Impromptu Cold Frame for Tender Perennials.

You’re not gonna believe the genius of this impromptu cold frame.  A plastic duvet bag works perfectly to insulate tender plants, plus with a zipper opening it’s simple to vent on warmer days.

I’ve been walking around a piece of garbage on my bedroom floor for 2 weeks. Technically it wasn’t exactly garbage because I had never put it into the garbage can.  It was floor garbage which I think we can all agree is very different.

What happened was, 2 weeks ago I bought a new pillow and it came in a square plastic bag with a zipper. I *knew* this was something I’d be able to use at some point and I probably shouldn’t put it in the garbage or recycle bin. Best to wait until I was absolutely certain I wasn’t going to use it for anything before throwing it out. And it was best to leave it there, right in the middle of my bedroom floor on account of that’s the best way to remind myself that I need to make a decision about it.

I’m sure you see not only the logic but basically the genius of this.

My initial thought was that I could put wool sweaters in it during the summer – but that didn’t seem like the real reason I was saving this bag.  And it wasn’t.  Waking up one morning just barely out of a dream I knew.

The REASON I’d been walking around this bag on my bedroom floor for 2 weeks was because it’s a perfect mini cold frame.

I have a tiny flat of peas that need to be hardened off (oh you don’t know what hardening off is?  K, read this) over the next couple of weeks and I’d been putting it off because I wasn’t sure how I was going to do it. When you harden off cold hardy crops you need to put them in a little cold frame or something to gently acclimatize them to the outdoors.

Enter the impromptu, plastic bag, cold frame.

To do this, you can use almost any bag that has structure. So it needs to be made of sturdy, not flimsy, plastic.  Having a zipper that you can open and close for venting is ideal.

A duvet bag, quilt bag or a large garment bag you would use for hanging several items of clothing in a closet would all be great choices for a slightly bigger impromptu cold frame.

Did I mention the bag has to be clear?  Because it has to be clear. I know there’s only one of you out there that didn’t realize the bag has to be clear so that little mention is especially for you.


If your bag is collapsing on your plants you can get super fancy and built a little frame for the inside of it out of PVC pipes.

Or you can just brace a couple of dowels inside to keep the top of the bag propped up.  You don’t want it squishing down on your plants.

Setting the seedlings in a plastic tray does two things. It helps keep the plastic bag from collapsing inwards and it makes watering really easy.  You don’t need to pull the plants out, you just water into the plastic tray and the plants wick up the moisture.

See? You really don’t need to have all the latest and greatest to garden.  You just need a bit of creativity, some floor garbage and a dream.

Have a good weekend!

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Impromptu Cold Frame for Tender Perennials.


  1. Yabut says:

    I have a tendency to start my tomatoes in a deli chicken tray as it has a clear plastic lid. Thanks so much for this post though as I have several of those plastic cases and can fit more plants in that kind of mini greenhouse. Why didn’t I ever think of that before?

  2. Carrie anne says:

    I’ve saved loads of those bags. What a great use for them!
    I definitely MacGyver (the original….I’m dating myself and Richard Dean Anderson….yummmmy..Oooops sidetracked😂) my garden with what’s on hand.I
    Thanks for another great idea.
    You rock👍👍

  3. Helene says:

    I still have 4 feet of snow on my gardens. I kinda hate you a little bit right now. It’ll pass!

  4. Grammy says:

    Wow. Genius doesn’t begin to describe you.

    I’ve used those bags forever for craft supplies, various toy collections (pioneer people and animals for the Lincoln Log houses, all the States from the large wooden puzzle of the U.S., etc.), and various odds and ends that need to be kept together. But never, ever, did it occur to me to use any of them for a mini coldframe — even while I was searching around for something to cobble together to make one for hardening off seedlings.

    And, yet, now that you’ve shown us the way, I just can’t imagine that they weren’t meant to be used that way all along. That is the mark of brilliance.

  5. Leslie says:

    at last, I knew I needed those things!

  6. Mike says:

    I have been saving 2 of these for the time that the perfect use would present itself. Genius!!!

  7. Lori says:

    Fabulous idea!!!! Now….where did I put all those bags?????

  8. PMMK says:

    Oh, to have a younger mind! Your mind is brilliant and so is your cold frame. And you remember stuff too. Like this thing sitting on the floor just waiting for your next strike of genius.

    I have floor garbage too but I never knew, or maybe I knew but forgot that I knew, that all it’s waiting for is a decision. MY nemesis – decisions. I’m so not good at making decisions. I like how you decided to use your blanket bag. I wonder how many of these end up in the landfill.

  9. Sabina says:

    Genius indeed!

  10. Jane says:

    I came from a long line of pack rats, so I save all sorts of “garbage” because you just never know what they can be repurposed for. For example, those plastic mesh bags avocados come in, I cut off both ends and use them as twist ties for plants. They are stretchy and sturdy, and can be easily chained together. Anyway, zippered bags of all sizes usually end up as storage for odds and ends. BUT, I never considered using them as mini cold frames. What an amazingly genius idea!

  11. Lynn says:

    In the past I have used them for storing Christmas garland, light strands, craft supplies.
    Even guest towels when I know it’s going to be a while till we have guests again.
    Same goes for the smaller zipper bags from large sheet sets. They all make great storage free of dust an easy to see what is in each.
    Problem is grabbing them before husband tossing them 😳.
    I have never used them for a cold frame but I definitely will keep it in mind as it is a brilliant idea.
    Thank you Karen

  12. Lush says:

    Brilliant!!! I cant tell you how many of these I have tossed over the years. Always with the thought that there must be SOMETHING I could use them for other than a garment bag/duvet/quilt storage!! They are so seriously over engineered.

    When I lived in Australia, never had to do the whole seeds/harden off/plant thing. I just checked in seeds, if they survived good, if not, oh well next season.

    Having to learn a whole new way to garden now I live in England. Now I need to go buy a damn pillow! LOL

    Thanks Karen. ;)

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