Ferguson told the United Podcast about overseeing the 2000 move from The Cliff training ground to what is now called the Aon Training Complex.
And Fergie revealed a host of bizarre clauses inserted in the paperwork to buy the land, including leaving areas untouched for Canadian geese and voles, as well as the bizarre potato farm scenario.
Ferguson recalled: "The Cliff was great when I first came, but then the club grew.
"We had to put an extension in the indoor place for the boys to dress because we had no space in the actual building.
"So, then I started to wander around Manchester looking for a piece of ground that we could build a new training ground on.
"We're hunting everywhere, in North Manchester in particular.
"(Former chief scout and academy director) Les Kershaw came to me and his friend worked for Shell.
"He said 'Shell are trying to sell some of their ground over at Carrington'... so we went to see.
"The size of the land we were getting, I think it was 28 acres or something, but there were restrictions which I can't understand today."
Fergie explained: "Part of the restrictions were, in the event of war we had to turn the ground into potato fields.
"And, up at the very end, there had to be an acre or two acres for Canadian geese.
"There were moats and we couldn't change them because voles were living in them.
"We couldn't do anything really."
But Ferguson hilariously added that had been completely ignored by Louis van Gaal, who succeeded his own replacement - David Moyes - at Old Trafford.
The Scot added: "Then I went down after I retired and Louis had put up floodlights and stands and everything!"
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