This is great; I thought they’d released a newer map since then, though. No, the arbor day foundation did a revised zone map in 2006, although one hopes the newer project would be more detailed. http://www.arborday.org/media/zones.cfm

I hadn’t heard about this but I, too, am curious to see what changes are made.

The major ruckus right now about the zone maps is that the ArborDay revision used a relatively short number of (recent) years to calculate their zones. There are a lot of complaints amongst those who do that kind of thing who say it’s statistically not enough of a timespan to be usable because it’s highlighting a recent trend that may or may not continue.

Global warming is pretty much dead-center of the debate. Is it a trend that will reverse or be affected by other factors eventually? There’s the rub.

My God! They moved me a whole zone! Looks like my entire state(Ohio) is now zone 6!
The horror!!!!!

@TropicanaRoses: zone and planting date don’t correlate. Zone tells you which perennials will overwinter. It’s not a timing thing, so much as whether or not you can plan on something being there next year. So, I’m zone 5 but I’m growing zone 6 artichokes (which I think is as hardy as they get). That means unless we have an unseasonably warm winter, they’ll probably be dead next year so I have to either provide lots of frost protection and hope for the best, or I have to treat them like an annual. If I were zone 6, I could just stick them in the ground and expect them to live out their life span. If you’re only growing annuals, or perennials that you treat as annuals, you don’t need to pay attention to your zone at all.

(blush) Sorry. I guess I have more to learn than I thought!

Not to be ugly or anything, but I guess you’re right about that, I don’t know the people on here, and they don’t know me, and they have all been through this, so it is easier than talking to someone locally that knows gardening, and then having them correct you with that superior tone! :) I also noticed that people on here are more tolerant of others stupidity, ignorance, whatever you wish to call it. Thanks for the “Cheer me up”. :D

I was a bit more cautious out here with our high winds. We do have some clear plastic to cover our boxes with, should the temps warrant it, but I tried very hard (I am new at this if you hadn’t guessed!),to make sure that I didn’t plant anything sooner than it was supposed to be except for my roses. I monitor the night time temps very closely, and cover my roses and things that I am hardening off if I think there is the least chance of frost. I did forget one night, and my climbing blaze has not been doing well ever since. I keep wondering if I should prune off the areas of the plant that are in bad shape, because I have a theory. I think that the parts that were injured are sucking all of the plants energy as it tries to keep them alive. I think that if I cut off the bad stuff, that will force it to produce more leaves. I wish I could find out if that is right, but there are so many varying opinions on pruning, that I am confused. Well. Where did all of that come from? End post! :)

I was interested to see the new GIS component (I am a GIS analyst) but did not find anything in a quick jaunt around the site. I also find their map format a bit surprising; for instance, it looks like there are county labels on the map (or on the original anyway) but they are of course too small to read at that scale. At least one zoom level is allowed, but really, a hyperlinked map is not terribly sophisticated in today’s age. It is a relatively simple thing to put together a simple web mapping application or embeddable that would allow more detail and control and less “noise”. There is a vague paragraph about the map being “computer generated” based on average annual minimum temperature data; surely this means the zones were modeled using a GIS. Why not allow access to that data?

I have totally highjacked this post. Sorry. I am going to move this one over to the Roses group.

From what I can tell it is still coming. This is the latest article I could find about it. And it is dated April 28, 2009. More in depth articles with more details all refer to it as still on the way, promising GIS compatibility too. I would think if it were out it would be on the National Arboretum’s page somewhere. But all I can find there is the 2003 web version of the 1990 map (that you linked above, and that the articles link to).

Does anyone know how the UK zones, as used by the RHS (H1 – H4) correspond to the USDA zones? If I’m going to be playing in Folia more I need to get my head around it the whole thing :-) especially as many of the American charts I’ve seen quote temps in Fahrenheit which is completely foreign to me…

@ceae Thanks for that! I combined that with my book and I think I’ve nailed it. Just in case anyone else needs it:

H1 = 9
H2 = 8a
H3 = 7b
H4 = 7a
H4-5 = 6b
H5 = 6a