The Tropical Fruit Forum

Citrus => Cold Hardy Citrus => Topic started by: Citradia on August 28, 2016, 03:17:14 PM

Title: Seasonal freezing hours limit.
Post by: Citradia on August 28, 2016, 03:17:14 PM
Although every site is different and different citrus varieties handle cold differently, etc, does anyone know of a standardized list of number of cumulative hours below freezing during a winter season different citrus varieties can endure before damage or death?  For instance, although Changsha is supposed to survive a low of 5 degrees, how many total hours below freezing could a 10 ft tall Changsha handle before it needs to be protected from any further freeze to avoid damage? I know there are too many variables, but just wondered if any other data out there concerning cold damage other than the lowest temp a variety has survived.
Title: Re: Seasonal freezing hours limit.
Post by: Millet on August 28, 2016, 10:44:15 PM
Citradia the times that a changsha could possibly survive 5 degrees would change with every cold event depending on the preceding temperatures, health of the tree, amount of wind,tree's hydration, insecst. etc. etc. etc.  In some cold event the tree might not even survive at 15 degrees. Millet
Title: Re: Seasonal freezing hours limit.
Post by: Citradia on August 29, 2016, 09:39:41 AM
Yeah. Too much ambiguity. I think the answer to keeping citrus alive in winter is to reduce the number and severity of freeze events via protection, unless one is ok with loosing their tree(s).
Title: Re: Seasonal freezing hours limit.
Post by: Pancrazio on September 04, 2016, 04:49:32 PM
I must agree with you guys. Too many variables. For zone pushers is not just a matter of good calculation and foresight, but also sheer luck.
Citradia the list you imagine would be of incredible usefulness but you can't get one for any plant species. We have to do our best with guesses, myths, urban legends and "i know a guy with an orange tree in his garden! I swear" (And when you go to check it is a trifoliate orange).

What can be done, to narrow the doubts, and honestly i hope people start reporting such stuff more, is reporting the cases when something dies and something else doesn't. For close grown plants this is as good as you can get to get a list from "the most hardy" to the "least hardy" and that list alone would be awesome.

I have started doing this with bananas, but my space is limited, however i find results interesting.
Title: Re: Seasonal freezing hours limit.
Post by: Isaac-1 on September 07, 2016, 08:21:22 PM
Also remember that there are no simple answers, for example I had 4 mature Satsuma trees that were all planted at the same time 15-20 yeas ago, 3 planted in a sheltered location, and one (the smallest) in a less sheltered and somewhat wetter location.  I lost one of them after the cold winter we had 3 or 4 years ago, and it was not he smallest one in the more exposed location.
Title: Re: Seasonal freezing hours limit.
Post by: Millet on September 07, 2016, 10:21:51 PM
Note that the smaller a tree is the easier it can be killed by freezes.  A thick bancs freezes much slower the a thin twig.  This is due to the mass of the wood. - Millet