I have a Meyer lemon tree, small as it may be, growing and producing fruit in the dead of winter in my dining room. I am thrilled with it's winter growth, which in turn gives me much hope for it's summer growth. I also have two avocado trees that I had to bring indoors for the winter. They are never very happy when they have to come in. I started them from seed several years ago. It's unlikely that they will ever bear fruit, but I enjoy their ornamental shape. My trees are just like me, they do much better when they can be outdoors.