Q.when will i know to transfer my lemon tree from pot to ground?
My lemon tree is about 6 months old and is getting a little big in its pot, so I was wondering when can it be transferred to the ground?
I'm not sure why you didn't plant your lemon tree 6 months ago when presumably you bought it. Now it's almost winter, which is not the best time to plant a lemon, which is especially sensitive to cold. If it had been planted in the spring, it would have had 6 months to grow roots and gather strength to face the winter. Zone 8 is at the northern limit of the lemon range. At this point, I would suggest you overwinter your tree in its pot - here's an article to help with that. https://www.gardeningknowhow.com/edible/fruits/lemons/growing-lemon-trees-containers.htm
Next spring as soon as chance of frost is passed, select your site and plant the tree. This article is rather extensive but will give you lots of good information: https://aggie-horticulture.tamu.edu/citrus/lemons.htm