Three years ago, I reported winter freeze damage for the peach varieties I was growing at the time. Last winter, we had a significant cold winter event where it got down to about -10F in very early winter. I recognize -10F isn’t supposed to be a critical event for peaches, but it seems to be here. Once again we had winter damage to dormant peach fruit buds, and once again I went through and rated the damage.
Surprisingly, the winter damage at these temps is highly cultivar dependent. Also, equally surprising, is that there seems to be very little research in this area. Everything I’ve read is anecdotal, even observations posted by researchers. Any of the information I’ve seen is based on cursory observations from one winter.
From my perspective, this is a very significant decision making factor for cultivar selection (if the trees don’t produce anything, it’s a show stopper from the start). Yet there is little help available in this regard. I have made records to aid in my own orchard development, but thought that I would again share my results.
A few preemptive comments:
I did not evaluate younger peach trees. Any trees younger than 4 years, I didn’t pay attention to very much, because younger trees seem much more susc. to winter damage of fruit buds. However, if the younger tree came through the winter with a good fruit bud survival, I considered that a success and recorded it accordingly. My thought process was that the already good variety will only get better as the it comes to full maturity.
I seem to notice that “most” newer peach varieties are fairly random in terms of their cold tolerance of flower buds, whereas more of the older standby varieties seem to be more cold tolerant. Even today, I talked with another grower who said his orchard had a mixed bag of varieties which fruit buds survived. As an example, he mentioned Biscoe, an old variety, came through well. He also mentioned his donut peach buds survived well, something I noticed too. With respect to the “old” varieties, I would make a distinction b/t old varieties which are barely extant, and old varieties which are still occasionally grown commercially. The old barely extant varieties are more prone to be non-productive in my experience, whereas the old commercially grown varieties are still occasionally grown partially because they are productive.
In the two years I’ve somewhat formally evaluated (2014 and 2017) I found a high degree of consistency of cultivar freeze damage. Any significant differences are noted in the comments through the report.
The ratings are as follows:
1=very poor (almost a blank tree), 2=poor, 3=fair (not super happy, but something I can live with), 4=good (very full crop-would require some thinning), 5=excellent (almost as if the cold never touched it)
Earlystar-3 (this peach has a very poor growth habit, but is one of the best flavored yellow peaches for this window.)
Spring Snow-1 (Very disappointed this peach came through the winter so poorly. It is one of my favorite white peaches as far as taste - probably my favorite)
Harrow Diamond-4 (Interestingly, the Harrow Diamonds on peach roots came through very well. My one Harrow Diamond on K1 was blank. I’m pretty much not liking this K1 rootstock. It has stalled on this peach and stalled on a couple Euro plums.)
Carene nect-5 (This nect came through great, but for the last couple years the flavor has been substandard. In fact I almost cut this one tree down last winter, but decided to keep it to try the fruit one more time. It looks like I won’t get to try the fruit for a third time this year because this tree bloomed out very early. It’s the only tree at full bloom and partial petal fall. Even though it appears to be winter tough, the early bloom is another strike against it, so I may cut it down after all.)
PF7a - 4
Glenglo-4 (this is a great commercial peach, and I fall in love with it more every year. From a commercial perspective, for an early peach, I don’t understand why it’s praises are shouted from rooftops. The last time I evaluated these trees for winter cold tolerance, they didn’t perform well. I assume the difference this time is due to tree maturity.)
Risingstar-5 (another really good peach for this window, though quite a bit smaller. Like Glenglo, the younger trees didn’t perform well to winter cold tolerance, but tree maturity seems to have made significant difference.)
Nectafest nect-2 (this was a disappointment it did so poorly, especially since it tastes so good, and came through with a good crop last year in the face of spring frost adversity.)
PF9a-007 - 5 (Again younger trees performed poorly, but mature trees admirably)
Harken-2 (I’ve grown this variety at the house for a long time, and grow 14 trees at the farm. It’s just not winter hardy and doesn’t tolerate spring frosts very well either. It has a good flavor, but it’s fuzzy and small. Not a peach I’m in love with.)
Redhaven-5 (This is a commercial staple. Productive. Beautiful color. It’s only drawback is that sometimes we can get a lot of rain prior to its harvest window, which will wash the flavor out.)
Starfire-4 (This one didn’t perform well for cold tolerance as a young tree, but again maturity appears to improve winter cold tolerance. It’s still not as productive as Redhaven and given the two, I’d plant Redhaven.)
Raritan Rose-2 (Peach is a great white, but just not winter tolerant for both test winters I’ve recorded.)
Salem-1 (This is a very unproductive peach, both in winter cold tolerance and spring frost tolerance. I plan to remove these three trees.)
Johnboy-2 (This is variety is a mixed bag for this window. It has poor winter cold tolerance, but decent spring frost tolerance. It is a nice big, tasty peach for this window, so probably the best available for me right now.)
PF Lucky 13 - 4 (Poor cold tolerance as younger trees. Better as trees mature.)
TangOs II - 5
Johnboy II - 1
Hardired nect - 5 (Very productive nect. Unfortunately, only marginal in terms of flavor.)
Summer Beaut nect-4
Tubby Dubby-1 (Our proprietary peach)
Allstar-4 (I didn’t use to like this peach because, although very productive, it got mealy in hot weather. I finally figured out if the mealy prone peaches are picked firm ripe, and allowed to ripen fully on the counter, they are quite good. Hence, I think Allstar has an important place in commercial peaches.)
Glohaven-2 (Again a mixed bag peach. Does poorly in cold winters, but performs well in spring frosts. Very large delicious peaches, which are real eye poppers.)
Loring-1 (This is a great commercial peach, when you get fruit. It is reported to be winter tender, which is exactly what I’ve experienced. I once read a report out of PA, which said Loring came through their test winter well. This is by far the exception, than the rule. Contender is a much better choice for this window in winter challenged areas, imo.)
Bounty-2 (Loser as usual. I’ve grown this peach at the house and had about 10 trees at the farm at one time. It’s been a loser anywhere I’ve grown it.)
Contender-5 (Edited per Warmwx comment)
PF24-007-1 (Very unproductive peach)
PF24c-1 (This was the biggest surprise of all. I only have a couple trees, but these 4 year trees were almost blank. 24c is supposed to be super winter hardy. I thought maybe these were mislabeled, but the fruit ripens at the time its supposed to. Maybe this variety doesn’t harden off as fast as it should (since the winter cold snap came very early) I really don’t have an explanation for the behavior of these trees.) EDIT: These trees are actually only 3 years old and aren’t really old enough to be evaluated fairly. See discussion below.
Julyprince-4 (I just have one tree for evaluation, but so far, I very much like this variety. It came through the spring frosts very well last year and produced a full load of wonderful peaches. The one tree was sick last summer, so I fertilized it extra heavy. I don’t know if that affected winter cold tolerance, which is just based on this one year. I was impressed with the variety enough I made about a half dozen copies of this tree last fall and planted them this spring.)
Baby Crawford-4 (This would be my peach for this window, except Julyprince looks more promising in terms of size, color. Flavor is about equal.)
Glowingstar-4 (Trees improved cold tolerance with age.)
PF25-5 (See Glowingstar note)
Redskin-5 (This peach has fairly poor color, but is very productive)
PF27a - 3
PF28-007 - 2 (Unproductive in late spring frosts, and not very productive in test winters.)
Laurol-3 (Cold tolerance improved with age.)
Autumnstar-4 (Cold tolerance improved with age.)
Victoria-3 (Cold tolerance improved with age.)