Article 22909 of rec.gardens:
Path: samba.oit.unc.edu!concert!news-feed-2.peachnet.edu!darwin.sura.net!howland.reston.ans.net!spool.mu.edu!uwm.edu!rutgers!uwvax!astroatc!nicmad!nuntius
From: nicmad!klebba%astroatc.uucp@spool.cs.wisc.edu (Bob Klebba)
Newsgroups: rec.gardens
Subject: Re: USDA Hardiness Zones Digitized?
Message-ID: <1993Sep22.050040.13001@nicmad.uucp>
Date: 22 Sep 93 05:00:40 GMT
References: <27fp5s$m1h@vixen.cso.uiuc.edu> <CDp64n.902@cen.ex.ac.uk>
Sender: usenet@nicmad.uucp
Organization: Nicolet Instrument Corporation
Lines: 51
Nntp-Posting-Host: mac1_00
X-Useragent: Nuntius v1.1



In article <CDp64n.902@cen.ex.ac.uk> A.F.Kettle, afkettle@cen.ex.ac.uk
writes:
>Is a 'hardiness zone' the same as I have been seeing in various US
>messages eg 'I'm in zone 5'?
>
>It looks like a fine bit of shorthand, but the trouble with all
>shorthand is that it you don't know what it means then its no use.
>
>Could someone post a brief summary of what the climate is like in 
>these zones - or if that would take too long, then just tell me
>what zone we are on this side of the pond!
>
>Thanks, Anna ;-)

There are two "hardiness zone" maps of the US.  One done by the USDA and
the other by the Arnold Arboretum.  There is also a third for the western
US which has hundreds of microclimates, but I think the majority of
Americans use the USDA map.  I grew up with the USDA map and can't seem
to reckon with the Arnold system.

In any case the hardiness numberings go by winter cold.  Plants also get
killed by lack of moisture or too much summer heat, so the hardiness
rating is just a guideline.  I use it mostly for woody perennials.  The
herbaceous perennials survive well when we have snow cover all winter and
get killed when the winters are warm.  The zone definitions look
something like:
	1	below -50F	(way cold)
	2	-50 to -40F	(most of Canada, but not where most Canadians are)
	3	-40 to -30F	(where Centrigrade and Fahrenheit meet)
	4	-30 to -20F	(where I live!)
	5	-20 to -10F	(where people can grow lots more plants than I can)
	6	-10 to 0F	(pecan trees)
	7	0 to 10F	(azaleas galore)
	8	10 to 20F	(yea, but it's hot in the summer)
	9	20 to 30F	(growing apples is questionable, not cold enough)
	10	30 to 40F	(I can see the palm fronds swaying)

To give you an idea of my climate:  I'm at 43 deg. N (same as Barcelona),
first frost is 25 September, last 10 May.  We get about 3" precipitation
per month (in normal years) evenly distributed throughout the year.  It's
too cold for peaches, most pears, all Mediterranean grapes, sweet
cherries.  Nevertheless there is still a lot that can be grown here.   Of
course, the lakes freeze over in winter and people drive on them, but I'm
sure you already knew that.

Bob Klebba
Madison, Wisconsin, USDA zone 4
Inet: nicmad!klebba%astroatc.uucp@spool.cs.wisc.edu
"Feed the soil, not the plant"


