NATIONAL Party stalwart Lady Flo Bjelke-Petersen had her pumpkin scones - now Lawrence Springborg has come up with the best way to grow the key ingredient.

The Liberal National Party deputy leader and his family have nurtured the biggest pumpkin recorded in Queensland - a monster weighing 304kg.

That's enough to make over 1200 batches of the pumpkin scones.

Mr Springborg took first prize in the Giant Pumpkin Competition at his local Inglewood Show on Queensland's Darling Downs.

He said the monster bettered the former state record of 300.5kg.

"We set out to grow the pumpkin as a bit of a family affair for the Inglewood show, and this one just kept growing and growing and growing," Mr Springborg said.

They bought four seeds at the local produce store, stuck them in ground, added a handful of superphosphate and a bucket of sheep manure.

Mr Springborg's son Thomas, 11, a keen gardener, diligently watered each afternoon.

"The next thing, it's the biggest pumpkin ever been weighed in Queensland," the former opposition leader said.

The pumpkin was 120cm in diameter and 72.5cm high.

The result was a gourd the family had to "wiggle and jiggle" onto a palette so a forklift could raise it into a truck for transport to the showgrounds.

Mr Springborg tips a flurry of pumpkin growing as the locals vie for his title.

The pumpkin's trip to Sydney for the Royal Easter Show was abandoned for fear it would rot on the way.

Instead it will be cut up - with a chainsaw - for its now-famed seeds and a small amount will be made into soup.