Cold weather news from the Great Lakes Fruit Growers

Leslie Huffman, apple specialist at the Ontario Ministry of Ag and Food, posted a question to the listserv today about extreme temps and bud kill. I’ve pasted in some of the responses below. You may also want to check the OMAFRA Apple webpage at

Stay warm, everyone!


No “official” table I am aware of for the Jan & Feb months.   My operating guidelines are that I expect at least some fruit bud loss in these months with temperatures of:
Apple & Pear  -30 F
Apricot -25 F
Tart cherry – 20 F
Plum (European) & Sweet Cherry  -15 F
Peach & Nectarine -13 F
This is with varieties and rootstock adapted to the area and no significant warm spell shortly before the cold event.
On January 16 & 19, 1994 lows of  -17 to -22 F caused nearly complete peach crop loss in southwestern Michigan and widespread damage to peach wood.
I agree that there are a number of factors that influence the amount of cold damage. Main factors are minimum temps, duration of cold temps, acclimation and previous season’s crop load. Having said all that, the rule of thumb for peaches I learned from Dick Hayden is:
Start to see some cold damage at –10F and for every degree below –10F you lose 10% of your flower buds. At –20F expect complete flower bud mortality.
Temp here right now is –13 F so assuming this is as bad as it gets, we have some early thinning occurring but still expect a full crop of peaches.
Peter M. Hirst
Department of Horticulture and Landscape Architecture
Purdue University
625 Agriculture Mall Dr.
West Lafayette,  IN  47907-2010



This is what I remember:

-13 F  -25 C, kill peach flower buds
-20 F  -29 C, kill peach veg buds and wood damage, kill trees? cherry, plums bud and wood damage
-25 F  -32 C, kill apple flower buds

-40 F  -40 C. kill apple trees



Leslie and all,

Minimum temps and damage to buds for the fall/Winter/early spring are moving targets.


The Ontario Tender Fruit and Grape Marketing Boards hired KCMS and work with CCOVI at Brock University (Grape only) to post LT 10%, LT50% and LT90% at 2-3 week intervals throughout the dormant season.

The tender fruit is posted on the Ontario Tender Fruit Producers’ Marketing Board, but it has not been updated recently. I just mentioned that to the CEO of the Board and she is going to get it updated when one of her staff returns from vacation. I can send you the latest grape info from the website if you want.

Nothing going on with apples yet.

Wind machines have been on 3 times for grapes already this fall/winter and I would say it would be the same for tender fruits (peach, nectarine, plum, cherry, pear).


There have been some crazy spikes in the temps in Niagara – Dec 16-17 and Dec 24-25. Lows recorded on Dec 16-17 ranged from -14.8C at the lake and -25.1C on top of escarpment at Grimsby (mainly grape and apple area). Temperature inversions have been strong ranging from 1.6C to 9.1C at the 40-50 foot height (I suspect the 1.6C location is near the influence of a wind machine.

source – Vine and Tree Fruit Innovations (formerly Weather Innovations Network).


Dr. Richard Layne did some freezer work on peaches in the 70-80s for his screening of Harrow selections but not sure how many standards he did.

Hope this helps.


Ken Slingerland  -  Wind Machine Specialist

Lakeview Vineyard Equipment Inc.,

40 Lakeshore Road, RR5,

Niagara-on-the-Lake, ON L0S 1J0

Shop: 905-646-8085

Toll Free: 1-866-677-4717

Cell: 905-651-0057


Here, we are seeing a nearly 70 degree temperature rise in 48 hours (-12 F. to +56 F.), and am expecting a 50-60 degree temperature drop in the next 36 hours.
I’m ready to retire…


Jon Clements
<IFTA 2013 Boston, February 23-27, 2013.>