Nach dem stärkeren Frost sind es jetzt -1°C und ganz leichter Regen.
Strassen und Wege sind eine einzige Eisfläche.
Knochenbrüche bei Fußgängern sind vorprogrammiert.

Zitat von Sascha im Beitrag #285

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Hallo Matthias, auch wochenlanger Dauerfrost schadet den Yuccas in der Regel nicht - es sei denn die
jeweilige Frosttoleranz der Art und des Individuums wurden dabei unterschritten, da nutzt auch ein
zwischenzeitiges "auftauen" nichts. Das auf und ab ist eher kontraproduktiv.

LG
Sascha

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Zitat von willi pürzelmayer im Beitrag #275

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Hallo Mathias, ich wünsche dir und deinen Pflanzen alles gute und hoffe , dass du keine gröberen Ausfälle hast. Ich möchte nur noch Pflanzen aus deiner Produktion beziehen da die mit Sicherheit bei mir gedeihen würden, so hart wie die sein müssen ,-)
Hie im Wiener Becken blieb es einstellig, eigenartig da es rundherum viel kälter war.
LG Willi

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...also ich bin der Ansicht, dass ein Auftauen über Tag eher hilfreich ist. Meine Faxos bspw. sind umbaut und bei Sonnenschein über Tag
geht es trotz eisiger Temperaturen innerhalb des Schutzes in den Plusbereich. Die anderen Stammyuccas bei mir müssen so da durch aber
konsequenterweise müsste ich auch Y. linearifolia umbauen. Hier mal ein Zitat von Robert Pitman zum Thema:

Zitat von Tim Behan im Beitrag Yucca faxoniana - Erfahrungen und Verbreitung

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Robert,

That's a beautiful faxoniana!!


More regarding hardiness of Y. Faxoniana from Robert Pitman:

"I was reading with interest the recent comments about low temperatures
in Colorado and New Mexico. This is a subject I feel more qualified to talk
about than the deep details of taxonomy. I have done more research and study
in climate and plant adaptation to cold temperatures than in anything else.
First, a few comments to help those who have not intensely studied
climate or plant adaptation
Low temperature readings can often be deceiving. For example, a
temperature of -20F (-29C) may damage or kill
a plant in one area while the same temperature
may do nothing to the same species in another area. Or -20F
might damage a plant one year and another year the same plant may
go through -20F in the same location without any damage.

Let me use a real life example: In 1991 I was traveling through northern
New Mexico and in Farmington (USDA zone 6) I saw an office complex with
numerous dead Yucca faxoniana. This surprised me because that location was a
full zone colder than where Y. faxoniana normally survives. The Y. faxoniana
were well established and had been there for several years. Most of the
Rocky Mountain states had experienced a very brutal cold wave the previous
December. The low for that winter in Farmington had been -16F (-27C). That
temperature is nothing terribly unusual for northern New Mexico but the cold
wave lasted a long time and was very intense. Obviously the Yucca faxoniana
had managed to get through several mild winters in Farmington until a cold
winter killed them off.
Also on the same trip I noticed two good sized Yucca faxoniana at a
restaurant in Cuba, NM. They looked like they were recently planted. Cuba
is higher elevation than Farmington and is mapped in colder USDA zone 5. I
wondered how long these
Y. faxoniana would survive there. Two years later while traveling there
again, I noticed the Yucca faxoniana at Cuba in zone 5 had some marginal leaf
burn but were still very much alive. Upon returning home, I looked up Cuba's
weather records and saw that it had fallen to -15F (-26C) the previous winter.
The question is, how could temperatures only one degree apart completely
kill a species in one location and cause only insignificant damage in
another. The answer lies in the intensity and duration of the cold. At
Farmington the cold wave that killed Yucca faxoniana was a week long and the
daytime temperatures hovered around
10F (-12C). At Cuba the cold spell was brief and the daytime high was 33F
(+1C). So that explains how low temperatures readings only 1 degree apart
can produce totally different results.
I know of many examples just like this. (last week I mentioned that
Ferocactus acanthodes had survived -18F in 1988 in Caliente, NV and two years
later the same plant was killed outright by -19F). And since we were talking
about Colorado, I know of many, many plants which survive -35F in Ft. Collins
which would be dead as a door nail at -35F in Minnesota.
What really damages a plant is COLD INTENSITY. We really do not have a
good way to measure cold intensity. Cold intensity cannot be measured by
simple low temperature readings. But, if one is willing to do some research
there are a few indicators. Using weather records one can see what the daily
high temperature was, along with the daily low temperature. Also one can see
how long the cold lasted, whether it was a three day episode or whether it
lasted a week.
The greatest tendency is to over simplify. We would like to believe
that -20 is -20 is -20. The cold is far more intense on a day where the low
temperature is -20F and the daytime high is only 0F than on a day where the
low is -20F but the high is +20F. All the research and study I have done
indicates that the daily high temperature during a cold wave is as important
to know as the daily low, although this is rarely reported.
One of my first introductions to this concept came while reading an
issue of Desert Plants from around 1978. The article stated that Saguaro
Cactus (Carnegia) is limited in it's natural distribution to areas where the
daily high temperature has never failed to rise above freezing, even on the
coldest day ever.
This theory was pretty much confirmed in my mind when I observed in Las Vegas
in 1991 that about half of the Saguaros there had died from the previous
winter. The low for that cold wave was 11F (-12C) but more importantly the
high for at least two days was at 33F (+1C), right near the threshold of
survival. The fact that about half the Saguaros lived and half died could be
attributed to microclimate, health of the individual plant etc. There was
one other place in Nevada where two Saguaros survived a low of 4F (-15C) but
where the daily high was 35F (+2C). It seems with Saguaro that the day time
temperature of a cold wave is more critical than how cold it may get at night
for the low.
All plants have a temperature threshold of damage and a temperature
threshold of death. Unfortunately, for most plants it is not as well known
as the threshold is for Saguaro.
Because all that is usually reported for cold tolerance is a single low
temperature reading, we are often left to guess. If this cactus survived -20
in one area will it survive -20 in my garden? Of course one of the greatest
joys we all have is experimenting and discovering what grows where.
I am well aware of the many other factors involved with winter survival
( winter wetness, snow cover etc.) but don't have time to discuss those now.
By the way, a really good site for daily weather records of the western
states is at
climate.usu.edu/free/ This site has all the weather data for hundreds of
weather stations for the last 60 years or more."

