CIDP - root system, soil and air temperature, soil frost ... - why does it survive in some places but not in others?

[Mazat]

we had a lively discussion last night about why CIDP survives in certain places and not in others ?

about the root system:
if the roots only partially die off after a heavy frost, become mushy, then the whole palm could continue to live even after a heavy frost and full loss of leaves - is this theoretically and practically possible if warm to hot temperatures follow, as is often the case in texas, for example ?
is the whole thing still possible if only a few roots are still intact, say two or three, would that be enough ?

if the soil does not freeze or rarely does CIDP survive in cooler regions ?

what are your experiences ?

[Phoenikakias]

Where did this lively discussion take place? Some web forum?  I can read and understand German btw...

[Mazat]

17 minutes ago, Phoenikakias said:

Where did this lively discussion take place? Some web forum?  I can read and understand German btw...

we met two friends last night, both have already planted out and potted CIDP, one has several Trachycarpus fortunei that are over 50 years old and a large (by local private standards) greenhouse with various exotics grown from seed. The other focuses more on citrus fruits.

In the end we ended up with the CIDP

[Phoenikakias]

If discussion is accompanied with beer and sausages low tones can be held during the debate lol.

[Mazat]

16 minutes ago, Phoenikakias said:

If discussion is accompanied with beer and sausages low tones can be held during the debate lol.

😂,no Konstantinos, these two gentlemen were and are rather conservative in this respect, it remained with coffee and cake 😁

[Phoenikakias]

7 hours ago, Mazat said:

we had a lively discussion last night about why CIDP survives in certain places and not in others ?

about the root system:
if the roots only partially die off after a heavy frost, become mushy, then the whole palm could continue to live even after a heavy frost and full loss of leaves - is this theoretically and practically possible if warm to hot temperatures follow, as is often the case in texas, for example ?
is the whole thing still possible if only a few roots are still intact, say two or three, would that be enough ?

if the soil does not freeze or rarely9 does CIDP survive in cooler regions ?

what are your experiences ?

Admittedly I am not familiar at all with frozen soil. I can only wonder, how roots can die below ground because of  soil frost while meristem above ground still manages to remain alive... But if this just in theory does happen, Phoenix canariensis is amenable to transplant, meaning that it may survive, given that it remains free of any fungal disease.

[UK_Palms]

In all the places where CIDP survives long term, they do not have to deal with any kind of major freeze. This is the ‘be all and end all’ of survival. There are extreme cases of them coming back in Texas and New Mexico, but for most areas that are much wetter, or have cooler growing seasons for recovery, any hard winter freezes will wipe them out. Especially in back to back years.

If your lowest winter minimum on average is below -5C / 23F then you won’t be able to grow them, as every other winter will get colder than that meaning defoliation. Back to back defoliations will wipe them out, as can a single brutal winter that see’s perhaps -9C / 15F followed by a load of rain to rot the crown. This is what wipes out CIDP in the inland regions of England, away from major cities, like London. It has been tried and tested.

You really need to have winters that do not get colder than about -4C / 25F at worst really most years. St James Park in central London is an open exposed park and has had winter minimums of -3C / 26F the past 2 winters, with the absolute lowest being -5C / 23C in December 2010, February 2018 and January 2023. So the critical damage threshold is not reached in that microclimate = survival. If you are having -5C / 23F or lower every year, they won’t survive for you, especially since you will have far lower than that some years.

CIDP also don’t like being wrapped much and a lack of airflow and a lack of sunlight will cause crown rot and a loss of vigour, further weakening the palm. You would need very good airflow and low humidity inside the protection method and even then it is still on borrowed time as the CIDP will outgrow the protection eventually. This is all stuff that has been highlighted in threads on here before, by myself and others. The CIDP’s over here in the UK provide a telling case study on where they survive and what temperatures they survive in cooler, maritime environments.

[Mazat]

On 4/17/2025 at 1:50 PM, UK_Palms said:

In all the places where CIDP survives long term, they do not have to deal with any kind of major freeze. This is the ‘be all and end all’ of survival. There are extreme cases of them coming back in Texas and New Mexico, but for most areas that are much wetter, or have cooler growing seasons for recovery, any hard winter freezes will wipe them out. Especially in back to back years.

If your lowest winter minimum on average is below -5C / 23F then you won’t be able to grow them, as every other winter will get colder than that meaning defoliation. Back to back defoliations will wipe them out, as can a single brutal winter that see’s perhaps -9C / 15F followed by a load of rain to rot the crown. This is what wipes out CIDP in the inland regions of England, away from major cities, like London. It has been tried and tested.

You really need to have winters that do not get colder than about -4C / 25F at worst really most years. St James Park in central London is an open exposed park and has had winter minimums of -3C / 26F the past 2 winters, with the absolute lowest being -5C / 23C in December 2010, February 2018 and January 2023. So the critical damage threshold is not reached in that microclimate = survival. If you are having -5C / 23F or lower every year, they won’t survive for you, especially since you will have far lower than that some years.

CIDP also don’t like being wrapped much and a lack of airflow and a lack of sunlight will cause crown rot and a loss of vigour, further weakening the palm. You would need very good airflow and low humidity inside the protection method and even then it is still on borrowed time as the CIDP will outgrow the protection eventually. This is all stuff that has been highlighted in threads on here before, by myself and others. The CIDP’s over here in the UK provide a telling case study on where they survive and what temperatures they survive in cooler, maritime environments.

thank you very much, Ben, for your explanations and information and the facts about temperatures, so-called threshold values, and if it falls below that, it's good night, so to speak. the idea with the root system came from a friend who cared for CIDP for 8 years and then gave it away because it was too big for him (he is now over 80 years old) to his brother and his son who live near lugano south ticino switzerland and are gardeners.
so it's no good if some of the roots of the entire root system survive in severe frost, which means in this case that the whole plant dies either quickly or more slowly. Unless someone actively protects it as has been described and as we and others have already done near and to the north of us, Germany, Belgium, Poland and other known countries.
with a musa basjoo, one rhizome is enough even if the whole rest is dead after a heavy frost to ensure survival, so to speak, and to live on. it is of course also a completely different species.
we, including myself, were simply not 100 % sure whether this could theoretically be achieved with a CIDP with less unaffected roots. now we have the answer, no.