many years. For most home growers, polycarbonate is the sensible, safe choice.
Size up — everyone wishes they'd bought bigger.
A 6×4 is the popular starter size, but staging and grow bags fill it fast; a 6×8 gives room to actually work. Aluminium frames are maintenance-free and the norm; wooden frames look beautiful but need upkeep. Whatever the size, you need a firm, level base — paving slabs or a proper base kit — and it should be anchored, as greenhouses catch the wind.
Consider the cheaper alternatives honestly.
A cold frame (a low, lidded box) is brilliant for hardening off seedlings and growing low salads; a walk-in plastic 'growhouse' shelters tomatoes and peppers for very little money, though the covers perish after a few seasons. These are where many growers should start. Add ventilation (an auto vent opener is worth it) whatever you buy — a closed greenhouse cooks plants on a hot day.
We verify every product's specifications against at least two independent sources, re-check its UK price and stock on a schedule where we can track it automatically, and cross-check safety-relevant claims against official guidance. Every review is labelled Researched or Used and reviewed by us: where we've bought a product, or been sent it free, and used it ourselves, its review says which; where we haven't, our verdict is a considered spec-and-evidence comparison, not a hands-on test. When two products are close, commission can decide which one we pick. A clearly better product always wins. Read our full methodology →
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Common questions
Glass or polycarbonate greenhouse — which is better?
Glass lets in the most light and lasts longest but is heavy, pricier and breakable. Twin-wall polycarbonate is lighter, much safer (won't shatter), and insulates better, at a slight cost to light. For most home growers, especially with children or pets, polycarbonate wins.
What size greenhouse should I get?
6×4 is the popular starter size but fills up fast; 6×8 gives room to work. Almost everyone wishes they'd gone bigger, so size up if space allows — and make sure you have a firm, level, anchored base.
Do I need a greenhouse or is a cold frame enough?
A cold frame or mini growhouse does much of the useful job — hardening off seedlings, protecting young plants, extending the season — for a fraction of the cost. A full greenhouse is worth it for serious year-round growing and ripening tender crops.
Where should I put a greenhouse?
A sunny, sheltered, level spot away from overhanging trees, ideally running roughly east–west for even light. It needs a firm base (slabs or a base kit) and must be anchored, since greenhouses catch the wind.
Do greenhouses need ventilation?
Yes — a closed greenhouse can overheat and cook plants on a warm day. Roof and side vents, and ideally an automatic vent opener, are essential; add shade netting for high summer.
Can I grow in a greenhouse over winter?
You can grow hardy salads, overwinter plants and start early crops, but most greenhouses are unheated, so they protect from frost only a little. A cold frame inside, fleece, or a small heater extends what's possible.
