Plant hardiness zone map on DG

I am confused (but not concerned, because that is frequently a normal state for me) about the zone map that DG is using. When I Google, I consistently come up with a very different published current Zone Map. I did a brief forum search here and notice that this was discussed last year when the change was made. http://davesgarden.com/forums/t/438055/ And there were quite a few questions raised then, but I didn't see a definitive answer.

Has the issure ever been resolved? I have never seen this version of the map anywhere else, so I wonder, if this is the new one and over a year old, why it is not being used everywhere else by now. Can you comment on where things are with the USDA? And which map is most current? I am really suspicious about cold, cold Michigan being lumped in with some of the z6 states that hardly ever see snow and never get sub-zero temps.
Judy

I think there's still a fair amount of contention and debate over the new (still-draft) map. I'd vote to change it back to the older, accepted one until the USDA and/or AHS (or whoever makes the final decision) determines if it's a go or no-go.

OK, so we should just ignore it. That will be easy to do, because it looks so strange to me. They will have to convice some of us that have been gardening a long time. I guess I am getting to be an old dog, but I would bet anything that the map-makers don't live in the north. Thanks, Terry.

Well, I am very supportive of the new map because it is the first zone map that was produced entirely electronically using raw climate data for the past many decades. Average lows were computed and the graph was literally generated completely automatic.

It's highly unlikely that any of it would be inaccurate. In this respect, I prefer it and hope it takes hold.

But, on the other hand, maybe holding off on it until it is officially accepted might be a better idea...

dave

My zone goes from a 5b on the old map to a 6a on the new one. I'll take it!

Here is a quote from a person that is involved with the USDA hardiness zone process:

I found when looking at the new map, that I couldn't get a close enough to look to see just which zone Ottawa is in.

Ann

PS (I looked it up last week after I took a peek at the list of members from Ottawa who listed their zones as anywhere from 2b-5b).

If anyone knows where a good sharp clear copy of the old USDA map is, I'll be happy to change. The one that the USDA publishes on their website is very fuzzy. It's nearly impossible to tell what counties are which.

dave

Google ottawa hardiness zone, for some interesting discusions.

John

How 'bout this?

Clickable Map of US States - Climate Page
http://www.cdc.noaa.gov/USclimate/states.fast.html

~* Robin

That site has some interesting information. I learned that the max temp from 1961 to 1990 near me was 104 F. I would have thought it would be higher since average temp for this time of year are around 90 F. I also learned that the min temp for that range was -18 F. That is pretty chilly and a reason that I reluctant to plant things that are only hardy to zone 7.

Unfortunately I did not see a map with the USDA Zones.

- Brent

I guess it's true: A good map is hard to find.

Ha, Terry! :)

For the Western part of the USA and Canada, I much prefer the Sunset garden zones which take into account not only average winter lows but summer highs, number of gardening days and record high temperatures. There are also a significant increase in the number of zones including specific ones for Alaska and Hawaii. I wish the USDA would get together with Sunset and start speaking the same language. Dotti

Terry or Dave,

I found out that I have a pdf interactive file of an USDA Plant Hardiness Zone Map saved on my computer. It is 5,703 KB; from March 2003. I don't remember where I got it from... too long ago.

If you want I can send a copy to either of you so you can examine it.

Tell me where I can send it to.

~* Robin

The copy you have is the unapproved AHS copy, Robin. We're looking for the old one from 1990.

dave

Oh, ok then.

Edited to ask if this is the one you're talking about: The 2003 US National Arboretum "Web Version" of the USDA Plant Hardiness Zone Map USDA Miscellaneous Publication No. 1475, Issued January 1990 http://www.usna.usda.gov/Hardzone/ushzmap.html

~* Robin

This message was edited Jul 26, 2005 11:12 PM

Yes, that's the "official" map. If we could find it in hi resolution or PDF, that would be great.

dave

Well at least I can help some New Yorkers:

Average Last Spring Frost Date for NY - Cornell Gardening Resources
http://www.cce.cornell.edu/programs/hort/gardening/weather/sprfrost.html

USDA Hardiness Zones for New York - Cornell Gardening Resources
http://www.cce.cornell.edu/programs/hort/gardening/weather/zones.html

Average First Fall Frost Date for NY - Cornell Gardening Resources
http://www.cce.cornell.edu/programs/hort/gardening/weather/falfrost.html

Average Freeze-Free Season For NY - Cornell Gardening Resources
http://www.cce.cornell.edu/programs/hort/gardening/weather/frezfree.html

CCE in Your Community for New York:
http://www.cce.cornell.edu/about/inyourcommunity.php

Find Your State's CCE Service Offices
http://roundrobin2001.0catch.com/extensions.html

Scroll down the page for more info, like This: National Frost Dates by City and State; Fall Planting Dates for Vegetables by Average Spring Frost Date for your Area; etc.

~* Robin

PS: Craig Cramer is a member of Dave's. eupatorium http://www.gardening.cornell.edu/cdc/

Hey Robin, they didn't give the last SNOW dates! lol Great info for me, and I am still zone 5a. The AHS map had bumped me up a full zone and that was just ridiculous.