South Carolina's Zone 8a VS 8b

[PalmTreeDude]

So in South Carolina, there is, of course, a zone 8a area and a zone 8b area. BUT I will continuously see CIDPs and Washingtonia robusta in the 8a parts that seem to be thriving, how much of a difference is made by these two zones? Is it only by a few degrees? Or is it just so far south that winters don't get really cold for long? 

Edited November 18, 2016 by PalmTreeDude

[Las Palmas Norte]

Could be that the low end of the 8a temps don't drop that low too often, allowing those palms to gain in size. Also if the deep freeze is ephemeral, then it may only damage the fronds permitting the crown to regrow when warmer weather returns. More northerly 8a zones are challenged in that cold can last longer and is therefore more damaging.

[DCA_Palm_Fan]

^^^  that is exactly it.  VA beaches 8a is different than say an 8a in Georgia or South Carolina in that the cold can and does last longer.  It also hits the 8a minimums more during winter.   I look at climate zones more as a general guide.   I think what actually IS vs what the climate zones say, would look much more like a topographic map than just broad wide zones.  Within a zone 8, behind the a and b, my belief is that there are mush smaller zones that may follow similar contours.   This is how you end up with sizable variances in zones.   Example, just south of St Pete FL there are pockets said to be 10b.  Well that may be true but that's a very different 10b than say Fort Lauderdale, in turn that's why you don't see coconuts everywhere that are large and beautiful in some of those areas.