Frost-Free Dates
Sources: USDA, "Growing Vegetables in the home," 1972, North Dakota State Univ. Extension Service. The National Arbor Day Foundation allows visitors to search by zip code for their Hardiness Zone .The top of the graphic below shows the percentage of recent change in temperatures. Planter lies in Zone 5, but our frost-free dates belie the table below. Desertification and glacial meltdown are just a hearbeat away . . .
Zone Temperature range (F) Frost-Free Date
1 below -50 ? 2 -50 to -40 June 10 3 -40 to -30 May 30 4 -30 to -20 May 20 5 -20 to -10 May 10 6 -10 to 0 Apr 30 7 0 to 10 Apr 20 8 10 to 20 Apr 10 9 20 to 30 ? 10 30 to 40 ?