Clive Thompson was a curious 16-year-old when he started out growing mushrooms back in the 1960s.
More than half a century on, he's now selling his Wairarapa business Parkvale Mushrooms.
Watch Clive's mushroom factory in action:
Inside a former dairy factory near Carterton, growing rooms are stacked to the gunnels with rustic boxes filled with sprouting fungi.
Over the years, Parkvale Mushrooms has mushroomed to become one of the biggest Portobello producers in New Zealand.
Clive says he grew his first mushrooms in a Featherston shed after seeing a photo of a mushroom farm in England.
"I was really intrigued but I wasn't very successful at the start."
Mushroom spawn used to come here by boat and it must have got a bit hot travelling through the tropics, he guesses.
It wasn't really until the spawn became available in New Zealand that Clive's business took off.
Then when brown mushrooms came onto the market he says "demand just went ballistic".
"I think they were just about ready to shoot each other in the market to get some supplies," Clive remembers with a smile.
When it's in full production, Parkvale sprouts 7 to 8 tonnes of big flat Portobello mushrooms a week.
Part of the charm of the place is the team atmosphere, Clive says.
"Everyone takes quite a lot of ownership, not just me."
Now that he's nearly 76, Clive says it's time to hang up his cap.
"Someone needs to come in that's young and enthusiastic and can really move the business forward."
Parkvale is very dependent on the restaurant trade and demand for mushrooms plummeted over the Covid years. Now it's only just rising again.
Clive is looking forward to retirement and not waking at three in the morning to check everything's cosy for his mushrooms.
He says he might cultivate a bucket every now and then, though - "just to keep my hand in."