North American Fruit Explorers mailing list at ibiblio

[Scott Smith <scott@cs.jhu.edu>]

I have heard this explanation from many sources and I believe it.  Along with 
it I often hear to cover figs late and uncover early to minimize the problem.

I use aluminum bubble insulation tents as my covering to avoid this problem - 
it reflects the sun during the day and so will not overheat the plants during 
a sunny warm day in winter.  Here is a picture of some figs I covered: 
http://www.slant.com/pictures/orchard/DSC_0027.jpg  The tent was built with 
ordinary staples and is attached to the ground with ground staples; note the 
large area of ground covered to maximize the heat of the ground coming up.  
There is nothing inside the cover besides the figs, in my climate the 
insulation alone provides enough protection; the fact that it protects from 
the desiccating winds probably also helps.  I put a thermometer inside one 
year, and found that when it was about 0F outside it was about 15F under the 
cover.  For even more protection run in a single 10watt bulb which is kept on 
all winter.

Scott z6/7 MD

On Dec 11, 2010, at 11:15 AM, Alan Haigh wrote:

> I have a few loosely science based explanations for why a tree might die 
> when insulated with leaves and then covered with a tarp but survive with 
> only the leaves.  Of course it's still only an opinion based on the 
> research of a couple trees on two different seasons which is hardly very 
> comprehensive and the opinion is little more than an anecdotal observation.
> 
> Here it is.  The tarp traps enough heat during warm spells to break the 
> figs dormancy enough to make it more vulnerable to cold temps.  It's either 
> that or the tree rots from too much humidity (this is how the tree looked). 
>  Or it was just a coincidence and the difference was weather conditions of 
> alternate seasons.
> 
> I hope someone will do some more experiments to sort this out- meanwhile 
> I'm OK with putting my trees in the well house.  Digging them up cuts 
> enough roots to help dwarf them and it's actually quicker than putting up a 
> fence ring and filling with leaves.