Further Evaluation of Winter Damage of Peach Buds

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

Garnet Beauty-5


Early Redhaven-4


Silvergem nect-3

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.)


Saturn donut-4


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

PF15a -5

Johnboy II - 1

Hardired nect - 5 (Very productive nect. Unfortunately, only marginal in terms of flavor.)


Summer Beaut nect-4

Ernies Choice-3

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.)

Canadian Harmony-3


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.

Coralstar-1 (Unproductive)

Sweet Breeze-2

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)

Sweet Cap-4

Carolina Gold-3

Fantasia nect.-3

Lady Nancy-3

PF27a - 3

PF28-007 - 2 (Unproductive in late spring frosts, and not very productive in test winters.)




Laurol-3 (Cold tolerance improved with age.)

PF35-007 -3

Autumnstar-4 (Cold tolerance improved with age.)

Victoria-3 (Cold tolerance improved with age.)


Thanks for the report. Somewhat surprisingly I had -15.4F in December(12/18) and on my forced branches of Redhaven it looks like I have 80% or greater survival. Last winter we had -10F two nights in mid January and I had probably 1/3 of the blooms I should have had. And lost more fruit to our freeze last year.

Good point on the trees getting hardier with age. Maybe that is what is going on for me.


It’s snowing right now and ALL of my peaches and nectarines are in full
bloom, but the temp is only 36, so I have my fingers crossed. I thought about
spraying KDL, but decided not to. It’s supposed to go down to the mid 20’s
wednesday and thursday and the KDL will definitely be sprayed. I’ll let you
know the results later in the season.

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My Harrow Diamond is on K.1. (Sad face)

I grafted a bunch of stuff to K1… I might have to start over on different rootstock.

Contender? I would guess that must be a 5?

You know how much I respect your opinion and experience.

The only experience I have had that contradicts yours is PF 24 C. In our snowiest and through several single digit cold blasts In early 2014, Of the three peaches I had at the time: PF 24 C (planted 2010), PF 1 (planted 2011) and Autumn Star (2012?).

% of flower bud damage: PF -24 C 20%, PF-1 50-60% and Autumn Star 80-90%.

I agree that younger trees are more susceptible to cold damange. Autumn Star would have withstood cold weather that winter better had it been as old as PF-24C.

Thank you for your report. It’s really helpful to look for other bud hardiness peaches for my area.

Matt and Warmwx,

I probably should have mentioned K-1 has some good attributes. It does produce larger sweeter fruit than peach roots, and it it sort of nice that it keeps the vigor way down, so there is hardly any pruning. But that it allowed all the fruit buds to freeze off is a deal breaker for me. I had Harrow Diamond trees on either side of the Harrow Diamond on K1, and they had good fruit bud survival from the winter.

Thanks for pointing that out. I corrected my post above. Contender was a 5. It’s a tough peach.

Thanks Mamuang for sharing that info. I agree, I’m scratching my head about what I saw with 24c. I’ve always heard it’s very winter hardy. This was the first year I was able to evaluate these trees, so maybe it’s a fluke.

Wait a minute, I just noticed in my records those trees are only 3 years old, not 4, so that may be it. I shouldn’t have posted the results of 24c. I’ll make an edit note above. They have grown fast and had good crops last year, so they fooled me into thinking they were older, when I was recording the info at the orchard. Good catch!

Sweeter yes but I’ve never seen larger on nectarine or pluots in fact quit a bit smaller. It’s not very compatible with peach or apricot. Better unions on pluot and plum.

Thanks so much Olpea!

Here was winter 2008-09 for here…That winter had several days that hit -20Fs and -10Fs…

Here was my (i shared this on GW years ago) Reliance peach July of 2009.

Obviously it sustained those temps and flowered. My best guess why this endured that cold was that this tree (long removed) was in the shadow of the house the entire winter (no winter sun) and that those cold temps came in the heart of winter (mid Jan).


Steve, do you think the smaller fruit size might be a result of how
you water restrict your trees.

I wonder if that might have something to do with it?

Here is one evaluation for plums where they recommend against dry conditions.

Here’s another one in Growing Produce:

“This rootstock has been in the 2001 and 2002 NC-140 peach rootstock trial showing promise as a peach rootstock with high yield efficiency and enhanced fruit size.”

