It is the usual sunny weather outdoors in Singapore, but inside the Flower Dome at Gardens by the Bay, autumn has arrived.

More than 2,000 pumpkins - the fruit synonymous with autumn - in various shapes, sizes and shades of orange are on display in the cooled conservatory.

Bought from a grower in California in the United States, the 22 varieties of pumpkins include the ghostly white Polar Bear pumpkin and the Knucklehead, which has a warty appearance.

Playing on the theme Autumn Abundance, the attraction has also gone big, literally, with the displays. The Autumn Harvest display ends on Oct 29.

For starters, the centrepiece is a 7.3m-tall "giant" made out of supersized faux fruit and vegetables. Sitting in the middle of a garden patch, he is covered in tomatoes, persimmons and bananas, among other fruit. His fingers, holding a pumpkin, are made of carrots and brinjal. He also sports buff watermelon biceps.

It is a homage to the work of Italian Renaissance painter Giuseppe Arcimboldo, who became famous for his portrait heads comprising objects such as fruit, vegetables, flowers, fish and books.

Nearby sits a large pumpkin house decorated with green foliage and actual pumpkins.

There are also scarecrows and painted jack-o'-lantern pumpkins, familiar sights when Halloween rolls around next month.

Then, there is the head-turning 200kg Atlantic Giant pumpkin that measures about 2.5m in diameter - the largest of the collection of plump fruit that are part of the display.

These are varieties hardly seen in Singapore, says Ms Felicia Chua, 36, assistant director of operations at Gardens by the Bay. Some are so big that the display team had to put up signs to tell visitors that the pumpkins are real.

Ms Chua, who helmed the display concept, says: "Our visitors can experience autumn without having to travel overseas."

Gardens by the Bay staff also had a go at growing pumpkins.

Despite the challenging tropical weather and a lack of garden space, Mr Patrick Hayes, a senior manager of research at Gardens by the Bay, and Mr Sean Koh, an assistant director at the Flower Dome, had some success.

Most pumpkin varieties take months to mature and need hot days and cold nights to thrive. They also need nutrient-rich soil and should be grown in large plots so that their long vines can sprawl out.

Mr Hayes managed to cultivate five Atlantic Giant pumpkins in nurseries at HortPark, though his are not as big as the American ones that were brought in. Mr Koh grew three pumpkins in a garden patch in the Flower Dome, including a Silver Bullet pumpkin that measures 43cm in diameter.

This is the first time that pumpkins have been grown here for a display.

Learning to cultivate the fruit from seeds was a learning experience for both of them.

For example, the pumpkins' flowers had to be hand-pollinated because of a lack of insect pollinators and to encourage the pumpkins to grow rounder. The growers also had to shield the pumpkins from direct sunlight to protect the skin from becoming hard and use fungicide to prevent powdery mildew - a common affliction for plants from the gourd family - from setting in.

Mr Koh, 42, who picked up information from books, consulted online sources and talked to a pumpkin researcher, says: "It was as if we were growing babies. You have to watch and pamper them every day."

Australian tourist Cindy Edwards, 52, was pleasantly surprised to see the Flower Dome overflowing with pumpkins. "I was expecting to see orchids, but this is a nice surprise because the display is so creative. It's a good way to teach visitors about pumpkins."