I was worried about the forecast freeze when I went to bed, but didn’t take the snow forecast very seriously, expecting maybe a few spring flurries.
What I’ve awakened to is a heavy frozen snow pasted to the flowers, fruitletts and leaves of every tree in my orchard and nursery. It is a sight I have never seen before! I was expecting a very brief freeze but now it will take the sun a couple of hours to melt this near ice off of the trees.
Maybe it protected the crop or maybe it’s destroyed it. Anyone have any experience with this kind of weather event? Temps maybe got down to 30 or so. Without the snow, I wouldn’t be so concerned. Light frosts I’ve seen before at this stage.
Snow on the blossoms is usually a good thing! I attached some photos since this is something that happens occassionally in Kansas. These photos are from the same type of storm your having that we had here in kansas several years ago. It was a great crop that year!
The fruitlets sometimes get frost rings if they go through a frost
Attached is a pdf chart from utah showing at what temperatures blooms are damaged CriticalTemperaturesFruitTrees.pdf (2.4 MB)
We got right to 32. No snow that I saw. I covered my potato plants but did not bother with the fruits. I had no damage from similar temps a couple weeks ago. Seems ground temps in my garden/orchard really are about five degrees colder than even scaffold height three+ feet up. So unless my weather station reads below 30 I think I’m OK.
Ground level temp was 27 a couple weeks ago with an “air” reading of 33. Potatoes got nipped, no damage to fruitlets.
Thanks all, you’ve confirmed my suspicions and I will remain hopeful of getting some crop, although some early signs haven’t been good. Hardly any cots, earliest peaches (flavor May) or early and latest nects. The flowers just dried up on those and come right off the tree when lightly brushed. I think because of earlier cold and not lack of early pollinators, although the lack was there. I really didn’t think it got cold enough to do the damage that was done, though.
Every situation is different and all the details are very difficult to keep track of. Such as not only how low the temps get but how long they stay there.
In my opinion a spray with copper buys me up to 3 degrees if its been done within the last 10 days.
Spraying with copper the day of the weather event wont help because it wont have time to work . Ive experienced full crops of fruit when neighbors lost 100%. My callery pear rootstocks offer additional weather tolerance. Callery have a better root system as an example that helps to tolerate drought. The fact the tree has more nutrients helps it tolerate weather events better. I’ve done a lot of research mostly on pears and apples looking for ways to grow them in marginal fruit growing climates like mine. The research i do i feel is important so i’m inspired to do more. I spray my orchard once a year with copper not just to target fireblight bacteria but also ice nucleation / blossom blast bacteria. I suspect you might enjoy this abstract Bacterial ice nucleation: significance and molecular basis - PubMed
Bacterial Ice Nucleation: Significance and Molecular Basis
D Gurian-Sherman et al. FASEB J. 1993 Nov.
“Several bacterial species are able to catalyze ice formation at temperatures as warm as -2 degrees C. These microorganisms efficiently catalyze ice formation at temperatures much higher than most organic or inorganic substances. Because of their ubiquity on the surfaces of frost-sensitive plants, they are responsible for initiating ice formation, which results in frost injury. The high temperature of ice catalysis conferred by bacterial ice nuclei makes them useful in ice nucleation-limited processes such as artificial snow production, the freezing of some food products, and possibly in future whether modification schemes. The rarity of other ice nuclei active at high subfreezing temperature, and the ease and sensitivity with which ice nuclei can be quantified, have made the use of a promoterless bacterial ice nucleation gene valuable as a reporter of transcription. Target genes to which this promoter is fused can be used in cells in natural habitats. Warm-temperature ice nucleation sites have also been extensively studied at a molecular level. Nucleation sites active at high temperatures (above -5 degrees C) are probably composed of bacterial ice nucleation protein molecules that form functionally aligned aggregates. Models of ice nucleation proteins predict that they form a planar array of hydrogen binding groups that closely complement that of an ice crystal face. Moreover, interdigitation of these molecules may produce a large contiguous template for ice formation.”
Kocide 3000 is what i like to use. This year it didnt do me any good on any fruit , the freezes were to cold and to numerous. Never saw this before though there is a first time for everything.
Here in Maryland, big warm up for a couple days. High tomorrow forecast as 87.
Then a few cool days next week, thanks to a coastal storm that will send some cool ocean air via an easterly wind. Since it’ll be moist marine air, no frost issues. Lows should try to stay around 50.
