Is it growing in full shade? The new growth is stretched.

what is the meaning of "stretched" about a lemon tree?

also, is this the only kind that has reddish coloring and no thorns?

it has been growing maybe 3 or 4 years, when will it start to produce lemons? it is only about half of an adult's height.

"Stretched" in any plant means that the distance between the leaf nodes is larger then normal, it is due to lack of sunlight. Is it a seedling, is it grafted, is it in a container or in ground? You have to give more background information about it.

amazing. yes, it is located in an area that doesn't get a lot of sun.

i think that i just put a cutting in the soil, and it just grow.

Preppystud, what is your growing zone? Can you post picture of the whole tree from ground to tips? If it is a cutting, it will flower and fruit for you sooner than seedling tree will do. I have one unknown lemon tree that has purple new growth when it's outside, but when it grows indoors ( it's in a container), the new growth is green.