Marumi Kumquat cold hardiness ?

[tedburn]

Who can tell me about coldhardiness of Marumi in ground ? Some stores talk about 0° F to survive ? I can' t believe this.
How long takes the fruit to ripe from bloom ?
Thanks Frank

[poncirusguy]

very few if any places use Poncirus trifoliata or flying dragon for rootstock.  The use of any other rootstock will lessen the cold tolerance to +15F.  Therefore the quick answer is NO.

[tedburn]

Thanks Poncirusguy for your answer.
What dou you estimate the coldhardiness of Marumi on Poncirus or FD In °F, if the plant is not to young and in good shape and not to much freeze days in a row ?

[poncirusguy]

The California citrus breeding program lists the Marumi kumquat to be hardy to 0f for a short period of time when it is fully hardened for winter.  They must be on Flying dragon or Poncirus trifoliata.  I have no experiences with the Marumi cultivar.

[tedburn]

Thank s very much, that sound s very interesting, so Marumi could be a candidate for planting in ground even in my zone 7, as companion of my Kerajis, Nippon Orangequat, Bloomsweet and others.
Do you have a link of this forum or list where this is noted, to see also what they note fir other varieties. Due to the fact that citrus hardiness is not only depending on one factor, it is interesting to take into
account different sources where coldhardiness is described.

[poncirusguy]

I have not been able to find the link.  Ty-Ty nursery states that cold hardiness but there's is grafted to 15F minimum rootstock and there tree would die.  I will keep looking

[poncirusguy]

Found it  citruspages.free.fr/kumquats.php#marumi  It has been revised and it no longer ofers cold tolerances anymore.

[tedburn]

Sept 6, 2023 21:35:22 GMT -5 poncirusguy said:

Found it  citruspages.free.fr/kumquats.php#marumi  It has been revised and it no longer ofers cold tolerances anymore.

Thank you, yes citruspages is a very good source of information, didn't know that they also showed cold hardiness - bad that they don ' t show it anymore, even as an indication. Though it is difficult to indicate cold tolerance due to such a lot of parameters which influence cold tolerance.