I have an asian grapefruit tree. It is only a few months old, (grown from seed), but is about 8" tall, and has several leaves. I told my brother, and he didn't believe me, so he took a bunch of lemon and lime seeds and stuck them in a pot of dirt. Well...guess what grew! Now he cannot tell the differnce between them! So I am aslo a proud owner of a mini lemon or lime tree!!!
I read somewhere that when you grow citrus trees, you must remove the first fruit. It is the "mother", and she can tend to make the fruit tart, but by removing it, allows the other fruit to grow more plentiful. Now... I do not know if that is true, so don't hold me to it!