I live in Texas, central part, and it can get cold - down to 14 degrees - for a couple of nights. Doesn't really happen but maybe twice in the winter time. I have 2 lemon trees in containers. Tag on tree says "Improved Meyer," up to 20 feet tall and 20 feet wide. I'm concerned with how to take care of these guys in the extreme cold nights. They are at present about 6 feet tall in the container and I can drag them in I guess but what happens when they get too tall to bring in? Do I constantly cut the tops off? But that would only make them get even wider. I am at a total loss what to do. Anyway of protecting them with cloth or sheet or something?