I told my gardener to plant a lemon and a lime tree. He said how about a 'red lime' tree. I said OK. Neither of us know anything about a red lime. There is hardly anything on the net about them. I did read that they can be red, black, etc. but they do taste like limes. . . no idea when to pick them. Can you help?? Right now there is one yellow fruit about the size of a large lemon on my brand new red lime tree.