While Derek is no longer infected with coronavirus, it has damaged his internal organs.
In February, Kate gave viewers an insight into what life is like for her family at home with her documentary Kate Garraway: Caring for Derek.
During the ITV programme, Kate revealed she flew out to Mexico with Derek to look into a specialist treatment trial for him.
“I think actually there’s a huge amount of hope for him to improve,” Kate said in the show.
“I think the treatment could be positive. I want to be slightly careful about saying too much because I’m aware everybody will go, ‘What is the trial?’”
Love Your Garden airs on Tuesday at 8pm on ITV.