"Franz Heymann" wrote in message ...
"IntarsiaCo" wrote in message
...
It is *not* hardy. Your -8 deg
C is a load of codswallop. Minimum temperature +5 deg C (41 deg F),
according to the RHS Encyclopedia

S. purpurea ssp. purpurea (the northern form of S. purpurea) is hardy to
well
below -15F/-26C; the RHS Encyclopedia is in error.

The RHS Encyclopedia does not mention S. purpurea ssp purpurea.
Neither did the OP and neither did I.
I have never known the RHS Encyclopedia to be as far wrong as this!


The OP didn't mention S purp. purp directly, but he did mention that
it was a bog dweller in N America/Canada, which is where S purp purp
grows.

I have one of these, along with a S flava hybrid, Darlingtonia and
Dionaea. All of them grow outside and all have proved to be frost
hardy - to a greater or lesser degree. The Dionaea suffered the most
with a few plants succumbing, but the others are postively thriving.

Alastair

"IntarsiaCo" wrote in message
...

The RHS Encyclopedia does not mention S. purpurea ssp purpurea.
Neither did the OP and neither did I.
I have never known the RHS Encyclopedia to be as far wrong as this!


They probably don't mention the other 4 or 5 subspecies either, but
nonetheless, S. purpurea is found in northern New England and into Canada
where
temperatures dip well below -10F. They should correct the entry as it is
misleading. The northern subspecies is not easy to cultivate and requires
a
cold winter dormancy. The southern subspecies range north to New Jersey
and
will also experience temperatures below 0F. The largest populations are
near
Mobile, Alabama where temperatures at this time of year easily go below
20F. I
doubt that they will prove effective in capturing slugs.

I would suggest that since you found the mistake in the RHS Encyclopedia,
you might get in touch with them, as it does seem to be a real gaffer.

Franz