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Hallo miteinander,

da ich noch einige Meter Jute auf dem Ballen habe, hat die ovati mehrere Lagen einfach übergestülpt bekommen. Sodass ca. überall 4 Lagen Jute darüber ausgebreitet war. Das überraschende für mich war, dass trotz -12 unter der Jute nicht eimal -3 erreicht wurden. Dazu muss ich noch sagen, dass ich die Jute noch nicht einmal richtig dicht am Boden hatte. Allerdings steht mein großes Schutzdach darüber. Dennoch werden da mind. -9 eingedrungen sein.

Mir ist die Wirkung von Jute wohlbekannt, dass diese jedoch so große Isolierung schafft, war mir bis gestern nicht bekannt.



Auch bei uns sollen die Nächte auf Montag und Dienstag wieder die Gefahr von strengem Frost bringen können. Es ist eben mal wieder Winter. Der Verlauf dieses Winters ist sehr viel anders als in den vergangenen 3 Jahren. Dies bahnte sich bereits mit einer schnellen Ausbreitung einer Schneedecke in großen Teilen in Sibiriens im November an. Und diese Schneedecke ist sehr dynamisch bis Ende 2016 in Polen angekommen. Durch die viel stärkere Westdrift in den vergangenen Wintern wurde dies Schneedecke immer wieder weit bis Russland rein zum Abtauen gebracht. Auf jeden Fall ein spannender Winter, auch wenn ihn von uns keiner so richtig braucht. Die Skifahrergilde mag bitte Nachsicht haben.

Hallo Sascha,

da bin ich komplett anderer Meinung. Wenn das Meristemgewebe dauerhaft durchfriert ist Ende mit Schönschreiben.

Die Aussagen von Robert Pitman beruhen doch zum Einen auf Beobachtungen, zum Anderen auf
Differenzierungen. Eine Tiefsttemparatur ist in dem einem Fall mortal, in einem anderen Fall eben nicht.
Es kommt auf die Dauer der Minustemparaturen an und ob die Pflanzen über Tag wieder auftauen können.

bin jetzt in österreich und freitag/samstag in schärding -20°,in toscana -3° und adria -1°.
nur zur vergleich was alpen für kälte abhalten.

lg
johan

Hallo Reinhard

wie tief sank das Thermometer heute bei Dir? Noch im Rahmen geblieben?
@Reinhard

LG Matthias

Wien Umgebung momentan um -13°. Morgen soll es dann langsam wärmer werden.
LG Willi

Zitat von Matthias im Beitrag #297

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Hallo Reinhard

wie tief sank das Thermometer heute bei Dir? Noch im Rahmen geblieben?
@Reinhard

LG Matthias

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