'Green knees' isn't an expression as such. It means exactly what it says - if you've been kneeling on grass and plants all day doing the gardening, then your knees will be stained green at the end of it. What interests me is why people are asking about it. Another Russian member posted the same question yesterday.

Yes that is quite possible too! I do not know the whole context but yes that is probably right in this situation :)

Likewise, I'm glad you got your answer, Andrew, but I think it has the opposite meaning. Bill says 'If your knees AREN'T green at the end or the day, you ought to..' . He's suggesting - jokingly - that our lives probably aren't fulfulling if we don't do lots of gardening! What do you think?

Hi Great Glad you got the answer, as I said it is maybe he is using it as a motivational comment, to work harder at your life rather than getting Green Knees! :) Gillian

Thanks! Actually, there was not another member, that was I )) I hoped russians can help me, but they didn't.