The 10 Best Cold Frames
This wiki has been updated 14 times since it was first published in October of 2016. If you want to maximize the productivity of your garden, you can get your crop off to an early start, extend the growing season, and protect tender clones and seedlings from the harsh elements with one of these cold frames. They take up a lot less space than a full-blown greenhouse, and can be used to cover anything from tiny flower buds to a burgeoning batch of medicinal herbs. When users buy our independently chosen editorial picks, we may earn commissions to help fund the Wiki. If you'd like to contribute your own research to the Wiki, please get started by reviewing this introductory video.
July 02, 2020:
It was a fairly busy round of updates, with half of our previous choices – consisting of the Ogrow Ultra Deluxe, Vegtrug Medium, Quictent Pop-Up, Lifetime Raised Garden Bed and Zenport Mini – all needing to be removed due to availability issues. Some of our new selections this time around include the MCombo Wooden Garden — a solid fir-frame option with magnetic door latches, the Palram Plant Inn — a raised planter with below-deck storage and an integrated drainage system, and the Exaco Trading Company 20375 — which is another covered planter, but this one has a built-in soaker hose.
A few things to think about for this category:
Protection: By definition, all offerings in this category should give your plants some level of protection from the elements, but how much can vary considerably. While soft-cover options – like the Gardman Multi and Zenport Greenhouse Cloche – might do a good job at raising the temperature for your seedlings by a few degrees, it’s questionable whether they’ll stand up to high winds. We recommend anchoring all cold frames whenever practically possible, but it’s a preventative measure that becomes especially important with lighter options like these.
The Exaco Trading Company Year-Round features a built-in screen below it’s removable top panel, so you can let in a bit of breeze for your plants as the summer starts to heat up, whilst still offering them some wind cover and protection from hungry birds and small animals.
Ventilation: Many gardeners will agree, the best way to harden your plants off is slowly, by gradually increasing the amount of fresh air you allow them in small increments. While the Zenport Greenhouse Cloche and Gardman Multi include roll-up flaps to let some breeze in, models like the Palram Plant Inn and Exaco Juwel BioStar 1500 feature adjustable latches to help you prop their tops open just a crack. The Flower House Pop-Up and MCombo Wooden Garden have large doors that open wide, but still provide wind cover from three sides, and the Giantex Garden Portable boasts well-thought-out hardware that gives users full control of what angle its top panels are propped open at.
Capacity: How many plants are you hoping to hold in here? The MCombo Wooden Garden has two adjustable shelves that help increase its capacity, and the Palram Plant Inn comes with plant hangers to help facilitate vertical growth for vine plants, but barring a few assets like that, for the most part, the simple metric that determines a cold frame’s capacity is the size of its footprint.
While the Palram Plant Inn has a footprint of nearly 15 square feet, the Exaco Juwel BioStar 1500 falls just short of that at 13 feet, and the Giantex Garden Portable takes up roughly half the space of the Palram, with a footprint of less than eight square feet. If you’re unable to find a cold frame that meets your needs, then you might have more luck with a portable greenhouse.
And, if you want to get an even earlier start on the growing season, or possibly keep it going all year long, right through the winter, then you might be interested in checking out or lists of best T5 grow lights, LED grow lights and LED grow light bulbs.