Silverhill Seeds, hardiness

Kenneth Hixson
Sat, 07 Feb 2004 07:53:24 PST
Hi, Members
ConroeJoe wrote
>Yet, Silverhill seeds is quite confident that the Lachenalia species they 
>offer will endure temperatures to 20 F, or lower.  They rate them zone 8
>and are clear and confident in their ratings if you email them.  Perhaps 
>Silverhill has taken time to get seeds from higher elevation materials?  I
do trust 
>their general evaluation of their materials.  
	First, I don't mean this as a criticism, but it appears to me that
Silverhill rates hardiness based on their own experience--exactly what you
want from a catalog, rather than over-optomistic offerings from some other
catalogs.  Some examples:
	Kniphofia rooperi Z9   (Thompson and Morgan lists it as Z7)--I have 
seedlings of this, and they were apparently unhurt by this winter, which I 
believe got to +19F.
	Kniphofia uvaria Z8--the common "red hot poker", and as such far 
hardier than Z8.  The Pfitzer hybrids were raised and selected in Germany, 
for instance.  However, it has been hybridized and selected so I kon't know 
exactly how hardy the species itself is.  

	Zantedeschia aethiopica, Z8--common white calla lily--has been grown
here in Z7 for longer than I've gardened, and there is a selection
(Crowbourogh--sp?) that is supposed to be hardy at least to Z6, possibly to 
Z5 with protection?
	So, my assumption is, although Silverhill rates their offerings
accurately according to their experience, some of them are certainly
hardier.  Silverhill can't be expected to give information they don't
have any experience with.  The challenge for the rest of us is to
find out just how hardy things are, and find hardier individuals of
various species/hybrids, of things which are not reported to be hardy.
To paraphrase Tony Avent, "We need to kill plants at least three times
ourselves, before we know it isn't hardy".  This will take time, and
enough plants available to experiment, and the courage to accept the
inevitable losses.  We then need to share these hardiest individuals
of the various species.  Certainly, there are many such plants we still
have to find.
	Ken  Z7 western Oregon USA

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