ajm55555
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How do you find out a tree was damaged by frost? Wrinkles, color fading on the bark or only in the Spring when it doesn't sprout?
Maximum lowest temperature for Japanese Maples
- Thread starter ajm55555
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AlainK
Imperial Masterpiece
I don't know about "closer to the door", but here in Europe, it was a common sight to see trees painted white up to about 1.50 (five big male feet). In some areas, especially southern Europe (South of France, Spain, Portugal), you can still see some, but it's not about the weather, they're painted with lime milk - or sthg - to prevent fungus and critters attacks.
I couldn't agree more...
leatherback
The Treedeemer
Here I have seen -12 this winter. My maples have healthy shiny buds. In pots, mind you.
Dormancy breaks once temperatures rise above a certain threshold, AFTER the minimum dormancy period has reached, afaik. Similar to seeds; They only germinate if they have had a minimum period of cold. So.. If your tree goes to sleep and you get a warm spell in December, it will not start growing. Yet if the same temps are reached in March, he plant will wake up. That is how I understand it. Day length might interact with this too, but I am not sure.
Dormancy breaks once temperatures rise above a certain threshold, AFTER the minimum dormancy period has reached, afaik. Similar to seeds; They only germinate if they have had a minimum period of cold. So.. If your tree goes to sleep and you get a warm spell in December, it will not start growing. Yet if the same temps are reached in March, he plant will wake up. That is how I understand it. Day length might interact with this too, but I am not sure.
AlainK
Imperial Masterpiece
Do you protect them one way or another, like putting leaves/mulch on the soil?...
You've got way more experience than me. I'm curious though, do you mean the soil temperature was lower or the air temperature?
leatherback
The Treedeemer
Nope. Last night we hit -11C again (ground level temps are right now -12.8c, air temperature -9c according to the nearest official weather station, about 10km away. Having just walked to the backery I can confirm. It is shitty cold.). The plants are frozen solid, just sitting on the pavers. Only the trident has moved into the shed.
Today I will probably put the benches together I started around christmas. It looks like the deep frosts will let up now, so I hope to start putting trees on the benches today again. Larch, beech and lonicera have been on benches since christmas. Junipers have not left their stand untill yesterday (Woodwork needed a new coat of anti-fungus stain).
Don Blackmond, Are your Japanese Maples in pots? What's the lowest temperature that you had? I have 15 japanese Maples in containers outside and we dropped to 7 degrees Fahrenheit in early January 2018. I have a layer of leaves around the containers and a bit on the top. You think the cold killed them?
0soyoung
Imperial Masterpiece
Acer palmatums/shirasawanums are ok down to about 15F (-10C) below which the roots will likely need some protection. In the ground, most varieties are hardy to zone 5 with sun/wind protection (winter desiccation in the killer). Tridents (usually classed as a 'Japanese maple') are not quite as hardy, especially root-wise.
AlainK
Imperial Masterpiece
Correct.
In the ground, -25°C is OK , minus 13 Farenheit.
By the way, once again, this unit of measurement is so stupid : why do you little big country stick to medieval units of measurements inherited from your former master, the King of England ?
Oh, OK, the 2nd amendment, I understand.
Well, I don't, but you don't either, do you?
I'm sure Alexandra will enjoy this song, the rhythm is very similar to a lot of Mediterranean songs, "our" cultural background, though we have our own specificities
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0soyoung
Imperial Masterpiece
NFI - it is just how it is. I 'know' how 72F feels. I know how 40F feels because that is what all the goddamn 'read outs' indicate. I must stop and think: subtract 32, divide by 9, multiply by 5 (okay just divide by 2 is close enough) to say 20C, 5C. But in thermo we always said room temp is 25 mV (Bluetooth is amazing). What is absolute zero (0 Kelvin) in Farenheit? I don't care. It would mean nothing to me. I can remember 273.15, so I just leave it as -40 is 233K.
I can choose km/hr or mi/hr on my car with the press of a button. But seeing that I'm going 100 on the dash just makes me laugh, because I'm calibrated for speed. It is just like 'doing 60' as we say over here. At least my car's steering wheel is on the correct side, right?
