July 7, 2011 | 10:32 AM | By

New climate normals change gardening zones

FILED UNDER: Human Impacts, new normal

If you’re a gardener, listen up. Discovery News reports that one consequence of the new climate normals released by the NOAA’s National Climatic Data Center on July 1st is a new hardiness zones map. For the non-gardeners still with us, the U.S. Department of Agriculture maintains a map of so-called hardiness zones – essentially, areas where different types of plants are likely to thrive. The zones are determined by average winter low temperatures, with each zone being 10ºF warmer as you move southward.

The new climate normals showed that winter minimum temperatures have increased more dramatically than summer high temperatures, with some regions seeing an increase of 2-4ºF over the 1971-2000 climate normals.

So NOAA and USDA are working together to update the hardiness zones map (the current map was released in 1990). Here’s a preliminary version created for the American Public Garden Association.

NOAA

USDA is updating its official map of plant hardiness zones based on the new climate normals released by NOAA on July 1st.


If I’m reading this map correctly, it looks like Cape Cod has moved from Zone 6 to Zone 7. That, alone, might be good news for gardeners and farmers pining for a longer growing season. But, of course, climate change is also altering rainfall patterns and pest ranges. So it’s hard to pin a ‘good’ or ‘bad’ label on the changes overall.