Chatting on the Gardeners' World magazine podcast with editor Lucy Hall, the 67-year-old revealed that despite minor disagreements about their garden on occasion, he and his wife are very supportive of one another.
WATCH: Monty Don shares personal garden transformation
The presenter recalled a time back in 1993 when he had accidentally bought 1,100 trees at an auction instead of 12. When asked to detail Sarah's reaction to the abundance of trees, Monty replied: "She wasn't entirely pleased by it, mainly because we couldn't pay for it and it took a lot wrangling to raise the money.
"But in those days, of course, it was all paid for by cheque and I did it on a Saturday so there was no danger of the cheque bouncing before the Wednesday. So I had three days to raise the money, which I did."
He then went on to praise his wife, saying: "Sarah has always been an entirely supportive partner in crime. One of the things I always say privately and I should say publicly at every opportunity, it's her garden as much as mine. This is not my garden, it's our garden. It's 'We' always.
Monty and Sarah share three children
"Every significant decision, and quite a few insignificant ones, are made by the pair of us in agreement and we have this principle that both of us have a veto over everything. It's a very good way to run a system because what it means is, if you disagree, and we do a lot, you can't do it and say 'Live with it.'
"You might have terrible rows, you might have a lot of persuading, it might mean negotiation. It might take two years before that plant goes in the ground, but when it does you've agreed. But by and large, we generally agree and sometimes it happens that you agree for a quiet life and then, really irritatingly, you realise they were right all along."
Monty met his wife at Cambridge University before going on to marry in 1983. The couple share three children, Tom, Adam and Freya, and are even proud grandparents to George and Daisy Rose.
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