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Last week, my kids selected a couple of nice large pumpkins from the local pumpkin patch here in Studio City, CA. They are eager to start carving them, but in my experience jack-o’-lanterns begin to rot just a few days after they are cut, so I’m encouraging my girls to wait until a few days before Halloween. I don’t think they’ll be able to hold out much longer, however. So I went online to find out how to prevent fungus and mold from growing like crazy on exposed jack-o’-lanterns.

If you search Google for “how to preserve a jack-o’-lantern” you’ll get literally dozens of different preservation techniques. Here were just a few recommendations I came across:

Spraying or soaking the jack-o’-lantern inside and out with:

WD-40

Lemon juice

Lysol

Athletes foot spray

Vaseline

Water/bleach mixture

Acrylic spray

White glue

Commercial pumpkin preserving solutions

(Or some combination of the above.)

Others suggested putting the jack-o’-lantern in the freezer.

Surprisingly, I didn’t find much in the way of tests that compared the different preservation techniques side-by-side. I found just one experiment from 2006, which compared the preservation qualities of white glue, acrylic spray, Vaseline, bleach, and Pumpkin Fresh (a commercial preservation product). It turned out that the control jack-o’-lantern (the pumpkin that received no treatment) fared just as well as the bleach- and Pumpkin Fresh- treated jack-o’-lanterns.

In the conclusion to the experiment, the amateur jack-o’-lantern scientist wrote, “Our findings in this experiment were surprising to us. It seemed that some of the so-called preservation methods recommended for pumpkins actually accelerated their decay. This was particularly evident in the white glue treatment. We suspect that the glue may have provided a medium that nourished the mold and encouraged it to flourish.”

Testing different jack-o’-lantern preservation techniques sounds like it would be an excellent project for someone to undertake. For now, I think I will go with the bleach preservation method. Happy Carving!

Mark Frauenfelder

Mark Frauenfelder is the editor-in-chief of Make magazine, and the founder of the popular Boing Boing blog.


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Comments

  1. Shane Graber says:

    Dr. Frybrain’s Pumpkin Embalmer (http://www.drfrybrain.com/) is nothing more than good ‘ole calcium hydroxide (i.e. pickling lime). It costs ~$3 and is in the canning aisle at your local supermarket. Compare its MSDS against the solubility and melting points of calcium hydroxide on wikipedia….

  2. EchelonForce says:

    Our hackerspace ccckc/hammerspace just had a class on pumpkin carving from a very skilled carver (think 30 intricate carvings a season)… her recommendation was to:
    1. Soak in plain water for an hour. Basically over hydrate it.
    2. Seal cuts in pumpkin over with press-n-seal.
    3. Refrigerate if necessary to hold off rot (only works for a few days). Don’t freeze, this destroys cell structure…

    Mostly though you just have to wait until it’s closer to display time…or carve a new pumpkin every few days… You can use weak bleach water to kill existing rot but should rinse it afterwards.

  3. johnoly99 says:

    Or, you can build a punkinbot and just carve a new one in a few minutes with some digital wizardy!

    http://punkinbot.com

    Think eggbot-on-steroids!

  4. eca says:

    WHAT EVER HAPPENED TO eating it???

  5. I have two neighbors who have carved pumpkins on their front steps already. One house gets a lot of sun on the steps, one is shaded. The pumpkins in the sun are shriveling at an astronomical rate compared to the ones on shaded steps.

  6. ka mitchell says:

    floral preservative spray? Rootone(indole-3-acetic acid)spray? Sulfured like oldtime molases ? And sprayed with sealer like a urethane?Alum solution?Foot fungus spray? Now I seem to be getting fatigue- silly .

  7. Heath Israel says:

    IMO, some of those ideas need more though. At some point, something is going to nibble on that pumpkin (in my case its usually the night after I put them outside…in many cases its probably once they get to the landfill). Saturating them in poison to get a few more days out of them is an awful idea.

    1. Heath Israel says:

      Throw a ‘t’ on the end of ‘though’…sorry.

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