Inspiration For Making A Cold-Frame: Extend The Season

I mainly use my cold frame to start seed pots and to harden off bedding plants a little earlier than my zone normally allows. They do work like a charm for that purpose.

Some folks also place them right in the garden to cover new seedlings they’ve planted early, just situating the frame over top of the patch. When the nights are warm enough, lift it off and put it away until next year…or use in the Fall to prolong the last few weeks of harvest.

These nifty boxes are small but mighty…depending on the zone you live in they can extend the growing season by up to six weeks (on each end Spring and Fall).

They are usually pretty basic with just a wood frame and a clear glass or poly cover (there’s no floor, just the bare ground). Keep the lid open during the day when it’s sunny then close it at dusk to keep the little seedlings warm through the night and to protect from frost.

I’ve been searching online for a few simple tutorials/projects that are free, use recycled materials and are easy to understand…but it’s been a tricky task. A few of these come close since they use old storm windows or glass doors, while others are more advanced projects but still worth a look or two for the inspiration they provide.

For the short amount of time you’ll be using one, I wouldn’t fuss with anything too elaborate or expensive (unless you are making one as a feature in your garden).

If you’re wanting something on a larger scale, I do have a collection of Greenhouse plans on this page (also free).

Quick Note: This isn’t a DIY project, but if you have a tight space and are looking for a vertical solution, see this article at It’s about investing in a ready-made option (vertical cabinet), maybe it will spark an idea for you to hammer something out for yourself.

Now on to the cold frame projects…I’ll be adding new tutorials to this page as I find them, have fun!
Salvaged Windows: The window you use as the cover will determine the size, shape & style of the frame. For this project, barnwood & tin (for the curved/pointed end) were used.

Simple & Cheap: Simple design and made with recycled materials such as a sliding glass door (or any piece of glass) and framed with wood. Simple hand drawn plans available.
Wee Greenhouse Style: I like this one! Four old windows that are the exact same size are needed, check out the local Salvage store, you may find just the thing. Also uses hinges and a sheet of plywood.

Quick & Easy: A roomy 32 square feet, this is made with SUNTUF polycarbonate panels and lumber. Top is hinged and frame rises toward the back for taller plants.
Plastic Tunnel Frame: Made with polyethylene water pipe, wooden stakes, clear plastic sheet and wood strips. Plastic is stapled to the frame.

With Bench: This one’s pretty neat, the box is raised on four legs and has a shelf on the bottom to hold garden supplies.
Redwood or Cedar Frame: Slopes from front to back to accommodate taller plants and gives a tip to sink the frame about 10″ deep into the ground to increase heat retention.

Knockdown: This one’s designed to be setup and taken apart in minutes so it can be easily stored during the off-season. Simple frame consisting of five pieces.
Row Cover Topped Frames: These are a simple frame that features handles attached to the side so they can be easily moved. Instead of using glass, row cover material is stapled around the top of the frame.

Twin Top/Lid: Top lid slants at an angle, this one has two sides. Suggests repurposing a shower door or use a sheet of twinwall polycarbonate.
Just A Cover: No actual tutorial for this, but you don’t need one. This shows a simple wood frame with a sheet of rigid plastic as a cover. If that’s all you can manage for now, that’s all you need!

Window Sash: If you don’t have any spare sashes, you can frequently find overstock for sale at your local lumber store. This one is small enough to reach into but large enough to make a difference.
Resting on Pavers: Features a shallow wood frame but some height is added by using pavers (they also help make a sturdy foundation).

With A Lightweight Lid: Uses inexpensive materials and is built with the intention of being lightweight, easy to remove covers and economical.

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