Well K1 gives smaller fruit under my conditions than Citation. Maybe it is the water regime. Citation is said to lack drought tolerance but I haven’t seen that. At any rate fruit size doesn’t matter to me much, some, but not much. I’d much rather have high brix than large fruit.

Ray I guess you’ll get to see what it does for you.

Under conditions where K1 enhances fruit size I’d expect much lower brix than I’m getting.

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Lol, I doubt anyone can get the brix you’re getting. If I hadn’t lived through such a hassle trying for a record, I’d recommend you go for the highest brix record for peaches. Except for all the paperwork, I think it would be a walk in the park for your fruit.

Thank you Olpea!!!

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What an interesting read on a blustery Sunday afternoon! Really glad that you pointed out the maturity angle. Thanks for being there Olpea!!!

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I have made a list of your peaches and nects that scored a 5. All except Carene.

Those are: Garnet Beauty, Sure Crop, Rising Star, Red Haven, Contender,
Redskin, TangO II, PF 9a 007 and PF 15a.

I would like to ask if you could comment on their taste and disease susceptibility, please. I believe it would benefit many of us.

Thanks again very much.



I’ve seen very little bac. spot on any of the varieties you mention (mostly no bac. spot). I do spray for rot, so I don’t see much of that on the peaches. Likewise with scab. Occasionally I see some inking, but I don’t recall seeing that on any of those varieties. So overall, I would say the 9 varieties listed are fairly disease resistant, as far as peaches go.

Flavor is a bit harder to evaluate. Typically the later peaches taste better because the early ones here get a lot of rain. Generally things start to dry out by the time Redhaven starts to pick, so it tends to be consistently pretty good, unless we get a lot of unusual heavy rains around that time. By the time Contender picks (3 weeks later) it’s generally been pretty dry for a while, so it’s pretty good. 9a-007 picks a few days before Redhaven and it acts a lot like Redhaven in terms of flavor.

TangOs II is the only stand out one of the bunch. It’s a white peach very sweet like Saturn, but much firmer. The rest of the yellow peaches on the list are pretty similar in flavor, as long as too much rain doesn’t wash the flavor.

Redskin is a good tasting late season peach, but it sometimes shows a little green on the stem end, even when it’s ripe. Something that probably wouldn’t bother most home growers.

Lastly, peaches which I scored 4, came through the winter pretty good too. Sometimes I might give up a little on winter hardiness to capture a peach which is very productive in spring frosts or other areas. For example, Glengo may not be the most hardy peach out there, but its overall positive attributes make it one of the best early commercial peaches for the Midwest, imo.


Thank you very much, Mark.
I do spray for bac. spot and will do for brown rot if I have any peaches this year. In my area, growing peaches without chemical spray at all is a pipe dream.

I have grafted several peaches last year. Redhaven is the only one on the 5 list. Need to look into T bud those varieties this summer. I have had modest success T budding. Need to work on improving the skill.

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Mark, I was out looking at which peaches are the least far along at this point in my orchard. All of these are barely swelling now. I can’t add any hardiness data but generally the later bloomers have more chill requirements and are more hardy … generally.

John Rivers Nectarine - a classic old white -fleshed nectarine which is also pretty good for rot. All of my other nectarines were very far along and I lost some flowers, this guy really bucks the trend.
Okubo - this is an extremely late dark orange flesh freestone peach, I have not tasted it yet though due to thefts plus first stock dying.
Qui Xiang Mi - this is a white cling peach which has not fruited yet for me.
Zin Dai Jiu Bao - this is an excellent very large white clingstone peach.
Heath Cling - a very late old clingstone.

These ones were only a little bit swelled:
Indian Cling

and all the rest were further along. Here is a picture of a tree (St. John) that is just a little bit further along than the Clayton.

Let me know if you want wood on any of these peaches Mark, they are probably still dormant enough. Its too bad there are lots of clingstones in the list, they may not sell too well. But if thats all you had for sale I’m sure they would sell like hotcakes! The Zin Dai in particular is a world-class peach in all other respects, and its also very grower friendly in terms of picking, it can/should be picked a week or so before market.

For the cots, Zard is mostly OK and Montrose looks like 1/3 of the blossoms may make it. Here is a shot of what most of the apricots looked like, and then a close-up on the Hoyt Montrose: