asacomm

In addition to D.Orinoco and D.Brazilian, Rajapuri and Williams hybrid finally
died even with winter protections, but Cardaba survived. All of them were TC
plants except Cardaba which was from pup.

Here is considered to be in zone 9b although there were 2 nights of 25F.
But all TC plants could not overwinter despite pup of Cardaba survived.
TC plants and pups should be DNA wise exactly the same, but it seems to me
that something is different in cold hardiness as pups have experienced the
cold winter, while TC plant faced their first winter. That might make a difference
in cold hardiness.