Coconut palms is southern California
 

I live in southern Los Angeles county and am considering planting a stand of
coconut palms. I've been told that it will be a waste of time because of
the climate. I've been informed that the coconut palm is a hardiness zone
11 and my home is in the 11 zone. However that farthest north on record for
this palm is in Newport Beach to the south and it is a single palm that is
not thriving.



What is it that makes southern California a tough area for these palms?
What part of the palm is destroyed in a cold winter? The roots? The trunk?
The crown?



Also, does anyone have any tips that I could try in the winter that might
help keep them alive? I've read the book "Palms won't grow here and other
myths," but it doesn't discuss the coconut palm. Are there certain
varieties that are more cold hardy?



Thanks for any help.



Ashton