Remember the big news about the USDA rejecting the revised zone map it commissioned the American Hort Society to do for it? And then it was tweaked a bit and released by the Arbor Day Foundation. And of course the USDA denied that the new map was rejected for political reasons.
Well, the USDA's just about ready to release a revision they DO approve of, as reported in the Daily Climate.
In that article Tony Avent is quoted criticizing the rejected map because it moved the zones too far southward – apparently moving Chicago from Zone 5b to Zone 6. Says Avent: “In 2004 Chicago had a -21º
winter. If Chicago gardeners had planted zone 6 plants,
they would all have failed. When plants die customers give up
gardening, and that’s the nursery business’s worst nightmare.”
And another expert backs up that opinion:
Michael Dosmann, curator of living collections at Harvard University’s Arnold Arboretum
in Boston and an advisor on the USDA revision, expects that the new map
will be much more credible than either the AHS version or the current
1990 map. “I think we can have a lot of faith in it.
Let's hope so.