North American Fruit Explorers mailing list at ibiblio

[Alan Haigh <alandhaigh@gmail.com>]

Of course the later bloomers are less likely to be damaged by late frost
 as long as the frost isn't so late blossoms are open.  This year I 
found out that peaches and nectarines are no more frost hardy  a week 
after petal fall then when in bloom as a mere 29 degrees destroyed much 
of my crop- especially the nects.  Apples were not damaged at all.  It 
was actually more than a week for peaches and several days after latest 
apples had lost petals.

The point is that there are no guarantees and a later flowering 
apple just gives you a slight advantage- one year it will assure you a 
crop maybe the next it will make no difference.  The only year we lost 
peaches here to winter freeze Reliance was as barren as Lady Nancy 
(known for fragile blossoms).   Another year a spring frost froze out 
later flowering peaches but we got crop on earlier ones- go figure.  
Never had a year where peaches known to be fragile didn't  crop when the
 hardy ones did until this one.  That's in over 20 years of growing 
fruit in southeastern NY.