How to persuade my elderly mother about going in to a care home

My mother is 89 and lives two hours away from me. She has recently stopped driving and lives in a large house with a substantial front and back garden which she still loves and cares for herself. Her garden is her life. Mum is fiercely independent and would never entertain the idea of having a weekly cleaner and does not realise that the house is really filthy. Additionally, she would never accept someone coming in to help her in a carer capacity.

Mum is becoming more and more confused and it is now becoming difficult to have a meaningful conversation with her, which is a great worry. I really need to persuade my mother that it might be time to consider going in to a care home. She absolutely loves her garden and has lived in the house for over 60 years. On the one hand she would be devastated to leave her home and garden after all these years but on the other hand she would enjoy the social side of being with other people and having activities and people to entertain her. There is a lovely nursing home with great reviews that her friend already lives in, so she would know someone straight away.

I would really appreciate any advice on how to broach the subject in a kind, respectful and loving way to help my mother come round to accepting that she needs to be looked after in a safe, clean and sociable environment.