vp999
Omono
They're calling for 39 and 308 the next 2 nights here, Im just going to leave my tropicals out.
Blasted Freeze warning next two nights.
- Thread starter penumbra
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vp999
Omono
I mean 39 and 38 … not 308 lol. These are the ones that survived when my greenhouse got down to 28 over Christmas.
Baku1875
Shohin
Sending prayers to the cold weather homies, good luck. 
check the madden julian oscillation for 10-20 day weather trends, looks like this was definitely triggered in part by phase 1 MJO (extreme cold anomalies east of the rockies)
Here in south florida it has been monsoon for the past two weeks but it is settling down (phases 7 and 1 MJO)
Phase 6 seems probable after the first week of May which would imply elevated heat for everyone in the US except along the edge of the west coast.
We are also transitioning into El niño very aggressively for the first time since 2019 so there will be many moving parts this year.
62% chance of El Niño developing during May-July 2023 according to the CPC/NCEP. If that evolves into a strong ENSO into winter, it could mean dangerous cold for the southern half of the country combined with extreme precipitation, which would be the equivalent to subtracting 1-2 USDA zones for some.
check the madden julian oscillation for 10-20 day weather trends, looks like this was definitely triggered in part by phase 1 MJO (extreme cold anomalies east of the rockies)
Here in south florida it has been monsoon for the past two weeks but it is settling down (phases 7 and 1 MJO)
Phase 6 seems probable after the first week of May which would imply elevated heat for everyone in the US except along the edge of the west coast.
We are also transitioning into El niño very aggressively for the first time since 2019 so there will be many moving parts this year.
62% chance of El Niño developing during May-July 2023 according to the CPC/NCEP. If that evolves into a strong ENSO into winter, it could mean dangerous cold for the southern half of the country combined with extreme precipitation, which would be the equivalent to subtracting 1-2 USDA zones for some.
penumbra
Imperial Masterpiece
Last night only hit 36F. Tonight is going to be a little colder. Calling for 30s on Tuesday night as well.
markyscott
Imperial Masterpiece
I ended up putting all the broadleaf trees back into the high tunnel. I’ll know next year not to bring them out until May.
- S
AaronThomas
Omono
I'm actually a bit jealous of the cooler temps... already too hot here.
Scorpius
Chumono
I have freeze/frost warnings all week now. Ugh... At least I'm home on vacation this week.
hinmo24t
Masterpiece
good thinking. in MA we are getting high 30s a few nights. ill position my shelf a bit more protected and my
toms and pepper starters ill put in the garage overnight
toms and pepper starters ill put in the garage overnight
Gabler
Masterpiece
What is it about the physiology of Japanese maples that makes them unusually sensitive to a late-season freeze? All three species of Ficus trees that I keep easily handled a late frost that wilted the new leaves on my Japanese Maple seedlings. The seedlings bounced back with more new leaves, so there was nothing ultimately lost, but it just seems weird that a temperate species would have so much trouble with normal springtime temperature fluctuations, whereas a tropical species can handle it without any sign of frostbite.
, lows the rest of the week in the mid forties.
Baku1875
Shohin
(off top of my head from anecdotal maple vs ficus facts)the waxy vs 'unwaxed' cuticle probably plays a role in the vulnerability. maples dont have thick waxy cuticles that ficus have, so they lose a lot of strength if they invested in early spring growth and get hit with a frost, but can handle plenty of cold if it comes during mid winter dormancy. Possible that the increased sap flow during spring can conduct the cold through the vascular system via the damaged buds in younger trees resulting in more damage.
Ficuses do have the milky sap flow, it's active year round for me, im not sure if the sap slows down in colder climates or if it can be a vulnerability. During the 3 or 4 unusual 'cold fronts' in my area this winter (~35-40F lows at night which my trees aren't used to at all), my tiger barks and benjaminas were unharmed, bucida spinosas got some browning/graying of leaves and lost a few twigs. They have tiny leaves with a very thin cuticle.
Would be good to hear someone else who is actually familiar with the situational physiology differences chime in.
Michigan Tree Murderer
Masterpiece
Captain check the weather every 3 hours reporting... 
Easy solution here Sir. Just leave them outside. I'm tempted to do that all the time. 29 F here tonight.
penumbra
Imperial Masterpiece
It was 30F when I got up this morning. Predicted was 34, so I am a bit gun shy.
I wish I had a job where I could be wrong most of the time and still get paid.
I wish I had a job where I could be wrong most of the time and still get paid.
Ha ha yes, And I have never heard one of them say, "Well we sure blew it on yesterdays forecast again didn't we?" 28 here. I moved a bunch but 2 large ones recently repotted stayed out because I was tired. LOL
ForThemWhatCare
Mame
How much watering represents a thermal barrier?
Dav4
Drop Branch Murphy
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I personally couldn't quantify it. The idea is that the water drops on the leaves must freeze- and give off heat- before the water inside the leaves can freeze. If temps are 30ish and I'm comfortable the sun will be warming my bench within 30-60 minutes, I'll spray all the foliage down and leave for work. If temps were colder, I'd probably just leave the plants inside for the day. Hopefully, tomorrow morning is the last time I'll have to think so hard about this
.
penumbra
Imperial Masterpiece
I water the crap out of everything just before dark. It is a commonly accepted procedure that I remember from back at least 50 years. I could not quantify it either.
rockm
Spuds Moyogi
I bring trees in when temperatures are forecast to be 36 and below. I know my microclimate runs a bit colder and a bit warmer than the official forecast. I also look at National Weather Service forecasts--which issue frost and freeze alerts specifically county by county.
