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Cold frame for winter gardening

Super Contributor
Super Contributor

This cold frame traps heat and humidity to help protect and grow vegetables in cold climates.





The project


This project is based on a cold frame but it's way bigger than the ones I usually see.


As always, I was on a small budget, so all the wood and Colorbond are scraps and leftovers from other projects and these dictated the size of the frame.


My wife did purchase elbows and end caps for the poly pipe that I had already, as well as a metal door handle, bungee straps, three hinges and saddle clips from Bunnings. 


I had no experience in making things like this and I didn't have a plan, so I just went with what I had and it kind of evolved as I went along. I did look online for ideas beforehand.




I made a basic frame and joined it to an existing raised bed.




I screwed two sheets of Colorbond to the back to reflect heat.




Elbow and end cap for PVC pipe. I drilled a hole in the end cap to screw it to the frame.




I made a frame for the lid and connected it with three hinges. It's made of light decking boards coming off a solid piece of timber at the back.




I drilled the end caps to the lid, cut the pipe to size and joined them. I covered the pipe with Gorilla tape as PVC pipe can react with plastic in the sun, apparently.




I pulled plastic over the lid and fastened it with strips of old lattice wood, screwed to the frame. Same for the bottom section.




Saddle clips and short bungee to stop wind lifting it. Longer bungee for the opened position.




Job done.




Door handle and close-up of old lattice wood holding plastic firm.




Old storage stands at back so I can reach pots in the rear.




Opened position. I will make side struts later to hold it open.


The drums are insides of old washing machines. I was experimenting to see if I can grow potatoes and sweet potatoes in this environment.


Before long the green growth of the spuds was almost touching the lid and looking very healthy. I was happy with this as we had had nine nights of -1 to 3 degree weather with frosts most nights. The young capsicum and jalapeno were looking good too.


I only have to remove a few screws at the front and the front plastic panel folds back so I can remove the drums and put them back whenever I want.


I got some weather strip from Bunnings and lined the lid and the top of the frame it sits on for a better seal. I have scraps of material pushed into the gaps of the Colorbond as that wave effect goes down the timber frame. I plan to get expanding foam from Bunnings to fill those gaps.


More inspiration for your vegetable garden


Bunnings Workshop member Glenc made this ingenious mobile vegetable garden with a worm farm built in.


mobile planter.png


Workshop member timjeffries built these hot composting bays to turn food scraps and garden waste into nutritious compost.




For more great ideas, check out our 7 ways to build a raised garden bed and horticulturist and Workshop member Adam Woodhamsstep-by-step guide How to build a raised garden bed.


garden bed.png


Valued Contributor

@rattle  This is great, like a mini glasshouse set up ? I love it and great protection for all of your seedlings from the frost 😁

Super Contributor

2 year update...


In this build, I used the heavy duty, clear builders plastic.

I knew at the time that it is not rated for greenhouses and used it as it kept my budget down, by not using a UV protected greenhouse plastic, which was more costly.


The builders plastic lasted a good 18 months, but did start to go brittle in some areas and tore in the wind eventually.


Now, I am here in the middle of May again and I have UV protected Greenhouse plastic coming in the mail.


The micro climate in this thing is fantastic when covered in clear plastic and I some days, I have to put a brick in the opening and prop it open, as it can actually get too hot on a sunny day.


It can get to -3 here with some harsh frosts and I have had great success with potatoes, sweet potatoes, capsicums, chilis and various cuttings and young plants stored in here over the coldest months.

Bunnings Team Member
Bunnings Team Member

Hello @rattle


Thank you so much for that update on your cold frame project. Getting 2 years out of the builder's plastic is pretty good. I personally thought that the plastic would have deteriorated much earlier with UV exposure. But now that you've acquired UV rated covering it should last much longer this time.


Please keep us updated with your progress, we look forward to seeing the new covering attached to your cold frame.




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