Re: USDA vs. Sunset zones
- To: Multiple recipients of list <firstname.lastname@example.org>
- Subject: Re: USDA vs. Sunset zones
- From: "Jeff and Carolyn Walters" <email@example.com>
- Date: Sat, 8 Feb 1997 16:32:59 -0700 (MST)
In response to a comment by Jefrie Jenkins reagrding the horticultural zone
in which Schreiner's, Cooley's, and Aitken's Gardens are located, Julie
Allen wrote (8 Feb 97):
> I was wondering about this. Zone 6, USDA zones, has winter temps of 0 F
> -10 F, and I don't think Shcreiner's gets this cold, or does it? Here in
> zone 6, USDA zone, in middle Tennessee, our expected frost-free period is
> about April 15 to Oct 15. The Sunset Western Garden Book has its own set
> zones. I noticed that the Zone finder on the Internet lists both sets of
> zones. Gigi, are you lurking out there? Or Rick, are we talking about
> different sets of zones?
Yes, it is a matter of two different systems of defining zones. The area in
question (lower Willamette Valley and Vancouver, WA) is in USDA Zone 8,
which is defined by expected low winter temperatures in the range of 10 to
20 F. The same area is labeled Zone 6 in the Sunset Western Garden Book.
Sunset uses more factors than low temperatures in defining its zones, as it
specifically notes that some areas of Zone 6 may have lower winter
temperatures than in Zone 5.
When mentioning zones on the list, it is probably preferable to refer to
the USDA zones, as Sunset's system only covers the western states.
Jeff Walters in northern Utah (USDA Zone 4; Sunset Zone 2)
"This is the Place" - Utah Pioneer Sesquicentennial: 1847-1997