A rotting Halloween jack o’ lantern is arguably scarier than a fresh one, but you can preserve your carved pumpkin using a bit of food preservation science. Here is a collection of ways to keep a pumpkin fresh longer.
1. Choose a Healthy Pumpkin
No matter what tips you try, you’ll have the most success if you start with a healthy, undamaged pumpkin. Make certain it’s firm, doesn’t have any soft spot, and doesn’t smell bad. Carved pumpkins with stems tend to last longer than those without them because the stem continues to feed nutrients to the fruit after cutting it from the vine. Use local produce rather than buying a pumpkin from far away, as it may have been cut earlier and sustained damage during transport.
2. Thoroughly Clean the Inside
Remove the seeds and pumpkin guts from the inside of the pumpkin and give the interior a good scrape with a spoon to thoroughly clean the interior. Stray strands and goo are magnets for microbial growth.
3. Disinfect the Pumpkin With Bleach
Disinfect the carved pumpkin with bleach. If your creation is huge, fill a spray bottle with 1 teaspoon of bleach per quart of water and thoroughly saturate the jack o’ lantern with liquid. Completely immerse smaller pumpkins in a bucket or pot filled with water and 2/3 cup bleach. Leave the pumpkin in the bleach-treated water at least 30 minutes and up to 24 hours. Bleach-treating is the most effective way to preserve a carved pumpkin. If you’re only going to apply one treatment, this is the one to choose!
4. Apply Petroleum Jelly or WD-40
Apply a thin layer of petroleum jelly (e.g., Vaseline) or WD-40 to the carved edges of the pumpkin. This seals moisture so the edges won’t shrink and shrivel. It’s important to disinfect the pumpkin before sealing the carving or you’ll trap bacteria and mold inside the layer.
5. Apply a Pumpkin Preservative
You can spray the carved pumpkin with a commercial pumpkin preservative, but it’s easy and economical to make your own. Mix a pinch of borax in a quart of water and spray the decoration. This deters pests and keeps the pumpkin moist. Bleach or salt are good alternatives to borax. Apply the preservative solution daily or whenever the pumpkin starts to look dehydrated.
6. Use Silica Gel Packets
If you live in a region that’s warm and humid, moisture is a problem and not a solution. In this situation, apply a pumpkin preservative less often, keep the pumpkin as dry as possible, and place a silica gel packet inside the jack o’ lantern. The silica absorbs moisture, making it harder for bacteria and mold to get a foothold.
7. Keep the Pumpkin Cool
When you’re not displaying your jack o’ lantern, keep it in a cool location, out of direct sunlight. In cooler climates, this could be outdoors or in an unheated garage. In warmer climates, refrigerate a carved pumpkin to help it last longer. Warm temperatures promote rotting. While sunlight kills many microbes, it also heats the pumpkin and makes it deteriorate more quickly.
8. Try an Ice Bath
If your pumpkin starts to look really bad early on, an ice bath can perk it up. Alternatively, you can freeze a carved jack o’ lantern until it’s time to use it. But, avoid cycles of freezing and thawing because this degrades a pumpkin faster. Bring carved pumpkins indoors during hard freezes and place them somewhere cool.
More Tips for Preserving a Carved Pumpkin
If you’re determined to have a crisply carved pumpkin for the holiday, wait as long as possible before carving it. Consider a glow-in-the-dark pumpkin for early in the month and then carve a design later. You can spray an uncarved pumpkin with acrylic floor wax to seal it and keep it fresh. Keep pumpkins on dry, nonporous surfaces, like countertops and tables. Avoid storing them on concrete, as it can suck the moisture from the base of the pumpkin and is susceptible to temperature changes that can promote rot.
Things to Avoid
Because heat promotes microbial growth, consider lighting a carved pumpkin with a glowstick or flameless candle. Save green fire and flamethrower jack o’ lanterns for the grand finale, since the extreme heat basically results in inedible pumpkin pie. Consider your household when planning pumpkin preservation. Avoid any toxic treatments if you know children or pets will handle or lick the jack o’ lantern. Finally, if your pumpkin rots despite your best efforts, remember it really does look scarier!
- Nummer, B. (2002). “Historical Origins of Food Preservation“. National Center for Home Food Preservation.
- Riddervold, Astri (1995). Food Conservation. Prospect Books (Verlag). ISBN 978-0-907325-40-6.
- Salatin, Joel (2013). “Preserving Food Without Freezing or Canning”. Field of Farmers. Polyface. ISBN 9780963810977.