USDA:
Compared to the 1990 version, zone boundaries in this edition of the map have shifted in many areas. The new map is generally one 5-degree Fahrenheit half-zone warmer than the previous map throughout much of the United States. This is mostly a result of using temperature data from a longer and more recent time period; the new map uses data measured at weather stations during the 30-year period 1976-2005. In contrast, the 1990 map was based on temperature data from only a 13-year period of 1974-1986.
Mary Ammond says
I would like to start my first veggie and fruit garden when do I plant?
jhofley says
Mary-
That depends on a lot…seeds vs. seedling plants, type of plant, location, etc. As for seeds, you can consult the back of each packet for instructions. As for seedling plants, as the experts at the garden center where you buy your plants. Some cool-weather crops can be started early where others need the soil to warm more. Good luck and happy growing!