Couple's mammoth kūmara, cricket ball-sized strawberries

It's bigger than a milk bottle.

Whanganui couple Kirstine and Brendan Lucas' vege garden had produced a massive kumara weighing just under 3kg.

And it's not the first thing to grow bigger than usual in their Springvale soil.

"We have had other freakish crops - sunflowers got to nine feet tall and our strawberries were sometimes the size of cricket balls," said Brendan.

Could it be that the Lucas garden is Whanganui's own version of Findhorn?

The Scottish village of Findhorn first became famous for the giant vegetables grown there in the 1960s.

Sandy soil boosted by horse manure, a temperate micro climate and possible divine intervention have all been credited for the phenomenal size of the produce.

Brendan doesn't know about that but says the large produce grown at his place is just as flavoursome as the smaller versions.

Surplus supplies are shared with friends and neighbours or preserved for winter consumption.

The weekly food bill is greatly reduced and meals in the Lucas household are very healthy.

Brendan said there was no special coaxing or feeding involved.

"The section is on a bit of a slope and the soil is both sandy and peaty," he said.

"And I am inclined to think the sheep that lived on the soil where the kūmara were planted, some three years ago, are a likely contributor to the soil being so nutrient rich."

He says most of the credit goes to his wife, who did the planting and tending.

"All I did was keep it well watered."

The couple moved to Whanganui from Palmerston North two years ago with the intention of living a more sustainable and relaxed lifestyle.

"I hadn't done a lot of gardening before but my wife had always kept a good flower garden," Brendan said.

"The Palmerston North soil has a lot of clay in it but the sandy Whanganui soil is great for growing vegetables."