Gilchrist said growing the pumpkin required many soil tests, three to four hours a day of pest and fungus control, fertilisers, and phosphorus and potassium to accelerate growth.
The biggest pests were powdery mildew, fungicides and aphids, he said.
Pumpkins thrived in warm conditions, he said.
“They love the warmth; anything under 10C, they slow down in their growth.”
He said Rangitīkei was ideal for growing large pumpkins because of its warmth.
The pumpkin is testing the suspension of the ute it is displayed on at McVerry Crawford in Marton. Photo / Fin Ocheduszko Brown
Gilchrist’s 546kg effort this year is not his biggest. In 2024, he grew a 578kg pumpkin.
The New Zealand record is held by Waikato farmer Tim Harris, who grew an 844.5kg pumpkin in 2021.
A rewarding part of Gilchrist and his family’s years of growing giant pumpkins is the friends made around the world.
“You meet a whole lot of people through it. It’s a small community but everyone is out to help everyone,” he said.
Gilchrist has friends who grow giant pumpkins in South Africa and Australia.
He said the hobby was “massive” in the United States because growers invested heavily in facilities, such as greenhouses with automatic heaters, doors and fans, which enabled sustainability.
New Zealand growers were fading away from the hobby because it was hard to import seeds, Gilchrist said.
In 2016, the Ministry for Primary Industries introduced regulations to make importing seeds more difficult to prevent disease.
“If they can get the seeds back into New Zealand, then there will be a lot more growers popping up,” Gilchrist said.
Gilchrist hoped to step away in future and have someone take over pumpkin-growing on his farm.