I remember there was an attempt to 'go metric' circa 1970. It obviously didn't happen. I recall a big part of the stink was manufacturers having to retool to metric sizes - OMG. Now I must have metric sockets as well as 'English' to get anything done. It is nuts!!!
I have one that was in a shallow plastic basket on the ground in temps at and below 0* F. It's already leafed out and is sitting in front of a lamp. I have three more that were in similar circumstances, and they... may not have survived. It's too early to really tell and they're still green, but I'm not holding out much hope for them unless they surprise me and/or I suddenly get a lot better at not killing cuttings. I suspect the different amounts of snow cover they received, and the difference in cultivar (the two doing fine is a Shishio Hime and unknown green-leaf seedling from Japanese Maples and Evergreens, the other three are red-leaved seedlings) may have something to do with it.
The one that was in a 1-gal pot with no other protection is perfectly fine and I induced leafing with no problems. The big one in the 15-gal pot is showing some dieback, but considering it was a after-season rescue, I brutalized its roots in July/August, and it was at one point turned into an ice sculpture, that's to be expected.
Being as you did more for yours than I did for mine, you should see some better survival rates. I know I'm looking into expanding more into trees that can take our winters with less protection to more thoroughly idiot-proof this; I've read good things about the Amur maple.
By the way, once again, this unit of measurement is so stupid : why do you little big country stick to medieval units of measurements inherited from your former master, the King of England ?
Oh, OK, the 2nd amendment, I understand.
Well, I don't, but you don't either, do you?
Because one unit of measurement really is as good as any other. I use Imperial and metric interchangeably; there's really no advantage to be had with either system unless you're simply bad at using systems of math other than base ten.
Well, that, and it's just so much fun to annoy the rest of the world who insists they're better than us because they're bothered by how we measure things.
The short version on the Second Amendment is that we don't like kings, we just like their units of measurement.
Gustavo Martins
Omono
Correct.
In the ground, -25°C is OK , minus 13 Farenheit.
By the way, once again, this unit of measurement is so stupid : why do you little big country stick to medieval units of measurements inherited from your former master, the King of England ?
Oh, OK, the 2nd amendment, I understand.
Well, I don't, but you don't either, do you?
I'm sure Alexandra will enjoy this song, the rhythm is very similar to a lot of Mediterranean songs, "our" cultural background, though we have our own specificities
Wow. Never would have imagined that would to listen to Amália here!
about the units: it would be nice and easier if everyone spoke the same language, be it F, C or K. But...
I suppose we just like to make it complicated ?
ajm55555
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... once you're used to it, but if you need to deal with some of them at the same time, it can get confusing.
Plus some units made much more sense in the past than now.
The metric system is based on powers of 10 and the temperature has some easy to remember values like 0 and 100.
Different standards are really bad in general. Some would be easier to switch to (weight, length, etc) others more difficult (which side of the road you drive on, plugs, etc) but it would be good if we all used the same ones. (My opinion ;-) )
ajm55555
Chumono
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A classical example of why different systems can be confusing (and costly).
September 30, 1999
(CNN) -- NASA lost a $125 million Mars orbiter because a Lockheed Martin engineering team used English units of measurement while the agency's team used the more conventional metric system for a key spacecraft operation, according to a review finding released Thursday.
September 30, 1999
(CNN) -- NASA lost a $125 million Mars orbiter because a Lockheed Martin engineering team used English units of measurement while the agency's team used the more conventional metric system for a key spacecraft operation, according to a review finding released Thursday.
Gustavo Martins
Omono
That's s why there is an official international system, which is, I believe most use here in Europe (apart from the UK). Metres, Celsius, grams, etc. in science we always need to use these
0soyoung
Imperial Masterpiece
There are two official measurement systems:
- MKS - Meter, Kilogram, Second
- CGS - Centimeter, Gram, Second
... highly pedandic!
Gustavo Martins
Omono
Those are not different systems.
ajm55555
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Exactly!
1 meter = 100 centimeters, ...
That's why the metric system is easy! ;-)
A matter I will concern myself with when I find myself building a Mars probe.
The takeaway from that mistake really isn't that we should all use the Imperial system, it's that we shouldn't forget to put the units of measurement next to our numbers. You'd have run into the same problem if one team assumed everyone was operating on the MKS standard while everyone else was using the CGS standard.
