Best cold frame UK
Updated: October 2026
You want a best cold frame UK shortlist that stays inside one amazon.co.uk capture, not a magazine list of glass frames you cannot buy on these pages. Six timber kits were on the shelf on 20 October 2026, from £46.99 to £129.99. Peter F. scored amazon.co.uk stars and review counts, how well each shape suits hardening off and venting, and price. There was no lab test. A qualifying purchase can earn a commission at no extra cost to you. The full table is the [cold frame comparison](/hub/raised-beds-greenhouses-and-compost/cold-frame).
You want a best cold frame UK shortlist that stays inside one amazon.co.uk capture, not a magazine list of glass frames you cannot buy on these pages.
You want a best cold frame UK shortlist that stays inside one amazon.co.uk capture, not a magazine list of glass frames you cannot buy on these pages. Six timber kits were on the shelf on 20 October 2026, from £46.99 to £129.99. Peter F. scored amazon.co.uk stars and review counts, how well each shape suits hardening off and venting, and price. There was no lab test. A qualifying purchase can earn a commission at no extra cost to you. The full table is the cold frame comparison.
Our top picks
| Badge | Product | Form | Footprint | Glazing | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Outsunny Outsunny fir cold frame | Low single lid | 100 × 65 cm | Polycarbonate | 8.6 | about £46.99 | View offer |
 Spear & Jackson Spear & Jackson cold frame | Low single lid | Two size lines | Plastic panes | 8.0 | about £68.94 | View offer | |
| Best value |  Outsunny Outsunny twin-lid cold frame | Low twin lid | 100 × 50 cm | Polycarbonate | 8.0 | about £47.59 | View offer |
On this page
Top pick: the low Outsunny at £46.99
The top pick is the Outsunny wooden cold frame, model 845-471, ASIN B08TGJ9YWH. On amazon.co.uk it is £46.99 with 4.3 from 271 reviews, and the title and technical rows both say 100 × 65 × 40 cm. The cover is polycarbonate, the frame is fir, and the pack weighs 4.4 kg, with one top opening. That is the strongest review line in the set, which is why it takes the top pick. The wood wants a coat before winter, and some buyers report transit damage. The RHS puts a typical cold frame depth around 45–60 cm, so this lid is slightly squat for tall pots.
Best value: the twin-lid Outsunny at £47.59
The best value is the Outsunny with two top covers, model 845-538ND, ASIN B09P667654, at £47.59 with 4.0 from 121 reviews. Title and item rows agree on 100 × 50 × 36 cm. Fir and polycarbonate again, two vents listed, and a heavier 8 kg pack. The price sits within a pound of the top pick, and the second lid is the reason to choose it: you can vent one half and leave the other closed. It does not earn the top pick, because 4.0 from 121 is a thinner line than 4.3 from 271. At 36 cm it is a low box, not a place for large shrubs in pots.
When the Spear & Jackson is the one to buy
The Spear & Jackson COLDFRAME1, ASIN B004NCY5K2, is £68.94 with 4.0 from 172 reviews. Buy it only if you have read both size lines: 90 × 45 × 46 cm on the technical row, and 1000 × 660 × 400 mm in a title bullet. The cover row says plastic panes and the frame row says plastic, while the marketing talks about timber. UK reviews praise one-person assembly, then describe soft wood that needs treatment each year, stiff lid props mounted on the outside, and blistered paint on those props. Against the £46.99 Outsunny you are paying about £22 more for the brand and taking a size conflict with you.
Tall cabinet: SG Traders, and who should leave it
The SG Traders wooden greenhouse, ASIN B096YK3CJ3, is £79.99 with 4.2 from 220 reviews. The technical row is 69 × 49 × 120 cm, with polycarbonate panels, two doors, four vents, and removable shelves named in the title. Choose it when you want standing access and shelves. Leave it when you wanted a lid over trays on the ground. The repeated criticism is opaque panels. The feel good planter-style frame at £129.99 stays off this shortlist: the title size is not backed by an item-dimensions row and the cover row says PVC. The Outsunny three-tier at £56.99, 3.2 from 201 reviews, is the listing to skip when doors must meet. The shape split is set out in cold frame vs mini greenhouse.
Common questions
Which cold frame is the top pick in this set?
The top pick is the Outsunny 845-471 at £46.99, with 4.3 from 271 amazon.co.uk reviews and an agreed size of 100 × 65 × 40 cm. It is a low fir and polycarbonate lid for trays on a patio, not a tall shelved house. It leads this capture on review evidence. It does not lead every cold frame sold in the UK.
Which listing is the best value?
The best value is the twin-lid Outsunny 845-538ND at £47.59, with 4.0 from 121 reviews and a size of 100 × 50 × 36 cm. You are paying almost the same as the top pick and gaining a second lid for staged venting, with a weaker review line and a narrower box. Buy it for the two covers, not because it has the most stars.
Is the Spear & Jackson worth more than the Outsunny?
Only if the brand and the single lid are what you want after you accept two size lines. It is £68.94 with 4.0 from 172 reviews, about £22 above the 4.3-star Outsunny at £46.99. Assembly is a common praise. Soft wood, stiff outside props and blistered paint are the common complaints. The millimetre bullet and the 90 × 45 × 46 cm row do not describe one footprint.
Why do doors not close on some Outsunny kits?
That complaint belongs to the three-tier Outsunny, model UK845-0440331, at £56.99 with 3.2 from 201 reviews, not to the low single-lid top pick. UK reviews of the three-tier repeat doors that do not meet, warped boards and fiddly assembly. The low 100 × 65 cm frame is a lid, not a pair of cabinet doors. If a flush door is the point of the purchase, this three-tier is the row to avoid.
Will polycarbonate protect plants from frost?
No listing here states a frost temperature, and we do not claim one. The RHS says a cold frame gives more frost shelter than a cloche when you use it properly, and it still will not hold a hard frost without extra insulation and sensible venting. These six kits are unheated plastic-glazed boxes. Fleece and planting dates still matter on a severe night.
What size cold frame suits two seed trays?
The 100 × 65 × 40 cm Outsunny is the top-pick footprint we would put two trays in, as a rule of thumb. The twin-lid model is 100 cm long but only 50 cm wide, so the second tray is a tighter fit. The RHS typical depth of about 45–60 cm means both of these lids are a little low. The Spear & Jackson size is not settled enough to plan trays against until you decide which printed line you trust.
Related pages
Sources
Public UK sources from the research digest, last checked on 20 October 2026. Amazon.co.uk listing lines are the price and review source for the six ASINs. No frost or assembly test was run.
- RHS — Coldframes and mini-greenhouses (retrieved 20.10.2026)
- RHS — Choosing greenhouses (retrieved 20.10.2026)
- RHS — Hardening off tender plants (retrieved 20.10.2026)
- RHS — Cloches (retrieved 20.10.2026)
- RHS — Frost damage prevention (retrieved 20.10.2026)
- Gardeners' World — Best cold frames 2025 (retrieved 20.10.2026)
- Consumer Rights Act 2015, section 22 (retrieved 20.10.2026)
- GOV.UK — Returns and refunds (retrieved 20.10.2026)