"Growing citrus below 40 degrees south is a challenge and we're 40.9, so they said it couldn't be done,' John said.
But after eight years of growing citrus, they have not lost one tree, despite the harsh weather of Wairarapa.
"It's quite amazing that we've never lost a tree. The limes lose their leaves sometimes in heavy frosts, but this year they haven't lost any," Jan said.
"The colder weather actually gives us more flavoursome fruit. The oranges and mandarins are so juicy and sweet, people just love them."
Although the snow last week burned the skin of many oranges and mandarins, they are not deterred.
"It's a harsh environment here, but if you're lucky enough to get it right, you can get some good quality fruit. We sometimes have problems with birds and bugs, but you win some and you lose some," John said.
Jan said: "We have a photo of John in 1939 with a snowman and that's the last time he can remember the snow being that bad here, so it was pretty amazing to have that much snow."
John can remember the last heavy snow storm because he turns 74 next month, and Jan is 67, but age is just a number for the pair of them.
"We never get colds or flu anymore because we pretty much live on citrus and I think it's one of the best things you can eat, and we're certainly fitter than we were 10 years ago," Jan said.
"It's a great lifestyle being able to choose when you work and you only have to come out on sunny days, so we can go away without having to worry about anything."
As if working on the orchard wasn't enough to keep them fit, the two are keen cyclists, and have done cycling tours, and Jan is a keen golfer.
John said they were also being kind to the environment by using no sprays for pests and weeds, and using liquid seaweed for frost protection.
"The important thing is that we have a 10-acre block which we've done something positive with and it's green friendly. We aim to improve and be kind to the system with no harsh chemicals. It's also a lot of fun."