A carved pumpkin usually lasts only a few days to about a week before it starts to visibly rot, according to Kansas State University horticulture expert Cynthia Domenghini. An uncarved, fully ripe pumpkin kept cool and out of the sun lasts far longer, because carving opens the flesh to drying out and to mold and bacteria.
To stretch a jack-o’-lantern’s life, scrape out all seeds and loose strings, soak the inside in a 10% bleach-water solution for several hours, and light it with a battery candle instead of a real one, since a flame’s heat speeds up rotting. Bring it indoors if a freeze is forecast, because the pumpkin’s high water content makes frost damage likely. Carving closer to Halloween is the simplest way to have it look fresh on the night.
Source: K-State Research and Extension, “Picking and preserving the perfect pumpkin” (October 17, 2024).
Image: A carved pumpkin decaying a few days after Halloween, photo by Sarah Murray (CC BY-SA 2.0), via Wikimedia Commons.