New USDA Hardiness map

[mantis]

Haven't seen this posted yet.

http://planthardiness.ars.usda.gov/PHZMWeb/

[bamboothew]

I'm too polite to rant
Gardeners in upstate SC would probably be better served to use the old map

[marcat]

Mantis it took me a few minutes to figure out what thei usda site is all about. I t is the future repesentation after a few years of global warming. I only know my own backyard intamentaly enough to have an opinion but with it they are way off. Most of my county is 9a with the next largest being 8b with Port O'connor being the only part of the county coming close to 9b.They seem to have really screwed it up this time.
MarCat

[bamboothew]

I think the problem may be that the map is stated to be based on "average minimum temps"--if I'm not mistaken the old map was based on either 20 or 30 year absolute minimums, isn't that right? Anyway, if out of 30 years an area's low for 15 of those years is around 20f but the other 15 years the low is 5f, it seems to me the zone should 7, even though the average low would be zone 8. After all, those 5 degree years will kill plants that are only hardy to 15f no matter what the average low is. Plants don't care about average lows

That map shows my area as zone 8 but we get single digit cold several times a decade. North of me to the state line is mountainous with single digits every winter and it is shown in zone 8. Marcat is right--seems like they really messed it up

[dependable]

Yes, The map shows me correctly in 7a, yet if we have a sub-zero event every decade or so, it affects bamboo growers (and a lot of shrubs and trees). In landscape land, I usually sell zone 6 plants or hardier, as I am expected to warranty them for at least a year.