Q.how long does it take lemons to ripen
My lemon tree is in a pot. It has abundant fruit, but some are in their second year of growing and they are still very green. They look about the right size for lemons. The tree is about 5 1/2 feet tall.
Lemon Trees need plenty of water, sunlight and a regular fertilizer schedule.
Here are a few articles that will help you pinpoint the issues.
https://www.gardeningknowhow.com/edible/fruits/lemons/lemons-stay-green.htm
https://www.gardeningknowhow.com/edible/fruits/lemons/how-to-grow-a-lemon-tree.htm
https://www.gardeningknowhow.com/edible/fruits/lemons/growing-lemon-trees-containers.htm
https://www.gardeningknowhow.com/edible/fruits/lemons/hand-pollinating-lemons.htm