The Science of Growing a Giant Pumpkin for Rowing on Tumut River

It’s a quiet, sunny Sunday morning in southern New South Wales at the foot of the Snowy Mountains, and thousands of people line the river for a spectacle. What are they waiting for? A man rowing a giant pumpkin down Tumut River—that’s right! But how in the world do you grow a pumpkin big enough for an adult to row like in a children’s nursery rhyme? Well, you need a scientist like Mark Peacock.

Mark is a Tumut local and a horticultural scientist, although his family might prefer to call him a “mad scientist.” He’s the one behind the gigantic pumpkin boats that have sailed down the Tumut River. With a penchant for setting records (he held the Guinness World Record for the world’s hottest chili in 2011), Mark knows a thing or two about growing massive pumpkins.

Mark’s pumpkin-growing journey started as a lockdown project for his family in North Carolina during COVID-19. There, they grew a 340-kilogram pumpkin, sparking Mark’s interest in growing even bigger ones. Fast forward to the present, where he’s harvested a whopping 426kg pumpkin that won top honors at the Tumut Show. But growing a giant pumpkin isn’t all fun and games, Mark says. Factors like soil quality, frost, pests, and diseases play a role long before the plant even sprouts.

So how does Mark do it? His secret lies in ensuring the pumpkin has a good foundation to grow. He even puts sand under the fruit to reduce friction, allowing it to slide and grow to its full size. Too much UV light can also be harmful, so Mark uses a tent to shield the pumpkin. And once the fruit starts growing, Mark is vigilant about removing any new growth to help the plant focus on the main event—growing a massive pumpkin.

But Mark isn’t the only one in the pumpkin-growing game. His sister, Emma, proudly supports him from the sidelines. Mark now aims to inspire more growers in the region to join the Giant Pumpkin Express by sharing his knowledge and seeds with locals. One such member, Ethan Buckley, caught the giant pumpkin bug and managed to grow a 142kg pumpkin on his first try. His goal now? To beat Mark!

With a flourishing grower’s group and a growing interest in giant pumpkins, Mark’s legacy continues to grow, inspiring others to reach for new heights in pumpkin cultivation. Who knows, maybe you could be the next giant pumpkin grower rowing down the Tumut River!