[nafex] Pin Cherry question

Jwlehman at aol.com Jwlehman at aol.com
Thu Dec 27 11:52:57 EST 2012

In a message dated 12/26/2012 11:27:45 PM Eastern Standard Time, 
jimfruth at charter.net writes:

>  A professor at the University of Alaska - Fairbanks told me that Pin 
> Cherry trees, Prunus pennsylvanica L., that grow there were imported from 
> the lower 48.  That area typically gets -40 F in Winter.  A former NAFEXer 
> in that area grows them and claims that they bear fruit every year.
>   I have Pin Cherry trees, here in Pequot Lakes, Minnesota, where the 
> temperature rarely dips that low and my trees bear fruit only once or 
> twice 
> in ten years.  So what is the possibility that Pin Cherry requires 
> bitterly 
> cold weather to bear fruit?  Anyone have an idea???   

Hi Jim,

Any ideas? Here is my thought. 

Prunus puts on the flowering buds the previous year to flowering. With 
cherry, peach, plum, apricot (all Prunus) the flower buds break bud shell early 
and flower early. Wide swings in early spring temperatures can cause early 
development of the flower pistils then a deep drop in temps will damage the 
stigmas preventing pollination. 

I checked the average high temps of Minneapolis and Fairbanks for February, 
March, April and May.  Fairbanks the average highs are in Fahrenheit is 8, 
25, 43, & 60. For Minnesota (near you) 29, 41, 58, & 69. I suspect your 
higher early spring temps are awaking the pistils and then damaging them. Or, 
the average high at Fairbanks in March is 25 while in your area 41. 41F will 
cause Prunus to break flower dormancy.  

Here in Indiana pin cherry flowers very early. 

Other thinkers? Anyone disagree? 


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