Connecticut’s new planting zones

The USDA just released a new plant hardiness zone map. Plant hardiness zones are listed on plant tags to communicate the regions in which plant should survive without extra winter protection.

Many will find their zone has changed by a half – mine went from zone 6a to zone 6b, slightly warmer.


Will this alter how I garden or what I plant? No. The map does not take elevation and cover-, slope-, or hardscape-related issues into consideration. Only eyes and experience can do this. I know my property. Plants, shrubs and trees listed as borderline in zone 6 may not survive tough winters without coddling (this means extra winter protection and extra work). If I must have a plant that is borderline in zone 6, I do so with the full knowledge that coddling/extra work will be part of my regular gardening routine.

This is exactly what the USDA recommends on their Maps & Gardening page.

The new map considers 30 years of climate data – a longer period than the 15 or so years previously used and used in other plant hardiness zone maps. More about how the new zone map was created is on the USDA’s What’s New page.

The new map is more interactive than previously. After choosing to view by State, Region, or Nationally, and choosing a size (try Standard then move on to larger versions), you can preview, open or save your map choice.  If you start here, and type in your zip code your zone will pop up under your zip.  Or, for a closer-up view, click on the Interactive Map tab and type your zip code. In the interactive map you can activate a satellite image that shows up under the zone colors. If you increase the transparency of the zone color layer it’s easier to locate your property on the satellite image.

This is particularly useful when trying to determine planting zones in areas near zone borders. For instance, my property, listed as zone 6a in the older USDA map and in the Arbor Day Hardiness Zone Map, is now located very close to the edge of zone 6a in south-central Connecticut but is newly listed in zone 6b.

Follow the various links above and play with the features, but don’t forget that we still must garden thoughtfully. Hardiness zones are guides. Gardeners with the time, experience and where-with-all to push a hardiness zone – say by planting a zone 7 perennial in a zone 6 garden – can be quite successful. Gardeners looking for less maintenance and fuss should stick to their zone or acknowledge that a perennial listed hardy in a warmer zone should be planted as an annual or overwintered with protection.

Digiprove sealCopyright secured by Digiprove © 2012 Joene Hendry

8 comments for “Connecticut’s new planting zones

  1. January 26, 2012 at 10:49 pm

    This is great — a long overdue update from the USDA. It has taken me several years to get to know my own yard and its exposure and sun patterns and prevailing breezes and damp spots. All those variables are more important, as you so clearly point out, than just the average temps that hardiness zones are based on. But the new map is a big improvement!

    • joenesgarden
      January 26, 2012 at 11:56 pm

      Agreed, Laurrie, especially for new gardeners.

  2. January 27, 2012 at 6:46 am

    Hi Joene, Not a big fan of these maps, old or new. As with so much in gardening, I think you learn most of the important stuff from other gardeners, visiting their yards and seeing what grows, what they do and when they do it. I was a book gardener for years, and didn’t know very much until I started making friends with knowledgeable gardeners.

    • joenesgarden
      January 27, 2012 at 12:29 pm

      Cyndy, I agree that the best gardening knowledge comes from getting ones hands in the dirt and learning from experienced gardeners. Still, for the novice, hardiness zone maps narrow plant selections to those that should grow. In other words, zone guides may keep a novice gardener from planting a zone 9 hardy fruit tree in a container and expecting it to survive outdoors during zone 6 winters, thus minimizing discouraging and expensive gardening oops.

  3. January 28, 2012 at 8:53 am

    Joene, I love the new interactive map. I’m still a zone 6b but 7a is creeping close.

    • joenesgarden
      January 28, 2012 at 11:23 am

      Debbie, I think the map is useful for new gardeners just beginning to understand what hardiness zones mean. It will also be very helpful to gardeners facing a move and garden and landscape designers who work in many different locations.

  4. January 29, 2012 at 4:25 pm

    Joene, I was just looking at the new hardiness zones for Maine, and it brought home your point about knowing your own garden conditions. On the new map, my town has been moved from the boundary of zones 4b and 5a firmly into 5b. But the low temperature for zone 5b is -15F, and I saw overnight lows of -20F several times while I was in Maine over the holidays.

    I don’t know if you’ve seen the Versatile Blogger award going around (or perhaps have already been so honored). Anyway, I’ve named you as one of my “versatile bloggers.” You can learn more here:

    No Pressure on this; I am not offended at all if people choose to ignore these awards. -Jean

    • joenesgarden
      January 29, 2012 at 9:59 pm

      Jean, I think all seasoned gardeners understand zone map recommendations are no substitute for knowing your property, as your experience with temperature extremes in your Maine garden illustrates.

      I’m honored you named me as one of your Versatile Bloggers. I would participate if not for the sharing rules … thanks anyway.

      I hope your ‘new zone 5b garden survives its 4b/5a temps.

Leave a Reply

%d bloggers like this: