In the US, the sudden appearance of large orange pumpkins in country pastures and suburban supermarkets signals the start of autumn just as surely as the changing colour of the leaves or the cooler temperatures.

But beyond acting as an ingredient in pies, bread and spiced lattes, people country-wide have found other strange but creative uses for the seasonal squash. 

Highwood Pumpkin Fest, Highwood, Illinois
This city 30 miles north of Chicago takes all things pumpkin to the extreme. The three-day festival, 18 October through 20 October, starts with an attempt to beat the world record for the longest line of pies (currently held by a man from Atlanta, Georgia, at 530ft 8in), but using all pumpkin pies. The next day, the competition continues as participants try to break the record for most simultaneously carved pumpkins -- 935 -- held by students in Ontario, Canada.

The last day of the festival continues with the Pumpkin Land Regatta, where individual participants race 200- to 300lb pumpkins over a 150yd course on wheeled dollies (with both a motorized and not motorized competition), and concludes with the lighting of the pumpkin walls -- 32,000 jack-o-lanterns stacked on 30ft high walls.

The Great Jack-o-Lantern Blaze, Croton-on-Hudson, New York
More an art installation than a pumpkin display, the Blaze puts 5,000 intricately carved pumpkins on display around the stately Van Cortlandt Manor, 40 miles north of New York City. In addition to individual jack-o-lanterns, creations also include life-size dinosaurs made from carved gourds, a pumpkin aquarium complete with carved fish and coral, and 10ft-tall “jack o’ lantern-in-the-box” that function exactly like a normal jack-in-the-box, but with popping pumpkins.

Open 22 nights in October and early November, the Blaze costs $16 for adults and $12 for children under 12.

Underwater Pumpkin Carving Contest, Key Largo, Florida 
On 21 October, divers will submerge 30ft below the surface of the sea armed with a hollowed pumpkin and a sharpened dive knife, hoping to carve the best pumpkin as judged by the dive boat crew. The challenge, held in the Florida Keys National Marine Sanctuary, is harder than it sounds, since the hollow squash has a tendency to float to the surface. The $85 entry fee covers tanks, transportation and snorkel equipment, and the top three win a dive trip for two in the Florida Keys.