About Our Cold Frames
We stock 33 in-stock cold frames and growhouses, from £249 for an Elite Min E Lite up to larger Access coldframes. A cold frame is a low, lidded box that traps warmth near the soil. We use them to harden off seedlings raised indoors before they face open ground. They also stretch the growing season at both ends, sheltering early sowings in spring and tender crops in autumn.
Lids come glazed in toughened glass or twin-wall polycarbonate. Glass holds heat and lasts for years. Polycarbonate is lighter and shrugs off knocks. Most frames sit at low level, though the Palram Plant Inn raises the bed to a comfortable height. For taller protection look at our mini greenhouses or small greenhouses. Pair any frame with our greenhouse accessories for staging and shelving.
Why We Chose This Range
"I tested a 6x4 Access coldframe through a Yorkshire March. On a clear day the inside hit 28°C by noon while the air outside sat at 9°C. That gap cooks seedlings fast. So I now prop the lid open every sunny morning without fail."
— Matt, Founder of Greenhouse Stores💡 Tip: Stand your frame on bricks or a paving slab. It keeps slugs out and stops the base rotting on wet soil.
🔧 Matt's Installation Tip: Anchor it down
A light cold frame can tip in spring gusts. We screw the corner brackets to a timber base or peg them into firm ground. Check the lid stay holds the glass open and does not slam shut on a windy day.
Matt's Pick: 6x4 Access Aluminium Coldframe
Best For: Hardening off a full tray of seedlings each spring.
Why I Recommend It: The toughened glass lids slide and lift, so venting on a hot day takes seconds. The aluminium frame never rots and the size suits most beds.
Price: from £579
Comparing glass and polycarbonate cold frames
| Cold Frame | Glazing | From Price |
|---|---|---|
| Elite Min E Lite 4x2 | Toughened glass | £249 |
| Palram Plant Inn 4x4 Raised | Polycarbonate | £329 |
| 6x4 Access Coldframe ⭐ Matt's Pick | Toughened glass | £579 |
| 8x4 Access Large Coldframe | Toughened glass | £659 |
Frequently asked questions
What is a cold frame used for?
A cold frame hardens off seedlings and extends the growing season. It traps warmth near the soil, sheltering young plants from cold and wind before they go out into open ground.
Should I choose glass or polycarbonate lids?
Glass holds heat better and lasts longer. Polycarbonate is lighter and resists knocks, so it suits exposed gardens or homes with children. Both keep frost off your plants.
Do I need to open a cold frame on sunny days?
Yes, vent it on any sunny day. Heat builds fast inside and can scorch seedlings. Prop the lid open in the morning and close it before the evening chill.
How big a cold frame do I need?
Match it to your seed trays. A 4x2 frame suits a few trays, while a 6x4 or 8x4 holds a full spring sowing. Measure your trays before choosing.
Can a cold frame stay outside in winter?
Yes, a cold frame is built for year-round outdoor use. Anchor it against wind and keep the lid clear of snow. It protects hardy plants through the cold months.
Need Help Choosing?
Call our team free on 0800 098 8877