Wednesday, January 25, 2012

I Feel The Earth Move Under My Feet

I heard Carole King's voice singing "I feel the earth move under my feet" when I saw today that the USDA had finally released an update to their US Plant Hardiness Zone chart.

Somehow, without moving to a new house my garden has become a zone warmer.  What was once just a Zone 9A garden is now a wonderful 9B garden.  What does this mean for me personally?  It means that I now have access to 2,023 plants at Annie's Annuals that will grow in my backyard.  Yesterday there were only 1,925 plants I could grow.  So there's that. 

This change has been a long time coming (22 years since the last update).  In the meantime, most people who care about this sort of thing had already adjusted their zones in their own mind or switched over to a different system such as the Sunset Western Garden zones which looks at your location's overall climate including summer highs, length of the growing season, rainfall and humidity and not just winter lows like the USDA chart does.   

I don't really see this making a huge difference in the way I garden.  To me, it's more of an acknowledgement on the part of the USDA that their previous map was so 90's and was overdue for a makeover.  It might also say something about global climate change . . . but I'll let the USDA speak for itself on that "hot" button topic. 

I'd love to hear if anyone had a more signficant change in their official zone rating and what that means to them as a gardener, if anything.


  1. I'm right on the line, not sure if it thinks I'm now 8b. But, seeing other 8b gardens, I know mine is a true 8a, so I'll stick with that!

  2. Holley, did you try looking it up by zip code? Not that it truly matters because it sounds like you know your true zone already, but that might help narrow it down for you if you're curious.

  3. I'm still a 7A. I usually stick with plants that are hardy to at least a zone 5 but this year I'm putting in a few shrubs that are only hardy to zone 7. We'll just have to see how they do.

  4. We used to be considered 7b/8a, and we have had 7b winters before, but usually 8a is pretty right on (which is what the zip code look-up revealed). This year, however, it looks like we are having a 10a winter, go figure. Just when you think you've got it all figured out, it changes. Keeps us on our toes, I reckon.

  5. Chad, I'm reminded of the joke about the time a surveyor mapping the Maine-New Hampshire border encountered a farmer and explained that the new survey put his farm in New Hampshire instead of Maine. The farmer's reply: "Thank God; I couldn't have stood another one of those Maine winters!" Seriously, I'm taking the new zones with a large grain of salt. My part of Maine has now moved from the zone 4b/5a border to zone 5b -- but the minimum temperature in zone 5b is -15F; and even in this warm winter, I've already had at least three mornings with temperatures colder than that. The zones are broad brushstrokes; microclimates matter. -Jean