Assistants use a pulley to position a giant pumpkin on scales at the European Championship Pumpkin W...

Ginormous gourds

Giant pumpkins: 7 scientific reasons these gourds get so chonky

‘Tis the season.

picture alliance/picture alliance/Getty Images

MediaNews Group/East Bay Times via Getty Images/MediaNews Group/Getty Images

As fall rolls around, competitive pumpkin growers gear up to unleash their monstrous gourds upon a fawning fanbase.

San Francisco Chronicle/Hearst Newspapers via Getty Images/Hearst Newspapers/Getty Images

There are pumpkin-growing competitions all over the world. The biggest contest in the U.S. is the Safeway World Championship Pumpkin Weigh-Off, which happens every year in Half Moon Bay, California.