Neath Port Talbot,
United Kingdom 
We bought a lemon tree last year which had green fruits on it. I cut them off, repotted the tree and afew more fruits appeared. Great! However, they're still green 5 months on and I'm sure this isn't right...
Does anyone know when to prune lemon trees, and how long we should be waiting for the fruit to turn yellow?
26 Feb, 2011
Answers
Highly unlikely to ripen from what I understand, in the UK the tree is viewed as an ornamental.
26 Feb, 2011
The yellow just makes them look pretty, anyway. They are perfectly edible green, as long as they are big enough to give a decent amount of juice. The ones in the grocers are picked green and gassed to make them turn yellow. Around here, If we let them turn yellow, they are frequently overripe--dry and bland.
26 Feb, 2011
Thank you everyone!
I shall be picking them tomorrow and using them asap :)
27 Feb, 2011
I've had my lemon tree for a year now and the original fruits are only just ripe now!!
27 Feb, 2011
If the tree is in a heated greenhouse, they probably won't turn yellow until they are at least 8 months old, and/or they get night temps below 10ยบ C.
26 Feb, 2011