Best Counties for Gardening by Growing Season

The length of the growing season is one of the most important factors for gardeners, farmers, and anyone who wants to cultivate their own food or maintain a beautiful landscape. A longer frost-free period means more time for plants to mature, more harvests per year, and a wider variety of crops to choose from.

Using NOAA climate normals and USDA hardiness zone data, we identified the 25 US counties with the longest growing seasons — places where the ground stays warm enough for plants to thrive for most of the year.

Counties with the Longest Growing Seasons

Baldwin County, AL leads the nation with undefined frost-free days per year. These counties offer gardeners and farmers an extended window for planting, growing, and harvesting.

What Growing Season Length Means for Gardeners

Counties with 300+ frost-free days can support year-round vegetable production, multiple crop rotations, and tropical or subtropical plants. Counties in the 240-300 day range support standard vegetable gardens with spring and fall plantings. Shorter seasons require cold-hardy varieties and season-extension techniques like greenhouses or row covers.

Methodology

Growing season is calculated as the number of days between the last spring frost (32°F) and the first fall frost (32°F), based on NOAA 1991-2020 climate normals. Growing Degree Days (GDD) measure heat accumulation above 50°F, indicating how much thermal energy is available for plant growth. Counties missing growing season data are excluded from the ranking.