North American Fruit Explorers mailing list at ibiblio

[<dmnorton@royaloakfarmorchard.com>]



Here are your critical Spring temperatures for Apricots:

Swollen bud --  15  - 10% Kill              -----------------

Calyx red  --     20 - 10% Kill              0   - 90% Kill

First white --   24 - 10% Kill             14 - 90% Kill

First bloom --  25 - 10% Kill             19 - 90% Kill

Full bloom--    27 - 10% Kill              22 - 90% Kill

Post bloom--   27 - 10% Kill             24 - 90% Kill

 

Here is the direct link for the PDF file of the complete chart for most fruit trees.

http://web1.msue.msu.edu/vanburen/fruitfreeze.pdf

 

Hope this helps!

Dennis Norton
Royal Oak Farm Orchard
Office (815) 648-4467
Mobile (815) 228-2174
Fax (609) 228-2174
http://www.royaloakfarmorchard.com
http://www.theorchardkeeper.blogspot.com
http://www.revivalhymn.com

----- Original Message -----

From: Alan Haigh

To: nafex@lists.ibiblio.org

Sent: Tuesday, May 12, 2009 10:04 AM

Subject: [NAFEX] winter, or spring hardiness of apricots

I'm been growing most of the Harrow series of apricots for almost 20 years in the Northeast from Z 5A to 6B.  Can't figure out what makes apricots tick, or stop ticking.  All I know is they are fragile and unpredictable.  Sometimes they survive our worst winters only to die after a relatively minor one.  I have some understanding of the physiology of hardening off and I find no explanation related to that.

 

I used to think it was the early spring cold that killed them, just as they come out of dormancy but I've got a couple of dead ones in different sites this season, one of them very close to the Hudson river where it is very wide and temperature almost never get below zero, so presumably any sudden drops in temp would be moderated.  We had no unusually precipitous drops in early spring or winter this year.  Both trees went into dormancy in beautiful shape by all visual evidence and the weather was fine as the growing season closed.

 

One thing I've learned is planting them by a south wall doesn't help and only makes them more tender.  Same with east walls- haven't tried west.