Why can California zones 9b-11a not grow coconut palms while zones 9b in Florida can?
Here is what I think. If you take a look at zones 9b-11a in CA, most of those places are near the ocean for example- Los Angles, San Diego, etc. The ocean temps affect the air directly above it, keeping the costal areas cooler in sumer, and warmer in the winter. The farther inland you go, the less influence the ocean has on the weather. A more inland area would exprience hotter summers, and colder winters. Temps in most of the costal areas rarely recieve frost, but the constant low temps in winter & cold rain keep the palm cold. They usually die because of fungus caused by cold rain, or because of root rot. They do not like roots wet for very long. They also like soil temps above 70f, which a winter in CA barley has. Frost staying for long periods of time is also bad, they may be able to take 1 or 2 hrs, but longer the period the more it damages. However one could grow one outside most of the year without a problem, although I doubt they will fruit with the low temps. Then you got Flor
