Re: Iris japonica

My impression is that I. gracilipes is found at higher elevations in Japan
where the summers might be milder.  Is this correct?  If so it should do
fairly well in the Appalachians.

The whole question of summer hardiness as opposed to winter hardiness is a
subject not very often addressed in the North American garden literature,
and not at all inthe British books.  Plants must make enough food during
the day to answer their own metabolic needs  and to get them through the
night (also to have some to store away to invest later).  If the nights are
cool, their metabolic rate goes down, and no problem.  If the nights stay
warm, they may burn more food at night than they can make during the day,
and slowly dwindle away--the classic syndrome for plants that are grown too
far south of their natural range.  This is a pet gripe of mine--that so
much of the garden literature is specific to Britain or the northeastern
US.  The problems (even for those of us in the 'shallow' south) of hot
weather gardeners are discussed in very few specialist books.  And as you
know, Clarence, here in Virginia we have the dual problems of sometimes
hard winters and generally very hot, wet summers.

Best wishes, Bill
___________________
William A. Shear
Department of Biology
Hampden-Sydney College
Hampden-Sydney VA 23943 USA
phone (804) 223-6172
FAX (804) 223-6374
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