Michael Foster, 62, and Susan Cooper, 63, had profited to the tune of around £400,000 over six years, and they had sent most of it to a Kenyan village where they were regular visitors, The Daily Telegraph reports.
It was described in court as the "most unusual cannabis growing case of its type".
The couple paid for life-saving surgery, bought computers for a local eye hospital and provided schooling for poor children in Africa. Cooper had even paid for a young man's surgery after he was told he had two days to live.
The pair were caught when a police officer was pursuing a burglar nearby and he recognised the distinctive smell coming from their farmhouse.
The judge that sentenced the couple said he accepted that they were of good character, but then went on to say: "I am sure you were doing good things in Kenya with your drugs money; whether that was to appease your consciences I can only speculate."
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