Last Frost Dates

March 12, 2002


Provided by: USDA/ National Arboretum
Summary authors & editors: Jim Foster

Though in places winter is still is packing a punch, with the gradually longer days and sometimes warmer weather of early March, it won't be long before outdoor activities and chores replace the ones indoors. The USDA uses a frost map (date of last frost) that should give you an idea of when it's ok to plant in your zone. It's based on the average date of the last 32 degree F (0 degree C) temperature for a particular location. This 6-zone map is meant to be a guide and not a guarantee. For example, in most years, you shouldn't have any problems if you plant tomatoes in Maryland in early May, however, an unusually late frost could damage them.

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